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• Vinblastine and ajmalicine identified in endophytic fungi isolated from C. roseus. • Only Rhizoctonia solani produced ajmalicine and vinblastine alkaloids. • GC–MS analysis of extracts revealed a wide range of antimicrobial compounds. • Certain endophytic fungi could serve as sources of antioxidants. This study investigates the biodiversity of endophytic fungi in different parts of Catharanthus roseus (L.) G. Don. and their associated chemical constituents. The research also explores the potential of these endophytes as alternative sources for industrially and medically significant secondary metabolites, including indole alkaloids. Among the twelve endophytic fungi isolated from the leaves, roots, stems, petals, and callus of the periwinkle plant, seven are reported for the first time as endophytes associated with this species. The chemical profile of ethyl acetate extracts obtained from these fungal endophytes, analyzed using Gas Chromatography-Mass Spectrometry (GC–MS), revealed the presence of various compounds, including fatty acids, alcohols, esters, and phenolic compounds. Notably, vinblastine and ajmalicine alkaloids—commonly found in the host plant—were detected and quantified in fungal extracts isolated exclusively from the roots of the plant, using Liquid Chromatography-Mass Spectrometry (LC-MS). Rhizoctonia solani was found to accumulate vinblastine (0.222 µg.g⁻¹) and ajmalicine (0.335 µg.g⁻¹), while Fusarium solani accumulated ajmalicine (0.353 µg.g⁻¹), and Acrocalymma vagum accumulated vinblastine (0.255 µg.g⁻¹). Remarkably, this is the first report of vinblastine and ajmalicine accumulation in Acrocalymma vagum and Rhizoctonia solani. Furthermore, Alternaria alternata exhibited the highest total phenolic content (10.41 mg GAE.g⁻¹), and Fusarium solani showed the highest flavonoid content (0.407 mg QE.g⁻¹). The extract of Ectophoma multirostrata demonstrated the highest antioxidant activity. These findings suggest that endophytic fungi associated with C. roseus are promising sources of biologically active metabolites with diverse therapeutic applications. [ABSTRACT FROM AUTHOR]

Natural products have historically served as a rich source of potential remedies for cancer, a disease that is projected to become the leading cause of mortality. Ochrosia metabolites are potent cytotoxic drugs due to their ability to interact with nucleic acids. The scope of this review screens key features of the biological activities and phytochemical compositions of the genus Ochrosia. A comprehensive coverage of the literature has been conducted, revealing that alkaloids are the predominant metabolites, characterized by their noteworthy biological activities. Ochrosia plants also contain flavonoids, triterpenes, coumarins, resinol derivatives, and phenolic acids. Several pharmacological effects were reported, including cytotoxic, anti-inflammatory, antiviral, antiplasmodial, and antimicrobial activities. Investigation of the biological activities of ellipticines found potent anti-cancer properties, and several ellipticine derivatives have been the subject of clinical trials. Of particular interest, they have exhibited significant cytotoxic activity against various cell lines, including human breast carcinoma, leukemia cells, neuroblastoma cells, and glioblastoma cells. The ellipticine family of compounds exerts their biological activity via several modes of action, such as intercalation with DNA, topoisomerase II inhibition, interaction with the p53 transcription factor, kinase inhibition, bio-oxidation, and adduct formation. Overall, these studies highlight their diverse therapeutic potential in various types of cancer, indicating their promising role as antineoplastic agents. [Display omitted] • The genus is rich in diverse classes of compounds, especially indole alkaloids. • Flavonoids, triterpenes, sterols, coumarins, and phenolic acids were also present. • Ellipticine shows good anti-HIV, anti-inflammatory, and anticancer activities. • But it has limited clinical use owing to its low solubility and bioavailability. • Its water-soluble derivatives progressed to phase II clinical trials. [ABSTRACT FROM AUTHOR]

Humantenmine, koumine, and gelsemine are three indole alkaloids found in the highly toxic plant Gelsemium. Humantenmine was the most toxic, followed by gelsemine and koumine. The aim of this study was to investigate and analyze the effects of these three substances on tissue distribution and toxicity in mice pretreated with the Cytochrome P450 3A4 (CYP3A4) inducer ketoconazole and the inhibitor rifampicin. The in vivo test results showed that the three alkaloids were absorbed rapidly and had the ability to penetrate the blood-brain barrier. At 5 min after intraperitoneal injection, the three alkaloids were widely distributed in various tissues and organs, the spleen and pancreas were the most distributed, and the content of all tissues decreased significantly at 20 min. Induction or inhibition of CYP3A4 in vivo can regulate the distribution and elimination effects of the three alkaloids in various tissues and organs. Additionally, induction of CYP3A4 can reduce the toxicity of humantenmine, and vice versa. Changes in CYP3A4 levels may account for the difference in toxicity of humantenmine. These findings provide a reliable and detailed dataset for drug interactions, tissue distribution, and toxicity studies of Gelsemium alkaloids. • Cytochrome P450 3A4 crucially impacts the tissue distribution and elimination of the three Gelsemium alkaloids. • The three Gelsemium alkaloids were mainly distributed in the spleen and pancreas after administration. • The difference in cytochrome P450 3A4 content may account for the difference in humantenmine toxicity. [ABSTRACT FROM AUTHOR]

The crucial function of bioactive ligands in the interaction with diverse proteins has garnered significant attention in the fields of pharmacokinetics and pharmacodynamics, hence generating considerable interest in the discipline of medicinal chemistry. To better comprehend its molecular mechanism, we implored a detailed biophysical analyses (using multi-spectroscopic, calorimetric, and computational tools) of the carrier protein Lysozyme, Lyz (also known as "Muramidase") with Yohimbine (Yoh). The binding constant (K) of the Lyz-Yoh complex was estimated to be 105 M−1, exhibiting a progressive decline as temperature increased. The thermodynamic-profiling indicated the binding to be associated with an exothermic interaction driven by entropy. The confirmation of spontaneous binding is evidenced by the observed decrease in free energy. The variation in ionic strength indicated that non-polyelectrolytic forces were involved in the association. In addition, it was investigated how different metal ions affected the Lyz-Yoh binding. Calorimetric studies revealed the binding to be exothermic in nature, which also aligns with spectroscopic data. Results from circular dichroism (CD) experiments, demonstrated the structural alterations brought about in Lyz by Yoh. The likely binding sites and protein residuals to the ligand (Yoh) were illustrated using theoretical techniques, viz., molecular docking and molecular dynamic (MD) simulation. In clinical and pharmaceutical assessments, these metrics are especially relevant for rational drug development. [Display omitted] • Spontaneous and thermodynamically favorable association. • Competition between the metal ions and Yoh binding to Lyz at the same binding site. • A crucial role was played by the hydrophobic forces and hydrogen bonding. • Lyz microenvironmental changes after ligation with Yoh. [ABSTRACT FROM AUTHOR]

The widespread use of small interfering RNA (siRNA) is limited by the multiple extra- and intracellular barriers upon in vivo administration. Hence, suitable delivery systems, based on siRNA encapsulation in nanoparticles or its conjugation to targeting ligands, have been developed. Nevertheless, at the intracellular level, these state-of-the-art delivery systems still suffer from a low endosomal escape efficiency. Consequently, the bulk of the endocytosed siRNA drug rapidly accumulates in the lysosomal compartment. We recently reported that a wide variety of cationic amphiphilic drugs (CADs) can promote small nucleic acid delivery from the endolysosomal compartment into the cytosol via transient induction of lysosomal membrane permeabilization. Here, we describe the identification of alternate siRNA delivery enhancers from the NIH Clinical Compound Collection that do not have the typical physicochemical properties of CADs. Additionally, we demonstrate improved endolysosomal escape of siRNA via a cholesterol conjugate and polymeric carriers with the α1-adrenergic antagonist prazosin, which was identified as the best performing delivery enhancer from the compound screen. A more detailed assessment of the mode-of-action of prazosin suggests that a different cellular phenotype compared to typical CAD adjuvants drives cytosolic siRNA delivery. As it has been described in the literature that prazosin also induces cancer cell apoptosis and promotes antigen cross-presentation in dendritic cells, the proof-of-concept data in this work provides opportunities for the repurposing of prazosin in an anti-cancer combination strategy with siRNA. [Display omitted] • The quinazoline prazosin markedly promotes endolysosomal escape of siRNA. • The mode-of-action of prazosin differs from typical cationic amphiphilic drugs. • Improved siRNA delivery was not observed for structurally related quinazolines. • Delivery enhancement could be replicated across different nanocarrier types. • Prazosin repurposing could provide opportunities in cancer chemoimmunotherapy. [ABSTRACT FROM AUTHOR]

• Catharanthus roseus (L.) G. Don is an ornamental and medicinally important plant of apocynaceae family having large number of pharmaceutically active compounds in it. • Vinblastine and vincristine are two terpenoid indole alkaloids having anticancerous activy which are only found in C. roseus. • The biosynthetic pathway, mode of action and the limitation of these alkaloids are important to increase their production along with uses. • These alkaloids act on microtubule to restrict cell cycle of cancerous cell. The demand for natural product is growing their interest in our daily life. It makes Catharanthus roseus (L.) G. Don a crucial member of family Apocynaceae due to having its medicinal importance. It's well known for its traditional pharmacological application especially correlated with its phytochemical composition. C. roseus is a source of vast phytochemicals including alkaloids, essential oils, phenols, carbohydrates, saponins and flavonoids, but alkaloids are the predominant phytochemicals with their medicinal activity. Interestingly, C. roseus is the only source of vinblastine (VLB) and vincristine (VCR), two main medicinally sound expensive anti-cancerous bis-indole alkaloids showing their activity as mitotic poisons. They cause mitotic arrest by disrupting microtubules. The present review deals with vis-à-vis outline of VLB and VCR with their biosynthesis, extraction, detection, mode of action and their limitation. It helps to increase the knowledge on its mechanism to arrest tumour cell growth along with their side effects during over doses. As well as the lacuna and their future directions will be discussed for future research. Though these are required in a very minute quantity for the treatment, but it is important to increase the production of these two costly alkaloids by using cost effective biotechnological methods. [ABSTRACT FROM AUTHOR]

• Callus induction in woody plant N. nimmoniana using phytohormone Thidiazuron (TDZ). • Establishment of callus culture for efficient production of anticancerous monoterpene indole alkaloid Camptothecin. • TDZ induces synthesis of Camptothecin in concentration dependent manner. Nothapodytes nimmoniana is an endangered medicinal plant known for the synthesis of the anti-cancer drug Camptothecin (CPT). Although CPT is considered as a great boon to cancer therapy, its commercial production relies entirely on naturally occurring plant sources. This resulted in the rampant harvesting of the N. nimmoniana plant population, making the plant endangered. The in vitro system of callus induction and culture faces several challenges, such as recalcitrancy and reduction in CPT content in N. nimmoniana. Here, we report Thidiazuron (TDZ) induced callogenesis and the effect of its different concentrations on the CPT content in the callus. The best explant for callogenesis was found to be hypocotyl, followed by leaf. The TDZ, in combination with 2,4-D, was the most effective among all plant growth regulators combinations tested. The TDZ could induce callus at 1 and 2 mg/L concentrations combined with 0.5 mg/L 2,4-D. The CPT content of the calli maintained on 2 mg/L TDZ+0.5 mg/L 2,4-D was two-fold higher than that of calli on 1 mg/L TDZ+0.5 mg/L 2,4-D. The callus cultures maintained at the selected medium were growing with no signs of organogenesis and necrosis even after multiple sub-cultures. The finding of the experiment emphasizes that TDZ not only induces callogenesis but may also induce CPT biosynthesis in a dose-dependent manner. The results can further be utilized to develop N. nimmoniana callus culture with high CPT content using variable concentrations of TDZ combined with elicitor treatments. [ABSTRACT FROM AUTHOR]

• Sixteen CPT intermediates from nothapodytes nimmoniana were identified and confirmed. • Isomers of CPT post-strictosidine intermediates were relatively quantified in root, bark, fruit and leaf. • Roots accumulated most of the CPT intermediates. • Both carboxylic acid and methyl ester forms of CPT intermediates are present in N. nimmoniana. Nothapodytes nimmoniana is a medicinally important plant producing camptothecin (CPT) which is a well-known anti-cancer drug. Its analogues viz. topotecan and irinotecan are currently used to treat variety of cancers like lung, colon, ovarian cancers. The CPT is a monoterpene indole alkaloid class of compound and synthesised by the combination of terpene and indole pathway. Secologanin from terpene pathway and tryptamine from indole pathway condense together to form strictosidine which is a precursor of CPT. In this study, four different tissues viz. root, leaf, bark and fruit of N. nimmoniana were subjected to LC-QTOF-MS analysis. Total sixteen intermediate compounds in the CPT biosynthetic pathway with their relative accumulation were detected and confirmed by tandem mass spectrometry analysis. Two or more than two isomers of post-strictosidine pathway intermediates like deoxypumiloside, pumiloside and strictosamide, strictosamide epoxide were detected in roots and bark. Accumulation pattern of intermediate metabolites in roots suggests active biosynthesis of CPT in roots. Moreover, unlike Camptotheca acuminata (another CPT producing plant), presence of both carboxylic acid derivatives and methyl esters of iridoid pathway intermediates such as loganic acid/ loganin, secologanic acid/ secologanin and strictosidinic acid/ strictosidine suggests existence of two or more interwoven pathways leading to CPT biosynthesis in N. nimmoniana. [ABSTRACT FROM AUTHOR]

Two new indole alkaloids, colletotryptins G (1) and H (2), along with four known alkaloids (3 – 6), were isolated from an endophytic fungus Colletotrichum sp. HD-1 (Melanconiaceae) derived from the mangrove plant Acrostichum aureum (Pteridaceae). The structures of new compounds were elucidated by comprehensive analysis of their UV, HRESIMS, and NMR data. All the isolates were evaluated for their α -glucosidase and acetylcholinesterase inhibitory, antibacterial, and antifungal activities. Only compound 2 showed stronger inhibitory activity against α -glucosidase with IC 50 value of 133.4 μM than that of the positive control acarbose (319.8 μM). [Display omitted] • Indole alkaloids are the main metabolites of endophytic fungus Colletotrichum sp. • Two new indole alkaloids (1 and 2) were isolated and identified from this fungus. • Compound 2 showed better α -glucosidase inhibitory activity than acarbose. [ABSTRACT FROM AUTHOR]

Endometrial receptivity is a critical process for the successful establishment of pregnancy in ruminants. However, the biological role of long non-coding RNAs (lncRNAs) in the development of endometrial receptivity is poorly understood. In this study, we performed RNA-seq analysis of immortalised goat endometrial epithelial cells (gEECs) treated with interferon-τ (IFNT). Transcriptome profiles showed that 8069 high-confidence putative lncRNAs, including 6498 intronic lncRNA transcripts, 1078 lincRNAs and 493 antisense lncRNAs were identified in gEECs with or without IFNT treatment. Functional clustering analysis was performed by using cis and trans lncRNAs prediction. GO and KEGG analyses revealed that differentially expressed lncRNAs may regulate tissue remodelling and immune responses. Subsequently, six of the 21 differentially expressed antisense lncRNAs were validated using qRT-PCR. Through functional screening and co-expression analysis of lncRNAs in gEECs, we identified that ISG15-AS was mainly expressed in the luminal and glandular epithelium on days 5 and 15 and was strongly upregulated on day 18 of pregnancy in vivo. Similarly, ISG15-AS was abundant in the nucleus and cytoplasm, and was significantly upregulated after treatment with IFNT in gEECs. In addition, ISG15 is an IFNT-responsive gene, that displayed an evident increase in vivo and in vitro. Moreover, sense ISG15 was significantly upregulated following ISG15-AS silencing. The key genes related to ISGylation and endometrial receptivity in gEECs dramatically increased after ISG15-AS inhibition. Collectively, our results indicate that a novel antisense lncRNA, ISG15-AS, may be important in regulating endometrial receptivity through ISGylation. • Systematic identification and analysis of lncRNAs in IFNT treated gEECs was identified by high-throughput RNA-sequencing. • The expression of ISG15-AS in gEECs were strongly upregulated by IFNT during embryo implantation. • ISG15-AS significantly activated formation of endometrium receptivity in gEECs through ISGylation. [ABSTRACT FROM AUTHOR]

Catharanthus roseus is a perennial herb of the Apocynaceae family, from which about 200 kinds of alkaloids have been characterized. Most alkaloids from C. roseus are terpenoid indole alkaloids (TIAs), such as vinblastine and vincristine, which are widely used in the clinic for their good antitumor activity. However, they were only biosynthesized in C. roseus, and their content in C. roseus is extremely low. The access to these valuable compounds is by plant extraction or chemical semisynthesis from their precursors catharanthine and vindoline. Since catharanthine and vindoline are also obtained from C. roseus, the supply of vinblastine and vincristine makes it difficult to meet market demands. Therefore, how to improve the yield of TIAs is an attractive issue. In this study, we compared the regulatory effect of two critical transcription factors, octadecanoid-derivative responsive Catharanthus AP2-domain protein 3 (ORCA3) and octadecanoid-derivative responsive Catharanthus AP2-domain protein 4 (ORCA4), on the biosynthesis of TIAs in C. roseus. The results showed that overexpressing both two transcription factors could increase the accumulation of TIAs. The effect was more significant when ORCA4 was overexpressed. To acquire C. roseus TIAs on a continuous and consistent basis, we then created and acquired C. roseus stem cells stably overexpressing ORCA4. This is the first time a recombinant C. roseus stem cell system with stable ORCA4 overexpression has been developed, which not only provides new ideas for future research in this area but also breaches new life into the industrial application of using plant cell culture to obtain natural products. [Display omitted] • Transcription factor ORCA3 regulated the expression of ORCA4 in Catharanthus roseus. • ORCA4 overexpression resulted in accumulation of catharanthine and vindoline. • C. roseus stem cells overexpressing ORCA4 were built for the first time. • Overexpressing ORCA4 is beneficial for terpenoid indole alkaloids biosynthesis. [ABSTRACT FROM AUTHOR]

• Elicitation is an important strategy to get better productivity of secondary metabolites and for reducing production costs. • Ca2+ is very important macro-nutrient and key second messenger in signal transduction. • Elicitation is used to elucidate the complex metabolic pathways. • The biosynthesis of indole alkaloids in C. roseus cell cultures is associated to Ca2+influx and oxidative burst. Elicitation is an important strategy to get better productivity of secondary products and reducing production costs. In this study CaCl 2 was used as an elicitor for the enhancement of Vinblastine synthesis in Catharanthus roseus embryogenic cell suspension culture. Various concentrations (0 mM-100 mM) of CaCl 2 were added in Murashige and Skoog (MS) medium. Cell growth attributes were measured in terms of growth efficiency and packed cell volume (PCV). The growth efficiency of the callus was decreased as the numbers of days were increased whereas settled cell and PCV% increased with time. With increase in CaCl 2 concentration, the medium pH was decreased linearly in all days of treatments and minimum pH was recorded after 30 days of culture. There was a progressive increase in protein as well as free proline content with increasing concentration of CaCl 2 whereas the amino acid content was found to decrease. The sugar content increased and showed a linear trend up to 75 mM CaCl 2 thereafter it declined. As compare to control, an increase of 1% to 17.99% of vinblastine was recorded after 30 days of culture. This clearly indicates the importance of this work as a lead for vinblastine synthesis in liquid culture. [ABSTRACT FROM AUTHOR]

Chemical investigation of the native medicinal plant Tabernaemontana bovina led to the isolation of five previously unreported monoterpenoid indole alkaloids tabernovinaines A-E (1 – 5) together with twenty-seven known analogs (6 – 32), including a bisindole alkaloid 1 with the (E)-4-aminobut-3-en-2-one fragment, as well as a unique cage skeleton 2 containing 6/5/8/6/6 ring system. The chemical structures of these unreported compounds were elucidated using mass spectrometry, NMR spectroscopy, circular dichroism, density functional theory calculations, and derivatizations. The activity evaluation shows that the bisindole alkaloid 1 revealed a potential cytotoxic effect by inducing HepG2 cell apoptosis and damaging clonal sphere expansion. Five undescribed monoterpenoid indole alkaloids tabernovinaines A-E were isolated and characterized from the Tabernaemontana bovina , and tabernovinaine A had certain cytotoxic activities. [Display omitted] • Five previously unreported monoterpenoid indole alkaloids were isolated from Tabernaemontana bovina. • Compound 1 was the first reported bisindole alkaloid with the (E)-4-aminobut-3-en-2-one fragment. • Compound 2 was identified as a unique cage skeleton containing 6/5/8/6/6 ring system. • The bisindole alkaloid 1 with potential antitumor effection. [ABSTRACT FROM AUTHOR]

The (sub-)tropical mosquito species Culex quinquefasciatus Say (Diptera: Culicidae) is a major vector for various parasitic and viral zoonotic diseases that pose a significant threat to human health. One promising source of effective and environmentally sustainable botanical insecticides against mosquitoes is the pantropical genus Tabernaemontana L. (Apocynaceae), which includes approximately 100 woody species known for producing bioactive monoterpenoid indole alkaloids (MIAs). We analyzed the alkaloid profile and insecticidal properties of a total alkaloid extract (TAE) obtained from the root bark of Tabernaemontana arborea ROSE ex J.D.SM. (Apocynaceae) against C. quinquefasciatus. According to gas chromatography-mass spectrometry (GC-MS), voacangine, ibogaine, vobasine, and coronaridine (82.99 %, 5.33 %, 4.62 %, and 1.97 % of the TAE's dry weight, respectively) were the main constituents of the TAE (2.42 % of the bark's dry weight), which demonstrated significant larvicidal activity (LC 50,90 = 1.56, 8.36 µg/mL, 2.75, 13.42 µg/mL, and 3.29, 13.95 µg/mL for the second, third, and fourth instar, respectively). Both lethal and sublethal doses reduced the fecundity and vitality of the surviving mosquitoes without affecting the aquatic non-target species Daphnia magna Straus (Anomopoda: Daphniidae). Given the high yields of root bark and TAE, T. arborea shows promise as a source of sustainable botanical insecticides. It is a non-threatened species that thrives in disturbed areas across tropical and subtropical Mexico and can be easily propagated from seeds. However, further research, including laboratory and especially field studies, is needed to develop standardized formulations with MIAs from T. arborea that are effective, safe, and environmentally friendly. • A Tabernaemontana arborea alkaloid extract was toxic to Culex quinquefasciatus larvae. • (Sub-)lethal doses reduced the fecundity and vitality of the surviving mosquitoes. • The extract did not affect the aquatic non-target species Daphnia magna. • T. arborea shows promise as a source of sustainable botanical insecticides. [ABSTRACT FROM AUTHOR]

Five previously undescribed indole alkaloids, maeruines A−E (1 − 5), bearing imino-2 H -thieno[2,3- b ]indol-3(8 H)-one skeleton, were obtained from the stems of Maerua siamensis. Their chemical structures were elucidated using spectroscopic techniques [NMR, MS, IR, and UV], and single-crystal X-ray diffraction. Maeruine D (4) displayed selective cyclooxygenase-2 (COX-2) inhibitory activity in vitro with an IC 50 of 29.72 ± 6.36 μM. Molecular dynamics simulations revealed that maeruine D could form a stable complex with human COX-2, predominantly driven by hydrophobic interactions. In addition, five amino-acid residues including Val349, Leu352, Leu384, Val523, and Ala527 were identified as hot-spot ones, which may lead to high binding affinity and selectivity. Furthermore, it exhibited cytotoxicity against HT-29 colorectal cancer cells with an IC 50 of 29.32 ± 4.76 μM, and, at 0.1−10 μM, significantly inhibited their proliferation, induced by the proinflammatory cytokine interleukin-1β (IL-1β), in a dose-dependent manner. Maeruine D (4) displayed selective COX-2 inhibitory activity in vitro via hydrophobic interactions and significantly inhibited HT-29 colorectal cancer cell proliferation, induced by IL-1β. [Display omitted] • Five alkaloids with imino-2 H -thieno[2,3- b ]indol-3(8 H)-one skeleton were discovered. • Maeruine D displayed selective cyclooxygenase-2 inhibitory activity in vitro. • Maeruine D exhibited cytotoxicity against HT29 colorectal cancer cells. [ABSTRACT FROM AUTHOR]

Camptothecin (CAM), a well-known plant-derived antitumor compound, is a structurally complex pentacyclic pyrroloquinoline monoterpene indole alkaloid (MIA) found in various plant species. As a specific MIA, CAM had been thought to share a common upstream biosynthetic pathway with other MIAs such as the antitumor vinblastine and vincristine from Catharanthus roseus. Nevertheless the key enzymes responsible for the consecutive three-step oxidation of the –CH 3 of nepetalactol to form the –COOH of 7-deoxyloganetic acid and the subsequent glycosylation of 7-deoxyloganetic acid to yield 7-deoxyloganic acid have yet to be functionally characterized. Here we established an in vivo tandem catalysis assay for the enzymatic catalytic activity characterization of 7-deoxyloganetic acid synthase (7DLS) and 7-deoxyloganetic acid glucosyltransferase (7DLGT), two crucial catalytic enzymes in MIAs biosynthesis, thereby avoiding the difficulty in the detection of the unstable biosynthetic intermediates. The enzyme activity assay platform was conducted through the co-expression of functionally characterized Cr7DLS and Cr7DLGT in Saccharomyces cerevisiae WAT11, substrate feeding, and enzymatic product verification. Two cytochrome P450 enzymes (CYPs) from Camptotheca acuminata , the prestigious resource for CAM, CaCYP76A75 and CaCYP76A76, were identified and functionally characterized to be responsible for the consecutive three-step oxidation of nepetalactol to yield 7-deoxyloganetic acid through reciprocal replacement of Cr7DLS in the in vivo tandem enzyme activity assay platform. Two uridine 5′-diphosphate glycosyltransferases (UGTs), CaUGT709C10 and CaUGT709C11, were functionally characterized to be capable of glycosylating 7-deoxyloganetic acid to yield 7-deoxyloganic acid. This study provides two CYPs as 7DLSs and two UGTs as 7DLGTs, offering potential applications in MIAs biosynthesis. [Display omitted] • An in vivo tandem catalysis was established for enzyme's functional characterization. • CYP76A75 and CYP76A76 were identified and functionally characterized as Ca7DLSs. • UGT709C10 and UGT709C11 were identified and functionally characterized as Ca7DLGTs. [ABSTRACT FROM AUTHOR]

We describe the first successful synthesis of the indole alkaloid isolated from the marine sponge Halichondria melanodocia , using the previously unreported nickel catalyzed cross electrophile coupling of an α-bromoketone to a sp 2 iodide to provide a convergent synthesis of the carbon framework without concomitant olefin migration. The indole alkaloid was thus synthesized in two steps from known compounds. [Display omitted] • Our paper reports the first synthesis of the indole alkaloid from the marine sponge Halichondria melanodocia. [ABSTRACT FROM AUTHOR]

Natural products (NPs) often act as sources of CNS-active agents and provide inspiration for the development of synthetic molecules that incorporate their best features. Vindeburnol (VIND; (±)-(3 α ,14 β)-20,21-dinoreburnamenin-14-ol; developmental codes RU24722 or BC19), based on the core structure of eburnamine-vincamine alkaloids, has been extensively investigated for its biological activities. This molecule has demonstrated potential therapeutic properties in various in vivo models of CNS disorders such as multiple sclerosis, Alzheimer's disease, and depressive-like behavior. Although few clinical trials were conducted, further development of vindeburnol was abandoned. This review presents synthetic approaches to vindeburnol synthesis as well as the most complete discussion of its pharmacological effects. Studies involving vindeburnol in animal models of CNS disorders and a few human trials have been presented in separate sections. Special attention is placed on derivatives and analogs based on the vindeburnol scaffold. The interesting pharmacological profile of vindeburnol suggests that this NP-inspired compound may serve as a useful tool or structural basis for next-generation molecules in CNS drug design and discovery. [Display omitted] • Indole alkaloid vindeburnol active in in vivo models of CNS disorders. • It's scaffold is basis for CNS drug discovery. [ABSTRACT FROM AUTHOR]

• E. aureum has the ability to resist and remediate Cu contamination. • Proline and hydroxyproline favor E. aureum resistance to Cu stress. • E. aureum improves its resistance to Cu stress by promoting BR synthesis. • E. aureum regulates oxidative homeostasis by promoting indole alkaloid synthesis. • Combining metabolomics and RSM to propose precisely optimized remediation protocols. Phytoremediation is commonly used to remediate copper (Cu) pollution in water bodies. Epipremnum aureum is often used as a restoration plant because of its rapid reproduction, high population density and high landscape value. However, neither its ability to remediate Cu-polluted water nor its mechanism of resistance to Cu stress has been fully clarified. Therefore, the present study revealed the Cu removal ability and resistance mechanism of E. aureum through physiology and metabolomics. And based on the results of this study, the response surface was applied to the application of plant growth regulator (PGR) to propose a precise restoration program. We first examined the growth physiological indices and repair of Cu in E. aureum under different Cu stress levels and found that the resistance mechanism of E. aureum to Cu was significantly initiated at 400 mg·L-1. And as the level of Cu stress increased, the Cu content in the plant also increased, and the underground part was the main accumulating part. The translocation factor of E. aureum was <1, and the bioconcentration factor was greater than 1 at all different Cu concentrations. Subsequently, metabolomics studies on E. aureum concluded that arginine and proline metabolism, indole alkaloid synthesis and brassinosteroid biosynthesis are the major pathways involved in the mechanism of Cu stress resistance in E. aureum. Based on these results, we proposed that salicylic acid, sodium nitroprusside and 2,4-epibrassinolide could be selected as PGRs, and further optimized the administration of PGRs using response surfaces. The optimized scheme allowed E. aureum to reach a maximum Cu removal of 84.39 % under 400 mg·L-1 Cu stress, which was 35.61 % higher than the non-fortified treatment. This study provides supporting materials and application options for the Cu repair capacity and resistance mechanisms of E. aureum. [Display omitted] [ABSTRACT FROM AUTHOR]

The monoterpenoid oxindole alkaloids (MOA) are specialized plant metabolites of pharmacological importance, whose biosynthesis is linked to a unique oxidative process of monoterpenoid indole alkaloids (MIA). These transformations arise from complex biosynthetic pathways defined by species, organs, tissues, and growth stages. Initial studies of their biosynthesis using labeled precursors date back more than five decades ago. This review shows the advances in this topic within the years 2022–2023, which highlight the research by integrative omics strategies, validating previously stated hypotheses. The MOA biosynthesis pathway is beginning to be elucidated, especially in the early and intermediate stages starting from MIA. Also, progress in the characterization of enzymes that regulate the process has been made. The discovery of a key enzyme in the formation of the spirooxindole scaffold represents a starting point for an enormous amount of work that remains to be done to clarify and understand the formation mechanisms of MOA. [ABSTRACT FROM AUTHOR]

Leading by the antiviral activities against HSV-2 virus, bioactivity-guided the fraction of crude alkaloids from seeds of Peganum harmala led to the isolation of nine structurally novel indole alkaloids, pegaharolines A − I (1 – 9), and 11 known ones (10 − 20). Compound 3 was an unusual 6/5/5/5 spirotetracyclic indole-derived alkaloids featuring a classic bicyclic indole unit fused with an additional pyrrolizine ring via a spiral atom (C-3). Compound 4 was determined as a novel indole alkaloid, characterized with a rare hexacyclic 6/5/6/5–6/6 ring system, by a single-crystal X-ray diffraction. Compounds 5 and 6 were peculiar indole dimers featuring with the rare carbon skeleton of an octacyclic scaffold. Compounds 1 – 6 were six racemates. Most compounds exhibited different levels of antiviral activities against HSV-2. Especially, the anti-HSV-2 activity of compound 1 (IC 50 = 0.90 ± 0.10 μM) was much better than that of the positive control (acyclovir, IC 50 = 1.12 ± 0.15 μM). In this study, the discovery of anti-HSV-2 components from the seeds of P. harmala , could benefit development and utilization of this plant in antiviral medicinal products. [Display omitted] [ABSTRACT FROM AUTHOR]

Mitragynine (MTG) is a prominent indole alkaloid that is present abundantly in Mitragyna speciosa , commonly referred to as kratom. MTG has garnered significant attention due to its selective agonistic characteristics towards opioid receptors and related analgesic effects. In the circulatory system, the in vivo efficacy of MTG is dictated by its interaction with plasma proteins, primarily human serum albumin (HSA). In the present study, we utilized a broad methodology that included spectroscopic, calorimetric, microscopic, and in silico approaches to characterize the interaction between MTG and HSA. Alterations in the UV absorption spectrum of HSA by the presence of MTG demonstrated a ground-state complexation between the protein and the ligand. The K a values obtained for the MTG–HSA interaction were in the range 103–104 M−1 based on analysis of fluorescence and ITC data, respectively, indicating an intermediate binding affinity. The binding reaction was thermodynamically favorable as revealed by Δ H , Δ S , and Δ G values of −16.42 kJ mol−1, 39.97 J mol−1 K−1, and −28.34 kJ mol−1, respectively. Furthermore, CD spectroscopy results suggested MTG binding induced minimal effects on the structural integrity of HSA, supported by computational methods. Changes in the dimensions of HSA particles due to aggregation, as observed using atomic force microscopy in the presence of MTG. Competitive drug displacement results seemingly suggested site III of HSA located at subdomain IB as the preferred binding site of MTG, but were in inconclusive. However, docking results showed the clear preference of MTG to bind to site III, facilitated by hydrophobic (alkyl and pi-alkyl) and van der Waals forces, together with carbon hydrogen bonds. Additionally, the MTG–HSA complexation was demonstrated to be stable based on molecular dynamics analysis. The outcomes of this study shed light on the therapeutic potential of MTG and can help in the design of more effective derivatives of the compound. [Display omitted] • MTG binds to HSA with moderate affinity. • MTG likely binds to HSA at site III in subdomain IB. • Structural integrity of HSA is unaffected by MTG complexation. • MTG–HSA complexation is energetically favorable and stable. [ABSTRACT FROM AUTHOR]

Plant-derived monoterpene indole alkaloids (MIAs) from Uncaria rhynchophylla (UR) have huge medicinal properties in treating Alzheimer's disease, Parkinson's disease, and depression. Although many bioactive UR-MIA products have been isolated as drugs, their biosynthetic pathway remains largely unexplored. In this study, untargeted metabolome identified 79 MIA features in UR tissues (leaf, branch stem, hook stem, and stem), of which 30 MIAs were differentially accumulated among different tissues. Short time series expression analysis captured 58 pathway genes and 12 hub regulators responsible for UR-MIA biosynthesis and regulation, which were strong links with main UR-MIA features. Coexpression networks further pointed to two strictosidine synthases (UrSTR1/5) that were coregulated with multiple MIA-related genes and highly correlated with UR-MIA features (r > 0.7, P < 0.005). Both UrSTR1/5 catalyzed the formation of strictosidine with tryptamine and secologanin as substrates, highlighting the importance of key residues (UrSTR1 : Glu309, Tyr155; UrSTR5 : Glu295, Tyr141). Further, overexpression of UrSTR1/5 in UR hairy roots constitutively increased the biosynthesis of bioactive UR-MIAs (rhynchophylline, isorhynchophylline, corynoxeine, etc), whereas RNAi of UrSTR1/5 significantly decreased UR-MIA biosynthesis. Collectively, our work not only provides candidates for reconstituting the biosynthesis of bioactive UR-MIAs in heterologous hosts but also highlights a powerful strategy for mining natural product biosynthesis in medicinal plants. [ABSTRACT FROM AUTHOR]

• Alstonine is an indole alkaloid found abundantly in some traditional plants. • Alstonine has chemotherapeutic properties by acting as an intercalating agent and inducing apoptosis and DNA damage in cancer cells. • Alstonine also has antipsychotic properties, mostly through its ability to increase serotonergic transmission. • Alstonine's anxiolytic and antiplasmodial properties have been shown to involve inhibiting haloperidol-induced catalepsy and the subsequent mediation of mitochondrial apoptosis. Alstonine is an indole alkaloid found abundantly in some traditional plants. In some parts of the world, including Nigeria and India, plants containing alstonine have been used to cure mental illness, dysentery, and typhoid, among others. The current review describes the pharmacological activities of alstonine. The search phrases "alstonine," "biological activity," and "pharmacological activity" were used to query Google Scholar, PubMed Central, Web of Science, Scopus, and Base databases. It was established that alstonine has chemotherapeutic properties by acting as an intercalating agent and inducing apoptosis and DNA damage in cancer cells. In addition, alstonine has antipsychotic properties, mostly through its ability to increase serotonergic transmission while simultaneously altering dopamine metabolism. Furthermore, alstonine's anxiolytic and antiplasmodial properties have been shown to involve inhibiting haloperidol-induced catalepsy and the subsequent mediation of mitochondrial apoptosis in Plasmodium falciparum. In spite of its interesting biological activities, several aspects of alstonine properties such as toxicity and pharmacokinetics are relatively underreported. [ABSTRACT FROM AUTHOR]

• Catharanthus roseus (L.) G. Don is a classified high-value, low-volume medicinal herb. • It is the sole source of anticancer drug vinblastine and vincristine. • This review discusses pharmacological properties of alkaloids and some non-alkaloids. • Also discuss their potential efficacy in clinical trials, and future prospects in the treatment of multiple human disorders. The rising incidence of human diseases has necessitated the exploration of alternative sources of medications, with a refocus and exploration of plant-based metabolites demonstrating pharmacological attributes. Catharanthus roseus (L.) G. Don, popularly known as Madagascar Periwinkle, constitutes an attractive source of monoterpene indole alkaloids (MIAs), vincristine, and vinblastine and analogs demonstrating efficacy in the treatment of multiple disorders. Considering the emerging prospects and global demands of C. roseus alkaloids, the thematic review provides extensive insights into the biosynthesis of alkaloids in the plant via multiple metabolic pathways. This review extensively discusses the pharmacological properties of MIAs and some non-alkaloids, their potential efficacy in clinical trials, and future prospects of the bioactive metabolites in the treatment of multiple human disorders. [ABSTRACT FROM AUTHOR]

During mammary development, the transdifferentiation of mammary preadipocytes is one of the important sources for lactating mammary epithelial cells (MECs). However, there is limited knowledge about the mechanisms of dynamic regulation of transcriptome and genome-wide DNA methylation in the preadipocyte transdifferentiation process. Here, to gain more insight into these mechanisms, preadipocytes were isolated from adipose tissues from around the goat mammary gland (GM-preadipocytes). The GM-preadipocytes were cultured on Matrigel in conditioned media made from goat MECs to induce GM-preadipocyte-to-MEC transdifferentiation. The transdifferentiated GM-preadipocytes showed high abundance of keratin 18, which is a marker protein of MECs, and formed mammary acinar-like structures after 8 days of induction. Then, we performed transcriptome and DNA methylome profiling of the GM-preadipocytes and transdifferentiated GM-preadipocytes, respectively, and the differentially expressed genes and differentially methylated genes that play underlying roles in the process of transdifferentiation were obtained. Sub-sequently, we identified the candidate transcription factors in regulating the GM-preadipocyte-to-MEC transdifferentiation by transcription factor-binding motif enrichment analysis of differentially expressed genes and differentially methylated genes. Meanwhile, the secretory proteome of GM-preadipocytes cultured in conditioned media was also detected. By integrating the transcriptome, DNA methylome, and proteome, three candidate genes, four proteins, and several epigenetic regulatory axes were further identified, which are involved in regulation of the cell cycle, cell polarity establishment, cell adhesion, cell reprogramming, and adipocyte plasticity. These findings provide novel insights into the molecular mechanism of preadipocyte transdifferentiation and mammary development. [ABSTRACT FROM AUTHOR]

Terpene indole alkaloids (TIAs) are plant-derived specialized metabolites with widespread use in medicine. Species-specific pathways derive various TIAs from common intermediates, strictosidine or strictosidinic acid, produced by coupling tryptamine with secologanin or secologanic acid. The penultimate reaction in this pathway is catalyzed by either secologanin synthase (SLS) or secologanic acid synthase (SLAS) according to whether plants produce secologanin from loganin or secologanic acid from loganic acid. Previous work has identified SLSs and SLASs from different species, but the determinants of selectivity remain unclear. Here, combining molecular modeling, ancestral sequence reconstruction, and biochemical methodologies, we identified key residues that toggle SLS and SLAS selectivity in two CYP72A (cytochrome P450) subfamily enzymes from Camptotheca acuminata. We found that the positions of foremost importance are in substrate recognition sequence 1 (SRS1), where mutations to either of two adjacent histidine residues switched selectivity; His131Phe selects for and increases secologanin production whereas His132Asp selects for secologanic acid production. Furthermore, a change in SRS3 in the predicted substrate entry channel (Arg/Lys270Thr) and another in SRS4 at the start of the I-helix (Ser324Glu) decreased enzyme activity toward either substrate. We propose that the Camptotheca SLASs have maintained the broadened activities found in a common asterid ancestor, even as the Camptotheca lineage lost its ability to produce loganin while the campanulid and lamiid lineages specialized to produce secologanin by acquiring mutations in SRS1. The identification here of the residues essential for the broad substrate scope of SLASs presents opportunities for more tailored heterologous production of TIAs. [ABSTRACT FROM AUTHOR]

Voagafries A–E, five undescribed monoterpenoid indole alkaloids (MIAs), were isolated from the stem bark of Voacanga africana. Voagafrie A (1) has a unique 6/5/5/6/6 spiral ring skeleton with an indolone-fused 9-oxo-3-aza-tricyclo[6,3,1,03,7]-12-alkane-10-carbonyllactone. Voagafrie B (2) is a rare 5,6-seco diazine scaffold, whereas voagafrie C (3) possesses an octahydropyrrolo[2,3-b] pyrrole-fused 2,8-diazabicyclo[3.3.1] nonane. In addition, voagafrie D (4) represents an additional 3C ibogamine-type MIA. Their structures were elucidated using extensive spectroscopic and computational analyses and a plausible biosynthetic pathway originating from conopharyngine was proposed. Furthermore, voagafries B (2) and E (5) exhibited significant cytotoxicity against SH-SY5Y at 10 μmol/L with cell viabilities of 72.7 ± 3.8 and 79.5 ± 2.1, respectively, which were comparable to that of the positive drug paclitaxel (64.1 ± 0.9). Based on the research on several cell death-related factors, these compounds may be involved in apoptosis; therefore, it is necessary to advance our understanding of them through future studies. Five undescribed monoterpenoid indole alkaloids Voagafries A–E (1–5) were obtained from Voacanga africana. Voagafries B and E (2 and 5) exhibited significant cytotoxicity against glioma cell SH-SY5Y. [Display omitted] • Five undescribed indole alkaloids were obtained from Voacanga africana. • Structures of five compounds were confirmed by spectroscopy and ECD analyses. • Compound 1 possesses an unprecedented 6/5/5/6/6 spiral ring skeleton. • 2 and 5 exhibited potent anti-glioma activity by regulating apoptotic pathway. [ABSTRACT FROM AUTHOR]

[Display omitted] Achieving the synthesis of densely-functionalized, cage-like alkaloids has long proven quite challenging, with the success of individual events often being acutely sensitive to minute differences in the geometry and strain of the substrate, particularly as each successive ring is constructed. As such, consideration of what ring to form last has proven to be of particular design significance. In this review, we analyze seminal examples where the E-ring of various structurally related caged indole alkaloids has been targeted as the site of terminal ring closure. As these examples demonstrate, a terminating E-ring approach can enable highly efficient syntheses, but often bespoke solutions are required, given the near-consistent failure of conventional cyclization strategies to forge such rings. [ABSTRACT FROM AUTHOR]

The butyrylcholinesterase (BChE) is an attractive target for treating Alzheimer's disease. In this study, we report the discovery of five new monoterpene indole alkaloids (MIAs) along with three known analogues from Uncaria sessilifructus Roxb. as BChE inhibitors using affinity ultrafiltration based metabolomic profiling directed isolation strategy. Their structures were well identified through comprehensive spectroscopic and chiroptical analyses. Compounds 1 – 2 featured unique glycosidic linkages with 1,3-dioxane structure. All the compounds exhibited BChE inhibitory bioactivity without any cytotoxic effects. Enzymatic kinetic and molecular docking analyses of compounds 1 and 6 demonstrated their inhibiting mechanisms and binding patterns to BChE. These findings provide a valuable workflow for efficiently screening ligands that bind to proteins, and scientific recognition in the discovery of BChE inhibitors for treating neurodegenerative disorders. [ABSTRACT FROM AUTHOR]

Zuojin Pill (ZJP), a traditional Chinese medicine prescription composed of Rhizoma Coptidis and Euodiae Fructus in the ratio of 6:1 (w/w), has been widely used for the treatment of gastric disorders. However, an in-depth understanding of in vivo metabolism and distribution profiles of protoberberine alkaloids (PBAs) and indole alkaloids (IDAs) in ZJP is lacking. In this study, a method using ultra-high performance liquid chromatography coupled with quadruple time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) was developed to systematically screen the alkaloids and their metabolites in rat plasma and various tissues after oral administration of ZJP. Furthermore, bioinformatics and molecular docking analyses were conducted to elucidate the contribution of the alkaloids and metabolites enriched in the stomach to the therapeutic effect of ZJP on gastritis. A total of 33 compounds, including 7 prototype alkaloids and 26 metabolites, were chemically defined or tentatively identified in this work. The metabolic pathways of PBAs (hydroxylation, oxidation, reduction, demethylation, demethylenation, glucuronide conjugation, sulfate conjugation) and IDAs (hydroxylation, glucuronide conjugation) were revealed. Notably, 7 prototype alkaloids and 18 metabolites were detected in the stomach, indicating their propensity for gastric distribution. These alkaloids and metabolites showed strong affinities with the 7 hub targets associated with gastritis, such as CCR7, CXCR4, IL6, IFNG, CCL2, TNF, and PTPRC, and could be considered the potential active substances of ZJP for treating gastritis. In conclusion, this study clarified the gastric distribution propensity of PBAs and IDAs and their metabolites, as well as their favorable binding interactions with gastritis-related targets, which could provide essential data for the further study of the pharmacodynamic material basis and gastroprotective mechanism of ZJP. [Display omitted] • The metabolism and distribution profiles of ZJP were characterized by UHPLC-Q-TOF-MS. • 7 prototype alkaloids and 26 related metabolites were identified. • 7 hub targets associated with gastritis were screened by bioinformatics. • Compounds enriched in the stomach showed strong affinities with 7 hub targets. [ABSTRACT FROM AUTHOR]

Mitragynine, an alkaloid present in the leaves of Mitragyna speciosa (kratom), has a complex pharmacology that includes low efficacy agonism at μ-opioid receptors (MORs). This study examined the activity of mitragynine at adrenergic α 2 receptors (Aα 2 Rs) in vitro and in vivo. Mitragynine displaced a radiolabeled Aα 2 R antagonist ([3H]RX821002) from human Aα 2A Rs in vitro with lower affinity (K i = 1260 nM) than the agonists (−)-epinephrine (K i = 263 nM) or lofexidine (K i = 7.42 nM). Mitragynine did not significantly stimulate [35S]GTPγS binding at Aα 2A Rs in vitro , but in rats trained to discriminate 32 mg/kg mitragynine from vehicle (intraperitoneally administered; i.p.), mitragynine exerted an Aα 2 R agonist-like effect. Both α 2 R antagonists (atipamezole and yohimbine) and MOR antagonists (naloxone and naltrexone) produced rightward shifts in mitragynine discrimination dose-effect function and Aα 2 R agonists lofexidine and clonidine produced leftward shifts. In the mitragynine trained rats, Aα 2 R agonists also produced leftward shifts in discrimination dose-effect functions for morphine and fentanyl. In a separate rat cohort trained to discriminate 3.2 mg/kg i.p. morphine from vehicle, naltrexone produced a rightward shift, but neither an Aα 2 R agonist or antagonist affected morphine discrimination. In a hypothermia assay, both lofexidine and clonidine produced marked effects antagonized by yohimbine. Mitragynine did not produce hypothermia. Together, these data demonstrate that mitragynine acts in vivo like an Aα 2 R agonist, although its failure to induce hypothermia or stimulate [35S]GTPγS binding in vitro , suggests that mitragynine maybe a low efficacy Aα 2 R agonist. [ABSTRACT FROM AUTHOR]

Mitragynine, an alkaloid found in Mitragyna speciosa (kratom), shows promise as a potential alternative to opioids owing to its distinctive indole alkaloid structure and its capacity for pain relief, alleviation of opioid withdrawal symptoms, and anti-inflammatory effects. Recently the intricate process of mitragynine biosynthesis from the precursor strictosidine was elucidated, providing insights into the complex pathways responsible for synthesizing this opioid compound and its related diastereomers. As the search continues for the authentic hydroxylase and methyltransferase crucial for mitragynine formation, leveraging enzymes from other species and exploiting enzyme promiscuity has facilitated heterologous mitragynine biosynthesis in microbes. This highlights the extraordinary flexibility of enzymes in generating a spectrum of variations and analogs of kratom opioids within alternative biological systems. [ABSTRACT FROM AUTHOR]

The phytochemical investigation of the stem barks of Voacanga africana resulted in the isolation of fifteen known monoterpenoid indole alkaloids (1 – 15). The structures of the alkaloids were determined by comparison of their physical and spectroscopic data with those reported in literature. Twelve of these metabolites (4 – 15) were previously unreported within the genus Voacanga , thus they can serve as chemotaxonomic markers for V. africana to differentiate between V. africana from other species of the genus Voacanga. The alkaloids 3-oxoconopharyngine (6), ervahainanmine (10), crassanine (14) and conolobine A (15) hold the potential to serve as chemical markers for distinguishing V. africana from other family species. Furthermore, compounds 3 , 6 , 10 , 12 showed potential antimicrobial activities against Candida albicans and Bacillus subtilis with MIC values of 6.25–12.50 μg/mL. [Display omitted] • A phytochemical investigation of Voacanga africana has been carried out. • Fifteen monoterpenoid indole alkaloids were identified from the stem barks of Voacanga africana. • Twelve compounds 4 – 15 were reported for the first time from the genus Voacanga. • Chemotaxonomic significance of these alkaloids was discussed. • Compounds 3 , 6 , 10 , 12 showed potential antimicrobial activities against Candida albicans and Bacillus subtilis. [ABSTRACT FROM AUTHOR]

A strain of Penicillium chrysogenum , isolated from a volcanic area, was subjected to chemical analysis, leading to the isolation of fifteen compounds. Six compounds were isolated for the first time from this species , including the benzophenone derivative 1 , pencillixanthone A (5), a pair of trichodimerol derivatives (7 , 8), 4-epipenicillone (9), and the small pyrone 14. Several of the compounds were tested for antimicrobial properties; among them, the secalonic acid derivative (5) had significant antibacterial activity against five test strains, while the trichodimerol derivatives (8 and 9) and the anthranilate derivative 15 were reported to be active against four strains (S. aureus, S. mutans, P. fluorescens, M. catarrhalis) for the first time. In addition, this is the first time that haenamindole's antibacterial activity has been reported. The chemotaxonomic significance of the isolated compounds is discussed. • Fifteen compounds isolated from Penicillium chrysogenum. • Six compounds isolated for the first time from species. • Two trichodimerol analogues possess antibiotic activity against four bacteria. [ABSTRACT FROM AUTHOR]

Strobilanthes cusia is a traditional Chinese medicinal herb containing indole alkaloids, key bioactive components responsible for its pharmacological effects. However, there has been limited research regarding S. cusia compositional impact on antimicrobial properties. This study centered around the hydrolysis and oxidative condensation reactions of indican, aiming to investigate the influence of its intermediate, indoxyl, on pathogenic bacteria growth and biofilm formation. A notable inhibitory effect of indoxyl on Staphylococcus aureus biofilm formation was found. High-performance liquid chromatography and transmission electron microscopy confirmed that indoxyl disrupted the membrane structure of biofilm cells, causing a disturbance in cellular redox balance. These findings suggest that the oxidative reaction of indoxyl within cells could be a prominent factor affecting cell viability. Simultaneously, a portion of indoxyl oxidized externally to form indigo, which did not affect intracellular activities but rather disrupted the biofilm structure. The concept of "compositional changes" enriches the understanding of antimicrobial properties of S. cusia , offering novel approaches for effectively inhibiting pathogenic microorganisms. [Display omitted] • The hydrolysis and condensation of indican induced composition changes. • Composition changes induced multi-target inhibitory effects on biofilm. • Indoxyl entered into cells and altered intracellular redox status. • Indigo affected cell-to-cell adhesion, disrupting biofilm structure. • Composition changes could improve anti-biofilm ability of S. cusia biomass. [ABSTRACT FROM AUTHOR]

Kratom is a herbal substance belonging to the group of new psychoactive substances. It contains psychoactive indole alkaloids mitragynine and 7-hydroxymitragynine. At low doses, they act as psychostimulants and at higher doses they mediate an opioid-like effect. The increasing misuse of kratom requires the development of analytical methods that will accurately and reliably identify and quantify its psychoactive alkaloids in biological samples. Therefore, the development of effective, precise, and reliable green analytical methods that are easy to implement in practice is of great importance. On-line combination of capillary zone electrophoresis with tandem mass spectrometry (CZE-MS/MS) seems to be a promising solution. We present a novel green approach based on capillary zone electrophoresis – tandem mass spectrometry (CZE-MS/MS) method with on-line dynamic pH junction sample pretreatment to identify and determine mitragynine and 7-hydroxymitragynine in urine samples. The separation was performed in a background electrolyte composed of 100 mM formic acid (pH 2.39). The dynamic pH junction was ensured by injection of a short plug of 12.5 % NH 4 OH before the sample. Under optimal conditions, the developed method was validated and parameters such as linearity (r2 > 0.99), precision (2.2–8.7 %), accuracy (89.2–102.5 %) or stability of the sample (86.6–114.7 %) met the defined FDA guideline criteria (%RSD and %RE values where within ±15 %). Introduction of a simple in-capillary preconcentration strategy based on dynamic pH junction enabled significant improvement in analytical signal intensity and also the applicability of the method. Applying the presented approach, high sensitivity was achieved as indicated by limit of detection values, which were 0.5 ng mL−1 and 2 ng mL−1 for mitragynine and 7-hydroxymitragynine, respectively. Greenness of the proposed approach was confirmed by the AGREE metrics (score 0.63). The application potential of the developed method was successfully verified using blinded urine model samples. For the first time a fully validated CZE-MS/MS method for kratom alkaloids determination was introduced. The presented novel method is a cheaper and more ecological alternative to conventionally used chromatographic techniques what was clearly confirmed by its greenness evaluation and comparison with previously published liquid chromatography (LC) approaches. In-capillary sample pretreatment (dynamic pH junction) has been demonstrated to be an effective and fast tool in bioanalysis, minimizing the number of pretreatment steps and the manipulation with the sample. Moreover, LOD values comparable to those obtained by LC methods were recorded. High potential for the implementation of this approach into the toxicology environment in the near future is expected. [Display omitted] • The first validated CZE-MS/MS method for the determination of mitragynine and 7-hydroxymitragynine in biological samples. • Effective in-capillary sample pretreatment based on dynamic pH junction. • a suitable tool to prove the presence of kratom alkaloids in urine for toxicological purposes. • Green analytical method in toxicology. [ABSTRACT FROM AUTHOR]

• 24 novel monoterpenoid indole alkaloid (MIA)-like analogs were designed and prepared by biomimetic synthetic strategy. • Compound 17 displayed approximately 47-fold stronger diphenolase inhibitory activity than that of loganetin. • Molecular docking study indicated that compound 17 might exert inhibitory activity by binding to the key amino acid residues (His 85 and His 263) at the tyrosinase active site. A series of novel monoterpenoid indole alkaloid (MIA)-like analogs (1 – 24) were synthesized by using a biomimetic synthetic strategy and combinatorial chemistry. The tyrosinase inhibitory activities and antioxidant properties of these compounds were assessed through tyrosinase inhibition assay, DPPH and ABTS free radicals scavenging assays, respectively. The results showed that most synthesized compounds (2, 4 – 8, 10 – 12, 14 – 17, 19) exhibited significant inhibitory activities against both monophenolase and diphenolase. In particular, compound 14 , with an IC 50 value of 0.18 ± 0.02 mM, displayed approximately 72-fold stronger monophenolase inhibitory activity than that of loganetin with an IC 50 value of 12.76 ± 1.00 mM. Similarly, compound 17 exhibited the best diphenolase inhibitory activity (IC 50 , 0.30 ± 0.09 mM), which was approximately 47 times higher than that of loganetin (IC 50 , 14.05 ± 0.47 mM). Additionally, six compounds (3, 13 – 17) showed significant in vitro antioxidant activities. Compound 17 exhibited the most promising ABTS radical scavenging activity with an IC 50 value of 2.90 ± 0.07 μ M, while compound 15 exhibited the highest DPPH free radical scavenging capacity with an IC 50 value of 17.59 ± 0.21 μ M. The structure-activity relationships analysis revealed that the substituents at C-5 and C-11 in the tryptamine moiety might significantly impact antioxidant activity. Furthermore, the detailed interactions and binding modes of the most potent derivative toward tyrosinase were elucidated by a molecular docking study, which indicated that 14 and 17 might exert their inhibitory effects by binding to key amino acid residues (His 85 and His 263) at the tyrosinase active site. [ABSTRACT FROM AUTHOR]

Ophiorrhiza mungos (O. mungos) , a significant medicinal plant belonging to the Rubiaceae family, is native to the Indian subcontinent and predominantly found in countries like India, Nepal, Bhutan, Bangladesh, and Sri Lanka. Recently, it has gained recognition as a promising alternative source of anticancer compounds. The presence of camptothecin (CPT), a modified monoterpene indole alkaloid, in notable quantities has sparked interest in researching O. mungos. This present study is focused on enhancing the synthesis of CPT through in vitro shoot growth of O. mungos using a half-strength Murashige and Skoog growth medium supplemented with specific precursors. Among the precursors tested, L-tryptophan and geraniol exhibited the most significant increase in CPT levels, with a 33 % enhancement compared to the untreated shoots. The researchers employed response surface methodology to explore the combined effect of these precursors on CPT production. In the study, in vitro plantlets were treated with L-tryptophan and geraniol at a concentration of 1.5 mM each, resulting in the highest CPT levels ranging from 1658.52 to 1747.63 µg/g. The validity of the experimental approach was confirmed by the close agreement between the experimental value and the predicted value of 1702.00 µg/g, demonstrating a 99.3 % validity of the model. This study underscores the significance of utilizing a combination of precursors to enhance the production of secondary metabolites, specifically CPT, in O. mungos shoot cultures. Furthermore, it identifies L-tryptophan and geraniol, along with their respective doses, as effective precursors for improved CPT synthesis. Notably, this research employed response surface methodology to investigate the potential of L-tryptophan and geraniol as precursors for CPT production in the in vitro shoot growth of O. mungos , marking a significant contribution in this field of study. Top of Form [Display omitted] • Precursor feeding of Ophiorrhiza mungos in vitro shoots to enhance camptothecin production. • The potential of L-tryptophan and geraniol as precursors for camptothecin production. • L-tryptophan and geraniol at a concentration of 1.5 mM each, for increased camptothecin levels in Ophiorrhiza mungos in vitro shoots. [ABSTRACT FROM AUTHOR]

New psychoactive substances (NPS) are of public health concern due to their sporadic proliferation and the dearth of information on toxicity when consumed. In addition to seized data from forensic and toxicology reporting, wastewater analysis serves as a complimentary tool for NPS surveillance. A method to detect 71 NPS by simple filtration followed by liquid-chromatography tandem mass spectrometry was developed to detect multiclass NPS consisting of arylcyclohexylamines, designer benzodiazepines, synthetic cannabinoids, synthetic opioids, phenethylamines, synthetic cathinones, tryptamines, and indole alkaloids. In this work, the influential factors for electrospray ionisation were identified and optimised using the fractional factorial design and face-centred central composite design, respectively. The filtration loss during sample clean-up was assessed for all compounds. The final method was validated and applied to wastewater collected from a music festival held in Queensland in 2022. The validated method had linearity between 0.5 ng L−1 and 5000 ng L−1, the limit of quantification (LOQ) ranges from 0.6 ng L−1 to 70 ng L−1, precision within ±20 %, accuracy ranges from 70 % to 120 %, and matrix effect ranges from soft (0 %–20 %) to medium (20 %–50 %) for the majority of the compounds. NPS detected in the festival were 2-fluorodeschloroketamine, 7-hydroxymitragynine, mitragynine, N,N -dimethylpentylone, pentylone, phenibut, and O- desmethyltramadol. Systematic electrospray ionisation optimisation using the design of experiment for a large method is practical and provides in-depth chemical information on studied compounds. The optimised method demonstrated the applicability of analysing samples collected from a festival in this work. [Display omitted] • A high throughput method was developed for 71 new psychoactive substances. • Important variables for optimisation were temperature, ion source gas, and ion source voltage. • Seven compounds were detected in samples collected from a festival. [ABSTRACT FROM AUTHOR]

Seven previously undescribed compounds, including four diketomorpholine alkaloids (1 ‒ 4), one indole diketopiperazine alkaloid (9), one chromone (10), and one benzoic acid derivative (13), and nine known compounds (5 – 8 , 11 , 12 , and 14 – 16) were isolated from two different fungal sources. Nine of these metabolites (1 – 9) were obtained from a seagrass-derived Aspergillus alabamensis SYSU-6778, while the others were obtained from a mixed culture of A. alabamensis SYSU-6778 and a co-isolated fungus A. fumigatiaffinis SYSU-6786. The chemical structures of the compounds were deduced via spectroscopic techniques (including HRESIMS, 1D and 2D NMR), chemical reactions, and ECD calculations. It is worth noting that compound 10 was identified as a defensive secondary metabolite of strain SYSU-6786, produced through the induction of compound 8 under co-culture conditions. Compounds 3 and 4 possessed a naturally rare isotryptophan core. Moreover, compounds 1 and 2 exhibited potent inhibitory activities against fish pathogenic bacterium Edwardsiella ictalurid, with minimum inhibitory concentration values of 10.0 μg/mL for both compounds. [Display omitted] • Sixteen metabolites (1 – 16) were purified from two seagrass-derived Aspergillus strains. • Compounds 10 and 13 were induced by compound 8 under co-culture conditions. • Compound 10 was identified as defensive specialized metabolite of A. fumigatiaffinis. • Compounds 1 and 2 exhibited antibacterial activity against fish pathogens. [ABSTRACT FROM AUTHOR]

Camptothecin (CPT) is a monoterpenoid indole alkaloid with a wide spectrum of anticancer activity. However, its application is hindered by poor solubility, lack of targeting specificity, and severe side effects. Structural derivatization of CPT and the development of suitable drug delivery systems are potential strategies for addressing these issues. In this study, we discovered that the protein Cytochrome P450 Family 1 Subfamily A Member 1 (CYP1A1) from Homo sapiens catalyzes CPT to yield 9-hydroxycamptothecin (9-HCPT), which exhibits increased water solubility and cytotoxicity. We then created a RNA-protein complex based drug delivery system with enzyme and pH responsiveness and improved the targeting and stability of the nanomedicine through protein module assembly. The subcellular localization of nanoparticles can be visualized using fluorescent RNA probes. Our results not only identified the protein CYP1A1 responsible for the structural derivatization of CPT to synthesize 9-HCPT but also offered potential strategies for enhancing the utilization of silk-based drug delivery systems in tumor therapy. We discovered that the CYP1A1 from liver cells could catalyze the biosynthesis of 9-hydroxycamptothecin (9-HCPT) from camptothecin (CPT). 9-HCPT exhibited excellent anti-proliferation activity toward different cancer cells, which could further be enhanced by the designing and utilization of a nanoparticle-based drug delivery system. [Display omitted] [ABSTRACT FROM AUTHOR]

Plants of the Strychnos genus, which include about 200 species, are used for multiple traditional purposes as hunting poison, for example, and have shown interesting pharmacological properties, especially curarizing and tetanizing, but also against malaria. Many monoterpene indole alkaloids have already been isolated and identified. Among them, there is strychnine, a famous alkaloid that can cause death by asphyxiation. Investigate alkaloidic molecular diversity from Strychnos genus using molecular networking technique and study the Strychnos genus from a chemotaxonomic point of view. Twenty-eight different species and different plant parts were ground into powder using a grinder. The methanolic extracts were carried out using a pressurized solvent extraction and the alkaloid extract was performed manually with a separating funnel. The extracts were analyzed by HPLC-ESI(+)-Q/TOF. The data were processed using MZmine 2 software and the molecular network was generated on the GNPS platform. The study of the generated molecular network allowed the detection of various alkaloids. Among these is the famous strychnine which has been detected in 7 new Strychnos species not yet described as strychnine producers. This identification was investigated using orthogonal approaches, namely TLC, NMR, HPLC-UV and UHPLC-ESI(+)-Q/TOF analyses. The LOD by HPLC-UV of strychnine was also determined. Further analyses allowed to confirm the presence of strychnine in S. densiflora trunk barks but also to show the presence of strychnine with high probability in the trunk barks of S. camptoneura , S. congolana , S. boonei , and S. tchibangensis , and in the leaves of S. usambarensis. About the trunk barks of S. tricalyisoides , the probability of a strychnine content remains low. This work exemplified the efficiency of molecular networking in identifying known metabolites (major and minor alkaloids) involved in the chemotaxonomic study of plants from Strychnos genus. [Display omitted] • The pantropical plants of Strychnos genus contain biologically active monoterpene indole alkaloids. • The Leeuwenberg's classification of Strychnos into 12 sections is questioned. • 44 crude extracts from 27 Strychnos species were studied by HPLC-ESI(+)-Q/TOF and by molecular networking analysis. • Strychnine was identified in 3 well-known and 1 new species, and detected in 5 additional species by HPLC-MS/MS analysis. • This study is a contribution to the chemotaxonomic understanding of the species belonging to Strychnos genus. [ABSTRACT FROM AUTHOR]

Harmaline is an indole alkaloid with demonstrated phytotoxicity and recognized pharmacological applications. However, no information is available concerning its mode of action on plant metabolism. Therefore, the present work evaluated bioherbicide mode of action of harmaline on plant metabolism of Arabidopsis thaliana (L.) Heynh. Harmaline induced a strong inhibitory activity on root growth of treated seedlings, reaching IC 50 and IC 80 values of 14 and 29 μM, respectively. Treated roots were shorter and thicker than control and were characterized by a shorter root meristem size and an increase of root hairs production. Harmaline induced ultrastructural changes such as increment of cell wall thickness, higher density and condensation of mitochondria and vacuolization, appearance of cell wall deposits, increment of Golgi secretory activity and higher percentage of aberrant nuclei. The ethylene inhibitor AgNO 3 reversed high root hair appearance and increment of root thickness, and pTCSn::GFP transgenic line showed fluorescence cytokinin signal in stele zone after harmaline treatment that was absent in control, whereas the auxin signal in the transgenic line DR5 was significantly reduced by the treatment. All these results suggest that the mode of action of harmaline could be involving auxin, ethylene and cytokinin synergic/antagonistic action. • Harmaline showed phytotoxic potential on Arabidopsis thaliana seedlings. • Harmaline induced ultrastructural changes on Arabidopsis thaliana roots. • Cytokinin, auxin and ethylene could be involved in harmaline mode of action. [ABSTRACT FROM AUTHOR]

In this study, a functionalized covalent-organic framework (COF) was first synthesized using porphyrin as the fabrication unit and showed an edge-curled, petal-like and well-ordered structure. The synthesized COF was then introduced to prepare porous organic polymer monolithic materials (POPMs). Two composite POPM/COF monolithic materials with rod shapes, referred to as sorbent A and sorbent B, were prepared in stainless steel tubes using different monomers. Sorbents A and B exhibited relatively uniform porous structures and enhanced specific surface areas of 153.14 m2/g and 80.01 m2/g, respectively. The prepared composite monoliths were used as in-tube solid-phase extraction (SPE) sorbents combined with HPLC for the on-line extraction and quantitative analytical systems. Indole alkaloids (from Catharanthus roseus G. Don and Uncaria rhynchophylla (Miq.) Miq. Ex Havil.) contained in mouse plasma were extracted and quantitatively analyzed using the online system. The two composite multifunctional monoliths showed excellent clean-up ability for complex biological matrices, as well as superior selectivity for target indole alkaloids. Method validation showed that the RSD values of the repeatability (n =6) were ≤ 3.46%, and the accuracy expressed by the spiked recoveries was in the ranges of 99.38%–100.91% and 96.39%–103.50% for vinca alkaloids and Uncaria alkaloids, respectively. Furthermore, sorbents A and B exhibited strong reusability, with RSD values ≤ 5.32%, which were based on the peak area of the corresponding alkaloids with more than 100 injections. These results indicate that the composite POPM/COF rod-shaped monoliths are promising media as SPE sorbents for extracting trace compounds in complex biological samples. [Display omitted] • Edge-curled petals-like COF was synthesized using porphyrin as the fabrication unit. • In-tube monolithic POMP/COF composite SPE sorbents with rod-shape were fabricated. • The in-tube sorbents were used to extract hence indole alkaloids from complex samples. • The two homemade sorbents show strong reusability of more than 100 times. [ABSTRACT FROM AUTHOR]

Indole alkaloid camalexin has potential medicinal properties such as suppressing the viability of leukemic but not normal cells. Camalexin is not produced in plants and an external factor is required to activate its biosynthesis. In this work, we stimulated camalexin biosynthesis in Arabidopsis calli by blocking one of repressors of the jasmonate pathway, the jasmonate ZIM-domain protein 1 (JAZ1) by using amiRNA targeting JAZ1 gene transcripts. Inhibition of the JAZ1 gene led to an increase in camalexin content from trace amounts in control culture to 9 µg/g DW in the jaz1 line without affecting growth. In addition, JAZ1 silencing enhanced tolerance to cold stress with simultaneous increasing camalexin content up to 30 µg/g DW. Real-time quantitative PCR determination of marker gene expression showed that effects caused by the JAZ1 silencing might be realized through crosslinking JA, ROS, and abscisic acid signaling pathways. Thus, targeting the distal components of signaling pathways can be suggested as a tool for bioengineering of secondary metabolism, along with standard techniques for targeting biosynthetic genes or genes encoding transcription factors. • JAZ1 inhibition increased camalexin content from trace amounts up to 9 µg/g DW. • Cold and salt treatments increased camalexin content in jaz1 calli up to 30 µg/g DW. • Inhibition of JAZ1 stimulates biosynthesis of camalexin without impairing cell growth. [ABSTRACT FROM AUTHOR]

The genus Rauvolfia belongs to the family Apocyanaceae, and is native to the tropical countries of the world. Six species of Rauvolfia have been reported from India, however, only two species viz. R. serpentina and R. tetraphylla grow in the upper Gangetic plains. The monoterpenoid indole alkaloids reserpine and ajmalicine are the major phytochemicals reported from the roots of the above plants and are well known for their potential antihypertensive activity. Presently, R. serpentina has become critically endangered due to its overexploitation. Therefore, this study was designed to develop a validated High Performance Thin Layer Chromatographic densitometric method for determination of reserpine and ajmalicine in R. serpentina and R. tetraphylla in different seasons. Plant materials were collected in March, June, September and December to determine the optimal harvesting time. The densitometric method was validated in terms of instrument precision, range, linearity, specificity, limit of detection and limit of quantitation. Reproducibility of the peak of reserpine and ajmalicine was achieved at Rf 0.56, and 0.79 respectively using optimised mobile phase toluene– ethyl acetate-diethyl amine (7:2:0.6 v/v/v). Our study concluded that maximum level of ajmalicine was found in March while that of reserpine was observed in September. Harvesting of R. tetraphylla at the optimal season may reduce the overexploitation of the endangered species R. serpentina. [Display omitted] • HPTLC is an important tool for seasonal variation study of phytochemicals. • Reserpine and ajmalicine are potential antihypertensive alkaloids of Rauvolfia. • R. serpentina and R. tetraphylla were collected in four seasons from northern India. • Ajmalicine found maximum in March in R. serpentina and R. tetraphylla. • Reserpine found maximum in September in aforesaid species. [ABSTRACT FROM AUTHOR]

The presence of phytotoxins in plants constitutes a health risk for herbivores, particularly on ruminants who accidently consume them. Among the adverse effects produced by these are reproductive alterations, represented by abortion, infertility, and morphological alterations in neonates, which are frequently attributed to other causes. While in some cases the plants that contain such metabolites are known, other times they are not, leading to alterations that are difficult to treat considering that their toxicodynamics are unknown. The objective of this documentary research is to provide information on how metabolites such as phytoestrogens, L-mimosine, labdane diterpenoids - isocupressic acid, quinolizidine alkaloids and piperidine swainsonine, anabasine, coniine and associated alkaloids, among others, exert their action in the animal organism and the effects they produce. [Display omitted] • Corrected spelling and reviewed the proper classifications used for all compounds. • All metabolites and scientific names of the plants were reviewed. • Isocupressic acid. labdane resin acid, agathic acid, coniine were corrected. [ABSTRACT FROM AUTHOR]