Search

Phytochemical investigations of the twig and leaf extracts of Uvaria dac Pierre ex Finet & Gagnep. resulted in the isolation and identification of five new highly oxygenated cyclohexenes, uvaridacols M − Q (1 – 3 , 5 , and 6), and six known compounds (4 and 7 – 11). All new structures were elucidated by spectroscopic methods and HRESITOFMS data. The absolute configuration of 1 , 5 , and 6 was confirmed by single X-ray diffraction analysis with Cu Kα radiation. In contrast, other compounds were established by comparing their specific rotation and ECD spectra with those of known compounds. Some of the isolated compounds with sufficient quantity were evaluated for their α-glucosidase inhibitory activity. Of these, (−)-1,6-desoxypipoxide (10) showed α-glucosidase inhibitory activity with an IC 50 value of 28.6 μM. The in silico molecular docking of active compounds was also studied. Phytochemical investigations of the twig and leaf extracts of Uvaria dac Pierre ex Finet & Gagnep. resulted in the isolation and identification of five new highly oxygenated cyclohexenes and six known compounds. Some of the isolated compounds with sufficient quantity were evaluated for their α-glucosidase inhibitory activity. Of these, (−)-1,6-desoxypipoxide (10) showed α-glucosidase inhibitory activities with an IC 50 value of 28.6 μM. [Display omitted] • Five new oxygenated cyclohexenes were isolated from Uvaria dac. • The absolute configuration of uvaridacol M, P, Q were confirmed by single X-ray diffraction analysis with Cu Kα radiation. • Oxygenated cyclohexenes containing a cinnamoyl moiety, such as uvaridacols N and P first reported here. • 1,6-Desoxypipoxide showed α -glucosidase inhibitory activity. • 1,6-Desoxypipoxide was docked into α -glucosidase (PDB ID: 2QMJ) in silico molecular docking. [ABSTRACT FROM AUTHOR]

Four new meroterpenoids, namely nivalones C F (1 – 4), along with a known meroterpenoid, cannabiorcicyclolic acid (5), were isolated from the branches and leaves of Rhododendron nivale. The chemical structures of compounds 1 – 4 were elucidated through comprehensive spectroscopic analyses, including NMR, UV–Vis, IR, ECD spectroscopy, as well as HR-ESI-MS. The isolated compounds were evaluated for their anti-inflammatory and neuroprotective properties. The inhibitory activity of compound 5 against lipopolysaccharide (LPS)-induced nitric oxide (NO) production was initially demonstrated, showcasing an IC 50 value of 21.1 μM. Additionally, both compounds 2 and 5 displayed a notable effect on the viability of H 2 O 2 -damaged SH-SY5Y cells, indicating their significant neuroprotection effects. Four new meroterpenoids 1 – 4 (nivalones C F) and a known meroterpenoid 5 with good anti-inflammatory and neuroprotective effects were isolated from Rhododendron nivale. [Display omitted] [ABSTRACT FROM AUTHOR]

Diterpenoids occupy an important slot of the natural products diversity space with wide ranges of bioactivities and complex structures, providing potential applications for the development of therapeutics. In this study, we reported four new abietane-type diterpenoids viroxocin B-E (1–4), a new totarane-type diterpenoid viroxocin F (5), and a new sempervirane-type diterpenoid viroxocin G (6) along with four known compounds (7 – 10), isolated and identified from a widely used Traditional Chinese Medicine, Isodon serra (I. serra). Their structures were established by spectroscopic data analysis, experimental and calculated electronic circular dichroism (ECD) data, as well as X-ray diffraction analysis. Compounds 2 , 5 , 7 , 8 and 10 exhibited promising anti-inflammatory activities in lipopolysaccharide (LPS)-induced RAW 267.4 cells, and their inhibition rates on NO production were more than 60% at 10 μM. Compound 7 showed cytotoxicity against human renal cell carcinoma 769P at 20 μM, the inhibition rate was 52.66%. [Display omitted] [ABSTRACT FROM AUTHOR]

Three Stemona alkaloids named stemotuberines A–C (1 – 3) with unique C 17 N frameworks, presumably formed by elimination of the C-11–C-15 lactone ring of the stichoneurine skeleton, were isolated from the roots of Stemona tuberosa. Their structures were elucidated by spectroscopic analysis, X-ray diffraction, and computational methods. Compounds 2 and 3 showed inhibition (IC 50 values of 37.1 and 23.2 μM, respectively) against LPS-induced nitric oxide production in RAW 264.7 cells. In addition, concern was expressed about the reported plant origin (S. sessilifolia) of the recently described alkaloids tuberostemonols O–R (4–7), which should be S. tuberosa. NMR calculations indicated structural misassignment of these compounds except for 6. Isolation of tuberostemonol P (5) from our material of S. tuberosa allowed for a close examination of the spectroscopic data leading to the revised structure 5a. Tuberostemonol R (7) was found to have identical 1H and 13C NMR data to the well-known alkaloid croomine, and therefore its structure including relative stereochemistry must be revised as 7a. [Display omitted] • Three previously undescribed Stemona alkaloids were isolated from Stemona tuberosa. • Compounds 1 – 3 possess unprecedented C 17 N skeletons. • Nitric oxide inhibitory activities of isolated compounds were evaluated. • Putative structures of tuberostemonols P and R were revised. [ABSTRACT FROM AUTHOR]

Eleven new highly oxygenated eremophilane-type sesquiterpenoids were isolated from the whole plant of Synotis solidaginea , including two pairs of C-8 S / R epimers. The structures of the new compounds were elucidated on the basis of detailed spectroscopic analysis and the absolute configurations of 1 and 9 were confirmed by single-crystal X-ray crystallography using Cu K α radiation. All the isolates were tested for the inhibition of LPS-stimulated NO production in macrophage-like mouse monocytic leukemia RAW264.7 cells. Compound 1 exhibited weak inhibitory effects with an IC 50 of 71.2 μM. [Display omitted] [ABSTRACT FROM AUTHOR]

Six previously undescribed diterpenoid glucosides, along with four known compounds, were isolated from the aerial parts of Sigesbeckia glabrescens. The structures and absolute configurations of undescribed compounds were elucidated using extensive spectroscopic techniques, ECD calculations and chemical methods. Compounds 1 and 8 exhibited anti-inflammatory activity against LPS-induced NO production in RAW 264.7 macrophages, with compound 8 demonstrating significant inhibitory activity compared to positive control minocycline, boasting an IC 50 value at 14.20 μM. [Display omitted] [ABSTRACT FROM AUTHOR]

Three new xanthone derivatives irpexols A-C (1 – 3) and five known xanthones including three dimeric ones were successfully isolated from Irpex laceratus A878, an endophytic fungus of the family Irpicaceae from the medicinal plant Pogostemon cablin (Blanco) Bentham (Lamiaceae). The structures of these compounds were elucidated by extensive spectroscopic analyses including ultraviolet-visible spectroscopy (UV), infrared spectroscopy (IR), mass spectrometry (MS), and nuclear magnetic resonance (NMR). All of the three new compounds (1 – 3) share a de-aromatic and highly‑oxygenated xanthone skeleton. In addition, the cytotoxic activity of compounds 1 – 8 were evaluated against SF-268, MCF-7, HepG2, and A549 tumor cell lines. The results revealed that compound 6 showed moderate cytotoxic activity with the IC 50 values ranging from 24.83 to 45.46 μM, while the IC 50 values of the positive control adriamycin was ranging from 1.11 to 1.44 μM. [Display omitted] [ABSTRACT FROM AUTHOR]

Five new B- seco -limonoids, namely toonanoronoids A-E (1 – 5), in conjunction with three previously reported compounds, were isolated from the EtOAc extract of the twigs and leaves of Toona ciliata var. yunnanensis. Their structures were elucidated through comprehensive spectroscopic and X-ray crystallographic analysis. The cytotoxic activities of new compounds against five human tumor cell lines (HL-60, SMMC-7721, A549, MCF-7, and SW480) were screened, Compounds 4 and 5 exerted inhibition toward two tumor cell lines (HL-60, SW-480) with IC 50 values between 1.7 and 5.9 μM. [Display omitted] [ABSTRACT FROM AUTHOR]

Three new indole alkaloid derivatives, fissindoalkas A-C (1 – 3) together with one known biogenetically related polysubstituted indole alkaloid (4) were isolated from the roots of Fissistigma oldhamii (Hemsl.) Merr. The structures of compounds 1 – 4 were elucidated using comprehensive spectroscopic methods. The inhibitory activities of compounds 1 – 4 against nitric oxide (NO) production induced by lipopolysaccharide (LPS) were evaluated in vitro using mouse macrophage RAW264.7 cells. Compounds 2 and 3 showed potent inhibitory activities on NO production with IC 50 values of 2.52 ± 0.18 and 2.33 ± 0.16 μM. These results indicate that the discovery of indole alkaloid derivatives, from the roots of F. oldhamii , which show significant anti-inflammatory properties, could be of great importance to the research and for the development of novel natural anti-inflammatory agents. [Display omitted] [ABSTRACT FROM AUTHOR]

Five unusual seco-nortriterpenoids, 3 β -hydroxy-20,21-seco-30-nortaraxastan-20,21-dioic acid (1), 3 β -hydroxy-20,21-seco-30-nortaraxastan-20-oic-21-oate (2), 3 β -hydroxy-20-oxo-21,22-seco-30-nortaraxastan-22-oic acid (3), 3 β -hydroxy-19-oxo-20,21-seco-29,30-nortaraxastan-21-oic acid (4) and 3 β -hydroxy-19-oxo-20,21-seco-19-norlupan-21-oic acid (5) were isolated and elucidated from the anti-inflammatory activity fraction of the ethanol extract of Cirsium setosum. The structures of these compounds were established through spectroscopic methods. Preliminary biological assays showed that compounds 1 – 5 had significant inhibitory effect on NO production on lipopolysaccharide-stimulated RAW 264.7 cells, and compound 1 showed the strongest anti-inflammatory activity. This type of ring-opening compound is the first seco-triterpenoid structure discovered from the genus of Cirsium. [Display omitted] [ABSTRACT FROM AUTHOR]

Angiotensin I-converting enzyme (ACE) inhibition is currently a common method for the treatment and control of hypertension. In this study, four new (1–4) and one known (5) cycloartane triterpenoids were isolated from the leaves of Swietenia macrophylla by chromatographic techniques and identified by their spectroscopic data and a comprehensive comparison of published data. The triterpenoids were evaluated for their ACE inhibitory potential using in vitro inhibition assays and in silico methods. The inhibition assay and enzyme kinetics results showed that the most active triterpenoid, compound 4 , inhibited ACE in a mixed-type manner with an IC 50 value of 57.7 ± 6.07 μM. Computer simulations revealed that compound 4 reduces the catalytic efficiency of ACE by competitive insertion into the active pocket blocking the substrate, and the binding activity occurs mainly through hydrogen bonds and hydrophobic interactions. The study showed that S. macrophylla can be a source of bioactive material and the ACE inhibitory triterpenoid could be a potential antihypertensive agent. [Display omitted] • Four new cycloartane triterpenoids were isolated from Swietenia macrophylla. • 3β,16β-dihydroxy-29-norcycloartan-24-one (4) inhibited ACE in a mixed-type manner. • Hydrogenation at C-16 and substitution by the carbonyl group at C-24 enhanced the ACE inhibitory activity of the triterpenoids. • Computational simulation analyses showed that hydrogen bonds were the major binding forces. [ABSTRACT FROM AUTHOR]

In this research, five new indolequinazoline alkaloids (1 – 5), along with six known indolequinazoline alkaloids (6 – 11) were obtained from the fruits of Tetradium ruticarpum. Their structures were elucidated through comprehensive spectroscopic data of 1D and 2D NMR, HRESIMS and ECD spectra. Additionally, all isolates were assayed for their SIRT1 inhibitory activities in vitro and compounds 2 , 7 , 10 and 11 exhibited activities with IC 50 values ranged from 43.16 to 118.35 μM. Eleven indolequinazoline alkaloids, including five undescribed compounds, were isolated from the fruits of Tetradium ruticarpum and their SIRT1 inhibitory activities were assessed. [Display omitted] [ABSTRACT FROM AUTHOR]

Aspercitrininone A (1), a novel polyketide featuring an unprecedented tetracyclic 6/6/6/5 spiral skeleton, was obtained from the rice fermentation cultures of the fungus Aspergillus cristatus together with five known compounds (2 – 6). Their structures were determined by HRESIMS data, 1D and 2D NMR spectroscopic analysis, and electronic circular dichroism (ECD) calculations. Aspercitrininone A was revealed as a new type of C/D cycle spiral structure and an unusual addition product of o-quinoid form citrinin with 2-methylterrefuranone. Compounds 1 , 4 , and 5 exhibited potent antibacterial activities with minimal inhibitory concentration (MIC) values from 13.2 to 67.3 μg/mL against four strains of human pathogenic bacteria in vitro. [Display omitted] • A novel polyketide aspercitrininone A was isolated from rice cultures of Aspergillus cristatus. • Aspercitrininone A possessed an unprecedented tetracyclic 6/6/6/5 spiral skeleton. • It could be formed by o-quinoid form citrinin with 2-methylterrefuranone through Michael addition reaction. • Aspercitrininone A exhibited antibacterial activities. [ABSTRACT FROM AUTHOR]

As our ongoing searching for the bioactive natural terpenoids, nine ent -kauranoids (1 – 9), including three previously undescribed ones (1 , 2 , and 9), were isolated from the aerial parts of Isodon amethystoides. Their structures were elucidated on the basis of spectroscopic data analysis, including NMR, MS, and ECD. Compounds 1 and 2 were a pair of tautomeric compounds, which was confirmed by the HPLC analysis and low temperature NMR testing. The underlying mechanism of the tautomer was proposed as an intramolecular S N 2 reaction, which was explained by quantum chemical calculation. The HOMO-LUMO gap and the free energy revealed the spontaneous of the tautomeric of the 1 and 2. Additionally, the similar phenomena were also found in the two groups of known compounds 3 and 4 and 6 and 7 , respectively. Apart from the tautomer, compounds 3 and 4 can be hydrolyzed into 5 through ester hydrolysis in CDCl 3 , while compounds 6 , 7 can be hydrolyzed into 8 through ester hydrolysis. These phenomena were also confirmed through HPLC analysis and low temperature nuclear magnetic resonance tests and the mechanism was studied using quantum chemical calculation. [Display omitted] [ABSTRACT FROM AUTHOR]

Drynaria quercifolia is an epiphytic fern distributed all over Bangladesh with traditional use in treating neurological disorders and other ailments. Although several pharmacological activities of D. quercifolia have been investigated, the neuroprotective potential of this plant is still unexplored. In this study, we evaluated the in vitro anticholinesterase and antioxidant activities of D. quercifolia and the neuroprotective effect in scopolamine-induced memory-impaired mouse model. The crude methanol extract (DCM) of the plant was fractionated to prepare n-hexane (DHF), chloroform (DCF), ethyl acetate (DEF), and aqueous (DAF) factions. All the fractions were evaluated for anticholinesterase activity by modified Ellman's method and the antioxidant activity by several in vitro assays such as DPPH and hydroxyl free radicals scavenging, reducing power, and inhibition of brain lipid peroxidation. The effect of the most active fractions (both DCF and DEF) on learning and memory was assessed in scopolamine-induced mouse model of memory-impairment by Morris water maze tasks. Biochemical assays were performed in brain tissue. The active compound was isolated and characterized by chromatographic, spectroscopic, and molecular docking methods. Phytochemical analysis demonstrated a high content of phenolic and flavonoid in DEF. In vitro studies revealed a strong antioxidant power of DEF and anticholinesterase activity of DCF. Both the DCF and DEF significantly (P˂0.05) reduced the escape latency time in the Morris's water maze tasks, and increased the time spent in the northeast quadrant in the probe trial. Biochemical data demonstrated that treatment with DCF and DEF at different doses significantly (P˂0.0001) inhibited acetylcholinesterase activity, restored GSH levels, and reduced MDA levels in the brain of scopolamine-induced memory-impaired mice, indicating the protective effect of D. quercifolia , possibly by acetylcholinesterase inhibition and oxidative stress prevention. Chromatographic methods of separation led to he isolation of catechin and protocatechuric acid from DEF and 3,4-dihydroxy benzoic acid from DCF. The structure of the compounds was determined by studies of their 1H-NMR spectra. Molecular docking as well as in vitro study suggests the anticholinesterase and antioxidant activity of the isolated compounds. Our study suggested that the extracts of D. quercifolia , due to anticholinesterase and antioxidant activity, ameliorate the scopolamine-induced memory impairment in mice and thus may represent therapeutics in the treatment of Alzheimer's disease. [Display omitted] • The chloroform and ethyl acetate fraction of Drynaria quercifolia rhizome exhibited considerable anticholinesterase and antioxidant activity in vitro. • Both the fractions significantly improved learning and memory in scopolamine-induced memory-impaired mice via cholinesterase & lipid peroxidation inhibition activity, and non-enzymes augmentation. • The predominant compounds were found to be 3, 4-dihydroxybenzoic acid in the chloroform fraction, and catechin & 2, 3, 4-trihydroxybenzoic acid in the ethylacetate fraction, which were responsible for both anticholinesterase and antioxidant activities as evidenced from in vitro and molecular docking studies. • These results support the traditional use of D. quercifolia in the neurological disorder and suggest that both the chloroform and ethyl acetate fraction of the plant may represent therapeutics in the prevention or treatment of AD. [ABSTRACT FROM AUTHOR]

Eleutherine bulbosa (Mill.) Urb. is a medicinal and edible plant with various benefits for humans and animals. In this work, four new phenolic constituents (1 – 4), along with six known phenolic compounds (5 – 10) were obtained from the red bulbs of E. bulbosa. Their structures with absolute configurations were characterized by extensive spectroscopic analysis, combined with HR-ESI-MS and quantum mechanical electronic circular dichroism (ECD). Compounds 1 and 2 are novel homologous and heterodimers, respectively, featuring an unusual spiro ring system. All isolated phenolic constituents were tested for their antibacterial effects. The results revealed four phenolic compounds 1–3 and 7 showed moderate antibacterial activity against Bacillus subtilis, Staphylococcus aureus a nd Escherichia coli with minimum inhibitory concentration (MIC) values ranging from 15.6 to 250.0 μg/mL. [Display omitted] • Ten phenolic constituents were isolated from the red bulbs of Eleutherine bulbosa. • Compounds 1 and 2 are novel homologous and heterodimers, respectively, featuring an unusual spiro ring system. • Four phenolic compounds 1–3 and 7 showed moderate antibacterial activity with MIC values ranging from 15.6 to 250.0 μg/mL. [ABSTRACT FROM AUTHOR]

Six new compounds, including two depsidones garciculendepsidones A and B (1 and 2), one prenylated xanthone garciculenxanthone (3) and three dimeric xanthones bigarciculenxanthones A–C (4 – 6), were isolated from the twigs and leaves of Garcinia esculenta Y. H. Li. Their structures were elucidated based on comprehensive analyses of spectral data, including HRESIMS, 1D and 2D NMR, and ECD calculation. All the isolates were tested for their cytotoxicity against five human cancer cell lines (myeloid leukemia HL-60, lung cancer A-549 cells, hepatocellular carcinoma SMMC-7721, breast cancer MDA-MB-231 and colon cancer SW480), among them, compounds 3 – 5 displayed cytotoxic potential, especially garciculenxanthone (3) had the lowest IC 50 value of 8.2 μm for lung cancer A-549 cells. [Display omitted] [ABSTRACT FROM AUTHOR]

Three new phenolic glycosides (1 – 3) and a new lignan glycoside (4), together with five known compounds (5 – 9) were isolated from the ethanol extract of the aerial part of Gaultheria leucocarpa var. yunnanensis (Franch.) T.Z.Hsu & R.C.Fang. Their structures were determined on the basis of spectroscopic techniques, experimental and calculated ECD spectra, acid hydrolysis, and enzymatic hydrolysis experiments. All the isolates were evaluated for their anti-inflammatory and antioxidant activities. Compounds 7 and 8 exhibited inhibitory effects against the LPS-induced production of NO with IC 50 of 63.71 and 10.66 μM, respectively, compared to L-NMMA having an IC 50 of 6.95 μM. Besides, compound 7 also represented significant DPPH radical scavenging activity with EC 50 of 18.75 μM, comparable with vitamin C (EC 50 = 15.77 μM). [Display omitted] • Four new (1 – 4) and five known (5 – 9) compounds were isolated from Gaultheria leucocarpa var. yunnanensis. • Compounds 7 and 8 exhibited moderate inhibition against LPS-induced NO production. • Compound 7 showed a comparable DPPH radical scavenging effect to vitamin C. [ABSTRACT FROM AUTHOR]

Three undescribed compounds (1 – 3), including two butenolides and one indol alkaloids. Together with twenty-one known compounds (4 – 24) were isolated and identified from Lepidium obtusum Basin. Their structures were elucidated by spectroscopic analysis and ECD calculations. The isolated compounds were tested for their antimicrobial, antioxidant, and anti-inflammatory activities. Among them, compounds 11 , 12 , 14 , 21 and 23 showed moderated antimicrobial activities against (Candida albicans , E. coli , Staphylococcus aureus). Compounds 11 , 12 , 14 , 15 , 17 and 18 exhibited potent antioxidant activities against ABTS and DPPH. Compound 1 exhibited moderated anti-inflammatory activities. Compounds 4 – 24 were isolated from this plant for the first time. [Display omitted] [ABSTRACT FROM AUTHOR]