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Guaianolide is a type of naturally occurring sesquiterpene lactone compounds that have attracted attention due to their diverse biological properties. In this work, a guaiane-type sesquiterpene lactone identified as deoxycynaropicrin (compound 1) was isolated and reported for the first time from the leaves of Centaurothamnus maximus with two known flavonoid derivatives namely luteolin 6-O-methyl ether (compound 2) and quercetin 3-methyl ether 5-O-glucopyranoside (compound 3). The cytotoxic activity of all the three compounds was evaluated against the THP-1 human leukemia cell lines. Moreover, flow cytometry was employed to explore the cell cycle arrest and apoptosis induction for the active compound. We found that compound 1 (deoxycynaropicrin) exerted the highest cytotoxicity while compounds 2 and 3 showed no activity. Cell cycle analysis showed that compound 1 arrested the cells’ population at the G2/M phase. Furthermore, THP-1 cells treated with compound 1 exhibited a marked increase in the apoptotic cells compared to the control. Overall, this study showed that deoxycynaropicrin induces cytotoxicity against human leukemia cell lines and provided an important insight into its potential therapeutic effects against leukemia cells.

Numerous studies highlighted the impact of natural products, particularly phytosterols, in wound healing while providing less expensive alternatives to chemically synthesized drugs, with less side effects. Centaurea pumilio L. (family Asteraceae) is a rare and endangered species of genus Centaurea with few reports concerning its chemistry. Our phytochemical investigation for the non-polar fraction of its aerial parts led to the isolation and identification of the new compound (6) identified as stigmast-1,5-dien-3-O-β-d-glucopyranoside along with five known sterols and triterpenes (1–5) identified as taraxasterol, β-sitosterol, stigmasterol, β-sitosterol glucoside, and stigmasterol-3-O-β-d-glucopyranoside. Structures of the isolated compounds have been characterized using 1D, 2D NMR, and mass spectral analyses. The cell viability and proliferative activity of the isolated compounds were evaluated using an MTT assay on cultured human primary umbilical vein endothelial cells (HUVEC). None of the compounds exhibited any sign of cytotoxicity. Nonetheless, compounds 5 and 6 moderately enhanced the HUVEC cell growth by 14 and 16%, respectively, at the maximal tested dose (50 µg/mL). As inhibition of glycogen synthase kinase 3-β (GSK3-β) enzyme is important to enhance the wound healing process; therefore, molecular docking was performed to understand the possible interactions between bioactive compounds 5 and 6 and GSK-3β binding pocket active amino acid residues. Both compounds were able to bind to the substrate‑binding site of GSK-3β and potentially interact with the key active site residues, forming strong π and hydrogen interactions with the catalytic site residues, revealing lower binding energy (−7.185 and −6.303 kcal/mol, respectively) than that of indirubin-3-monooxime (−5.303 kcal/mol); thereby representing strong natural replacements candidates for GSK-3β inhibitors.

The lack of any effective cure for the infectious COVID-19 disease has created a sense of urgency and motivated the search for effective antiviral drugs. Abyssomicins are actinomyces-derived spirotetronates polyketides antibiotics known for their promising antibacterial, antitumor, and antiviral activities. In this study, computational approaches were used to investigate the binding mechanism and the inhibitory ability of 38 abyssomicins against the main protease (M

Oxidative stress and chronic inflammation have a role in developing neurodegenerative diseases such as Parkinson's disease (PD) and inflammatory movement disorders such as rheumatoid arthritis that affect millions of populations. In searching for antioxidant and anti-inflammatory molecules from natural sources that can counteract neurodegenerative diseases and arthritis, the flavonoid-rich extract of

A new sesquiterpene lactone, 3β,10α-dihydroxy-10β-(hydroxymethyl)-8α-(4-hydroxymethacrylate)-1αH,5αH,6βH,7αH-guai-4(15), 11(13)-dien-6,12-olide (1), along with twenty-one known compounds, were identified from the aerial parts of Centaurothamnus maximus. The structures of the isolated compounds were elucidated on the basis of spectroscopic evidences and correlated with known compounds. Compounds (2, 3, 5‒13 and 15‒22) were identified from C. maximus for the first time. Antibacterial and antifungal activities of the isolated compounds were tested using the agar disc diffusion method. Compounds that demonstrated promising antimicrobial activity were evaluated for their minimum inhibitory concentration (MIC). The results showed that compounds 3 and 7 were the most effective antibacterial compounds against B. subtilis ATCC 6633, S. aureus ATCC 25923 and S. pyogenes ATCC 27736, with MIC estimates between 8 and 32 mg/mL. In addition, compound 2 exhibited the strongest antifungal activity against C. albicans ATCC 14243 and C. krusei ATCC 14243 with MIC 8 mg/mL. Twenty-two compounds were first isolated from Centaurothamnus maximus The structure of the new sesquiterpene lactone, thamnolide (1), was established. Antibacterial and antifungal activities were tested for the isolated compounds. Compounds 3 and 7 were the strongest antibacterial compounds whilst 2 exhibited the strongest antifungal activity.

Background Terrestrial mollusks are one of most important agricultural pests worldwide. Natural phytochemicals have an extended history as a source of pesticides. This study was planned to isolate molluscicidal active compounds from the stems of Adenium obesum. Results The benzene-soluble fraction of the hydroethanolic extract displayed the most potent molluscicidal activity against Monacha obstructa among different solvent fractions with a median lethal dose (LD50 ) of 4.91 µg g-1 body weight (bw). The bioactivity-guided chemical exploration of the benzene-soluble fraction led to the isolation of two known cardiac glycosides, cerberin and neriifolin which showed significant molluscicidal activity with LD50 values of 5.39 and 4.3 µg g-1 bw, respectively. Conclusion Isolation of the cardiac glycoside neriifolin from A. obesum and the molluscicidal activity of cerberin and neriifolin against terrestrial snails are reported for the first time. © 2019 Society of Chemical Industry.

Objectives: The objective of this study is to describe the isolation, characterization, and antimicrobial activity of isolated compounds from Tarconanthus camphorantus.Materials and Methods: Bioactive compounds such as trifloculoside, parthenolide (sesquiterpene lactones), lupeol, and erythrodiol (pentacyclic triterpens) were isolated from n-hexane extract of T. camphoratus, and their antimicrobial activity against Candida albicans, Escherichia coli, Psuedomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus, and Mycobacterium smegmatis was evaluated. The compounds were characterized using chromatographic and spectroscopic techniques. Results: Trifloculoside, lupeol, and erythrodiol are being reported for the first time from T. camphoratus. The isolated compounds sesquiterpens and lupeol exhibited prodigious antimicrobial activity against B. subtilis and S. aureus with minimum inhibitory concentration values in the range of 25–1000 µg/mL but no activity was observed against other tested organisms, and erythrodiol showed no antimicrobial activity against any of the tested organisms. Conclusion: The findings of this study revealed that the new compounds trifloculoside, parthenolide, and lupeol isolated from T. camphoratus exhibited effective antimicrobial potential. It was inferred that T. camphoratus can be effectively used in traditional medicine.

A new lupane caffeoyl ester, lup-20(29)-ene 3&beta, caffeate-30-al (7), and a new oleanane-type triterpene, 3&beta, hydroxyolean-13(18)-en-12-one (17), were isolated from the aerial parts of Dobera glabra (Forssk), along with ten known triterpenes, including seven lupane-type lupeol (1), 30-nor-lup-3&beta, ol-20-one (2), ∆1-lupenone (3), lup-20(29)-en-3&beta, 30-diol (4), lupeol caffeate (5), 30-hydroxy lup-20(29)-ene 3&beta, caffeate (6), and betunaldehyde (8), three oleanane-type compounds were also identified, comprising &delta, amyrone (15), &delta, amyrin (16), and 11-oxo-&beta, amyrin (18), together with six sterols, comprising &beta, sitosterol (9), stigmasterol (10), 7&alpha, hydroxy-&beta, sitosterol (11), 7&alpha, hydroxy-stigmasterol (12), 7-keto-&beta, sitosterol (13), and 7-keto-stigmasterol (14). Their structures were elucidated using a variety of spectroscopic techniques, including 1D (1H, 13C, and DEPT-135 13C) and 2D (1H&ndash, 1H COSY, 1H&ndash, 13C HSQC, and 1H&ndash, 13C HMBC) nuclear magnetic resonance (NMR) and accurate mass spectroscopy. Subsequently, the different plant extracts and some of the isolated compounds (1&ndash, 9, 11 and 13) were investigated for their possible cytotoxic activity in comparison to cisplatin against a wide array of aggressive cancer cell lines, such as colorectal cancer (HCT-116), hepatocellular carcinoma (HepG-2), and prostate cancer (PC-3) cell lines. Compound 11 displayed broad cytotoxicity against all of the tested cell lines (IC50 &cong, 8 &micro, g/mL in all cases), and a high safety margin against normal Vero cells (IC50 = 70 &micro, g/mL), suggesting that 11 may be a highly selective and effective anticancer agent candidate. Notably, the evidence indicated that the mode of action of compound 11 could possibly consist of the inhibition of phosphodiesterase I (80.2% enzyme inhibition observed at 2 &micro, M compound concentration).

A new lupane caffeoyl ester, lup-20(29)-ene 3β-caffeate-30-al (7), and a new oleanane-type triterpene, 3β-hydroxyolean-13(18)-en-12-one (17), were isolated from the aerial parts of Dobera glabra (Forssk), along with ten known triterpenes, including seven lupane-type lupeol (1), 30-nor-lup-3β-ol-20-one (2), ∆1-lupenone (3), lup-20(29)-en-3β,30-diol (4), lupeol caffeate (5), 30-hydroxy lup-20(29)-ene 3β-caffeate (6), and betunaldehyde (8); three oleanane-type compounds were also identified, comprising δ-amyrone (15), δ-amyrin (16), and 11-oxo-β-amyrin (18); together with six sterols, comprising β-sitosterol (9), stigmasterol (10), 7α-hydroxy-β-sitosterol (11), 7α-hydroxy-stigmasterol (12), 7-keto-β-sitosterol (13), and 7-keto-stigmasterol (14). Their structures were elucidated using a variety of spectroscopic techniques, including 1D (1H, 13C, and DEPT-135 13C) and 2D (1H–1H COSY, 1H–13C HSQC, and 1H–13C HMBC) nuclear magnetic resonance (NMR) and accurate mass spectroscopy. Subsequently, the different plant extracts and some of the isolated compounds (1–9, 11 and 13) were investigated for their possible cytotoxic activity in comparison to cisplatin against a wide array of aggressive cancer cell lines, such as colorectal cancer (HCT-116), hepatocellular carcinoma (HepG-2), and prostate cancer (PC-3) cell lines. Compound 11 displayed broad cytotoxicity against all of the tested cell lines (IC50 ≅ 8 µg/mL in all cases), and a high safety margin against normal Vero cells (IC50 = 70 µg/mL), suggesting that 11 may be a highly selective and effective anticancer agent candidate. Notably, the evidence indicated that the mode of action of compound 11 could possibly consist of the inhibition of phosphodiesterase I (80.2% enzyme inhibition observed at 2 µM compound concentration).

Extensive research on Ficus species has shown their excellent cytotoxic potential which motivated the authors for further evaluation of its other species. In this article, the β-sitosterol content in the chloroform extract of the leaves of five Ficus species (Ficus carica [FCCE], Ficus nitida [FNCE], Ficus ingens [FICE], Ficus palmata [FPCE], and Ficus vasta [FVCE]) was estimated by a validated high-performance thin-layer chromatography (HPTLC) method along with cytotoxic activity. The chromatography was performed on glass-backed silica gel 60 F254 HPTLC plates with hexane and ethyl acetate (8:2, v/v) as the mobile phase. The developed plate was derivatized with p-anisaldehyde reagent, scanned, and quantified at λ = 550 nm. It furnished a compact and intense peak of β-sitosterol at RF = 0.17 ± 0.001. The contents of β-sitosterol (μg mg−1 of the dried weight of the extract) in the selected Ficus species were found as: FCCE (1.047 μg mg−1) > FVCE (0.771 μg mg−1) > FNCE (0.372 μg mg−1) > FPCE (0.309 μg mg−1)...

A phytochemical investigation of the aerial parts of Nuxia congesta led to the isolation and identification of fifteen compounds, including a new flavonoid, nuxiacin (5-hydroxy-3,8-dimethoxy flavone-7-O-β-D-glycopyranoside) (1). The structure of the new compound was determined using various spectroscopic data including 1D and 2D NMR and mass spectroscopy. All compounds were isolated from N. congesta for the first time. The chemotaxonomic significance of the isolated compounds in the family Stilbaceae and order Lamiales are discussed herein.

A phytochemical study on the stem bark of Commiphora opobalsamum looking for cytotoxic compounds afforded eleven flavonoids, including six previously undescribed prenylated congeners, comophorin A – E, and comophoroside A. The structures of the isolated compounds were elucidated on the basis of spectroscopic evidences and correlated with known compounds. Isolated compounds were biologically evaluated using in vitro cytotoxicity MTT-based assay against two cancer cell lines; namely human hepato-cellular carcinoma (HepG-2) and human breast adenocarcinoma (MCF-7). Comophoroside A revealed to retain the strongest cytotoxic activity against MCF-7 and HepG-2 cell lines with IC 50 values of 8 and 12 μg/mL, respectively.

Three new phenolic glycosides (1–3) together with nine known ones were isolated from the roots of Tecoma mollis using DPPH radical scavenging bioassay-guided chromatographic separation. The structures of the new compounds were established using extensive spectroscopic data and HR-MS. The antioxidant, COX-2 inhibition, and cytotoxic activities were evaluated for the isolated compounds. Compound 4 displayed the strongest radical scavenging activity relative to ascorbic acid with IC50 8.7 μM. Compounds 5, 6, and 10 showed promising COX-2 inhibitory action, IC50 values of 11.3 μM, 9.4 μM, and 13.4 μM, respectively. All compounds exhibited weak cytotoxic activity against Hela and A549 cancer cell lines.

The total extract of Albizia lebbeck flowers was examined in vivo for its possible hepatoprotective activity in comparison with the standard drug silymarin at two doses. The higher dose expressed promising activity especially in reducing the levels of AST, ALT and bilirubin. Fractionation via liquid–liquid partition and reexamination of the fractions revealed that the n-butanol fraction was the best in improving liver biochemical parameters followed by the n-hexane fraction. However, serum lipid parameters were best improved with CHCl3 fraction. The promising biological activity results initiated an intensive chromatographic purification of A. lebbeck flowers fractions. Two compounds were identified from natural source for the first time, the acyclic farnesyl sesquiterpene glycoside1-O-[6-O-α- l -arabinopyranosyl-β- d -glucopyranoside]-(2E,6E-)-farnesol (6) and the squalene derivative 2,3-dihydroxy-2,3-dihydrosqualene (9), in addition to eight compounds reported here for the first time from the genus Albizia; two benzyl glycosides, benzyl 1-O-β- d -glucopyranoside (1) and benzyl 6-O-α- l -arabinopyranosyl β- d -glucopyranoside (2); three acyclic monoterpene glycosides, linalyl β- d -glucopyranoside (3) and linalyl 6-O-α- l -arabinopyranosyl-β- d -glucopyranoside (4); (2E)-3,7-dimethylocta-2,6-dienoate-6-O-α- l arabinopyranosyl-β- d -glucopyranoside (5), two oligoglycosides, n-hexyl-α- l arabinopyranosyl-(1 → 6)-β- d -glucopyranoside (creoside) (7) and n-octyl α- l -arabinopyranosyl-(1 → 6)-β- d -glucopyranoside (rhodiooctanoside) (8); and ethyl fructofuranoside (10). The structures of the isolated compounds were elucidated based on extensive examination of their spectroscopic 1D and 2D-NMR, MS, UV, and IR data. It is worth mentioning that, some of the isolated linalol glycoside derivatives were reported as aroma precursors.

Background: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an emerging novel coronavirus responsible for the viral pneumonia outbreak (coronavirus disease-19 [COVID-19]) that has impacted millions of people, causing a tremendous global public health concern and number of fatalities. The development of novel antiviral agents is considered an urgent research subject. Objectives: The objective of the study is to discover the phenolic constituents of the methanolic extract of Tecoma mollis Humb. and Bonpl. heartwood and to investigate their potential inhibitory action against SARS-CoV-2 protease and/or entry proteins. Materials and Methods: The heartwood of T. mollis was extracted by maceration with 70% EtOH until complete exhaustion. The extract was concentrated under reduced pressure, mixed with distilled H2O and defatted with CHCl3 to produce a CHCl3 fraction, and then subjected to solvent fractionation with n-butanol to produce an n-butanol fraction. The n-butanol fraction was subjected to a silica gel column using CHCl3–MeOH gradient mixtures followed by reversed-phase high-performance liquid chromatography. The isolated compounds were identified using one- and two-dimensional nuclear magnetic resonance as well as mass spectroscopy. Molecular docking studies have been implemented to identify the binding pattern between ligands and target enzymes, i.e. main protease (Mpro) and spike protein receptor-binding domain (RBD), and compared with the currently used COVID-19 inhibitors. Molecular dynamic simulations have been performed to evaluate the dynamics and stability of protein–ligand complexes. The obtained information is then correlated with the essential structural features, and finally the structure–activity relationship is suggested. Results: Fourteen phenolic glycosides were isolated from the methanolic extract of T. mollis Humb. and Bonpl. heartwood in addition to an iridoid, ixoside. The molecular docking study exhibited that the isolated compounds have a higher binding affinity toward the active site of Mpro and the angiotensin-converting enzyme-2 binding site of spike protein RBD. The phenylpropanoids have higher inhibitory action with higher binding energy toward SARS-CoV-2 Mpro protease as compared to spike protein RBD. Among all the isolated compounds, isoverbascoside (10) exhibited the most potent dual interaction with SARS-CoV-2 Mpro protease and spike protein RBD with high binding energy of − 8.8 and − 7.2 kcal/mol, respectively. This showed better potency than the currently used Mpro and spike–protein inhibitors. Conclusion: Our study is the first report on the potential inhibitory action of phenylpropanoids for SARS-CoV-2 protease and spike protein. It also correlates between the reported antiviral activities of some isolated compounds with their potential inhibitory action for COVID-19 viral proteins. Our results on T. mollis extract constituents could help in the discovery of a promising repurposable drug candidate that could contribute to the development of an effective therapy for COVID-19.

Cichorium intybus L., (chicory) is employed in various traditional medicines to treat a wide range of diseases and disorders. In the current investigation, two new naphthalane derivatives viz., cichorins D (1) and E (2), along with one new anthraquinone cichorin F (3), were isolated from Cichorium intybus. In addition, three previously reported compounds viz., &beta, sitosterol (4), &beta, sitosterol &beta, glucopyranoside (5), and stigmasterol (6) were also isolated from Cichorium intybus. Their structures were established via extensive spectroscopic data, including 1D (1H and 13C) and 2D NMR (COSY, HSQC and HMBC), and ESIMS. Cichorin E (2) has a weak cytotoxic effect on breast cancer cells (MDA-MB-468: IC50: 85.9 &micro, M) and Ewing&rsquo, s sarcoma cells (SK-N-MC: IC50: 71.1 &micro, M), cichorin F (3) also illustrated weak cytotoxic effects on breast cancer cells (MDA-MB-468: IC50: 41.0 &micro, M and MDA-MB-231: IC50: 45.6 &micro, M), and SK-N-MC cells (IC50: 71.9 &micro, M). Moreover compounds 1&ndash, 3 did not show any promising anthelmintic effects.

Objective: To optimize the ultrasonication method for efficient extraction of P-sitosterol and lupeol from the roots of Astragalus atropilosus using Box-Behnken design of response surface methodology (RSM), and its validation by high performance thin layer chromatography (HPTLC) method. Methods: Ultrasonication method was used to extract β-sitosterol and lupeol from Astragalus atropilosus (roots). RSM was used to optimize the different extraction parameters viz. liquid to solid ratio (10-14 mL/g), temperature (60-80 °C) and time (40-60 min) to maximize the yield of β-sitosterol and lupeol. The quantitative estimation of β-sitosterol and lupeol was done in chloroform extract of Astragalus atropilosus by validated HPTLC method on 10 cm × 20 cm glass-backed silica gel 60F254 plate using hexane and ethyl acetate (8:2, v/v) as mobile phase. Results: A quadratic polynomial model was found to be most appropriate with regard to R1 (yield of total extraction; R2/% CV = 0.994 8/0.28), R2 (β-sitosterol yield; R2/% CV = 0.992 3/0.39) and R3 (lupeol yield; R2/% CV = 0.994 2/0.97). The values of adjusted R2/predicted R2/signal to noise ratio for R1, R2, and R 3 were 0.978 2/0.955 1/48.77, 0.990 4/0.911 0/31.33, and 0.992 7/0.940 1/36.08, respectively, indicating a high degree of correlation and adequate signal. The linear correlation plot between the predicted and experimental values for R1, R2, and R3 showed high values of R2 ranging from 0.990 5-0.997 3. β-sitosterol and lupeol in chloroform extract of Astragalus atropilosus were detected at Rf values of 0.22 and 0.34, respectively, at X max = 518 nm. The optimized ultrasonic extraction produced 8.462% w/w of Rl, 0.451% w/w of R2 and 0.172% w/w of R3 at 13.5 mL/g liquid to solid ratio, 78 C of temperature and 60 min of time. Conclusions: The experimental findings of RSM optimized extraction and HPTLC analysis can be further applied for the efficient extraction of β-sitosterol and lupeol in other species of Astragalus.

Salvadora persica L. is a popular chewing stick commonly known as “miswak”. During our ongoing research activities on the chemical constituents of Salvadora persica roots, which is a new sulphur-containing imidazoline alkaloid 1,3-Dibenzyl-4-(1,2,3,4-tetrahydroxy-butyl)-1,3-dihydro-imidazole-2-thione, persicaline, (1) along with five known compounds (2–6) are identified. Compounds (2, 3) were reported for the first time from the family Salvadoraeceae. The structure of the new compound was established by extensive spectroscopic data and HR-MS. The antioxidant activities of the fractions and isolates were evaluated using different in vitro methods, such as DPPH, superoxide anion and nitric oxide radicals scavenging assays. Compound (1) showed a promising antioxidant activity with IC50 0.1, 0.08, and 0.09 µM in the three assays, respectively, comparable to ascorbic acid.

Summary A simple and sensitive high-performance thin-layer chromatographic (HPTLC) method was developed for the evaluation of biomarker β-amyrin in the leaves of five different species of genus Ficus (Ficus carica, Ficus nitida, Ficus ingens, Ficus palmata, and Ficus vasta) grown in the Kingdom of Saudi Arabia. Chromatography was performed on glass-backed silica gel 60 F 254 HPTLC plates with solvents toluene–methanol (9:1, v/v) as the mobile phase. After development, the HPTLC plate was derivatized with p-anisaldehyde reagent to give well-resolved and compact spot of β-amyrin. Scanning and quantification were done at 550 nm. The system was found to give compact spot for β-amyrin at R F = 0.58. The linear regression analysis data for the calibration plots showed good linear relationship with r 2 = 0.998 with respect to area in the concentration range of 100–900 ng. The regression equation for β-amyrin standard was found to be Y = 5.835X + 87. The precisions (n = 6) for β-amyrin were found to be 1.64–1.77% and 1.68–1.84%, respectively, for intra-day and inter-day batches, and the recovery values were found to be 97.6–98.3%. β-Amyrin was found to be present in three species, i.e., F. carica (0.29%, w/w), F. nitida (0.54% w/w), and F. palmata (0.31%, w/w), while it was absent in F. vasta and F. ingens. The statistical analysis proves that the developed method for the quantification of β-amyrin is reproducible; hence, it can be em ployed for the determination of β-amyrin in plasma and other biological fluids as well as in finished products available in the market.

Summary A simple and sensitive high-performance thin-layer chromatographic (HPTLC) method was developed for the evaluation of biomarker lupeol in the leaves of five different species of genus Ficus (Ficus carica, Ficus nitida, Ficus ingens, Ficus palmata, and Ficus vest) belonging to family Moraceae. Chromatography was performed on glass-backed silica gel 60 F 254 precoated HPTLC plates with solvents toluene–methanol (9:1, v/v) as the mobile phase. After development, the HPTLC plate was derivatized with p-anisaldehyde reagent, scanned, and quantified at 540 nm. The system was found to give compact spot for lupeol at RF = 0.32 ± 0.01. The precisions and accuracy (n = 6) for lupeol were found to be 1.47–1.64% and 1.63–1.86%, and 99–100% and 99.4–99.7%, respectively, for inter-day and intra-day. Lupeol was found to be present in four species, i.e., F. carica (0.4%, w/w), F. nitida (1.4%, w/w), F. palmata (0.33%, w/w), and F. vest (0.59%, w/w), while it was absent in F. ingens. The statistical analysis proved that the developed method is reproducible and selective. The developed method can be used as an important tool to assure the therapeutic dose of active ingredients in herbal formulations as well as for standardization and quality control of bulk drugs and in-process formulations. This method can also be employed for the further study of degradation kinetics and determination of lupeol in plasma and other biological fluids.

A new acylatediridoid glycoside, 6-O-α-L-(2″-acetyl-4″-O-trans-isoferuloyl) rhamnopyranosyl catalpol (9) together with 18 known compounds belonging to the iridoids, flavonoids, triterpene saponin glycosides and phenylethanoids (1-8, 10-18) were isolated from the aerial parts and the flowers of Buddleja polystachya. Their structures were elucidated on the basis of spectroscopic evidence and comparison with that reported in the literature. Promising adulticidal activity was shown for all extracts when tested for adulticidal and larvicidal activities against Ae. aegypti mosquitoes. Therefore, isolated compounds (1-10, 12-14 and 19) were bioassayed for their adulticidal activity. Compound 1 (phytol) was highly active with an LD50 value of 1.27 ± 0.08 μg/mosquito against adult female Ae. aegypti.

A radical scavenging guided phytochemical study on the leaf of Simmondsia chinensis afforded ten flavonoids (1–10) and four lignans (11–14). The structures of the isolated compounds were elucidated on the basis of spectroscopic evidences and correlated with known compounds. Among isolated compounds, flavonoid aglycones (1–4) showed stronger antioxidant activity than their glycosides (5–10) whilst lignan glycosides (11–14) showed moderate to weak antioxidant activity using DPPH and β-carotene methods in relation to BHT (positive control). The inhibitory potential against enzyme lipoxygenase was also evaluated for isolated compounds exhibiting variable potency. For flavonoids, glycosides are less potent inhibitors than free aglycones. Quercetin is the most potent inhibitor with an IC50 of 5.6 μM. Lignoid glycosides exhibited moderate to weak inhibitory effect against lipoxygenase enzyme. Luteolin was used as a positive control in lipoxygenase inhibiting assay.

A novel 6-hydroxy-8,11,11-trimethyl-bicyclo[7.2.0]undec-4-ene-4-carboxylic acid 1 has been isolated from leaves of Iphiona scabra DC. Its structure has been established on the basis of chemical and physical evidence (IR, ¹H NMR, ¹³C NMR, and MS) and further confirmed by single-crystal X-ray diffraction study. The in vitro antioxidant activities of isolated compound 1 and extracts were evaluated by 1,1-diphenyl-2-picrylhydrazyl method.

Six new triterpenoid saponins, including four bisdesmosidic compounds, contortisiliosides H – K (1 – 4), and two monodesmosidic compounds, contortisiliosides L and M (7, 8), along with two known ones, contortisiliosides E and F (5, 6) were isolated from the ethanolic extract of the pericarps of Enterolobium contortisiliquum (Leguminosae). Their structures were determined using different spectroscopic techniques and acid hydrolysis. The cytotoxic and antimicrobial activities were then evaluated for the isolated compounds. Among isolated saponins, the most potent cytotoxic activity was observed with contortisilioside E (5) toward human hepatocellular carcinoma (IC50 18.9 μM) and human promyelocytic leukemia (IC50 15.6 μM) cell lines. The antimicrobial evaluation performed using serial dilution method to determine the minimum inhibitory concentration (MIC) revealed that contortisilioside L (7) has a moderate antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans (MICs = 25 μM).

Five xanthone derivatives and one flavanol were isolated from the dichloromethane extract of Garcinia mangostana. Dichloromethane, ethyl acetate extract and the major xanthone (α-mangostin) were evaluated in vitro against erythrocytic schizonts of Plasmodium falciparum, intracellular amastigotes of Leishmania infantum and Trypanosoma cruzi and free trypomastigotes of T. brucei. The major constituent α-mangostin was also checked for antimicrobial potential against Candida albicans, Escherichia coli, Pseudomonas aeruginosa, Bacillius subtilis, Staphylococcus aureus, Mycobacterium smegmatis, M. cheleneoi, M. xenopi and M. intracellulare. Activity against P. falciparum (IC50 2.7 μg/mL) and T. brucei (IC50 0.5 μg/mL) were observed for the dichloromethane extract, however, with only moderate selectivity was seen based on a parallel cytotoxicity evaluation on MRC-5 cells (IC50 9.4 μg/mL). The ethyl acetate extract was inactive (IC50 > 30 µg/mL). The major constituent α-mangostin showed rather high cytotoxicity (IC50 7.5 µM) and a broad but non-selective antiprotozoal and antimicrobial activity profile. This in vitro study endorses that the antiprotozoal and antimicrobial potential of prenylated xanthones is non-conclusive in view of the low level of selectivity.

The present study assessed the comparative antioxidant potential of the ethanol extract (EE) of leaves of four Acacia species (Acacia salicina, AS; Acacia laeta, AL; Acacia hamulosa AH; and Acacia tortilis, AT) grown in Saudi Arabia, including RP-HPTLC quantification of antioxidant biomarker rutin. In vitro DPPH radical scavenging and β-carotene-linoleic acid bleaching assays showed the promising antioxidant activities of Acacia extracts: ASEE (IC50: 60.39 and 324.65 μg/ml) >ALEE (IC50: 217.06 and 423.36 μg/ml) >ATEE (IC50: 250.13 and 747.50 μg/ml) >AHEE (IC50: 255.83 and 417.28 μg/ml). This was comparable to rutin tested at 500 μg/ml. Further, a RP- HPTLC densitometric method was developed (acetonitrile:water; 6:4; v/v) using glass-backed RP-18 silica gel F254 plate, and scanned at UV max 254 nm. The method was validated as per the ICH guidelines. Analysis of the validated RP-HPTLC displayed an intense peak (Rf = 0.65 ± 0.004) of rutin that was estimated (μg/mg dry weight) to be highest in ASEE (10.42), followed by ALEE (2.67), AHEE (1.36) and ATEE (0.31). Taken together, presence of rutin strongly supported the high antioxidant property of the tested Acacia species, especially Acacia salicina. The developed RP-HPTLC method therefore, affirms its application in the quality control of commercialized herbal drugs or formulation containing rutin.

Phytochemical investigations of the ethanolic extract of leaves of Clutia lanceolata (Family: Euphorbiaceae) resulted in the isolation of four compounds viz. 3,4-dihydroxy-2-methylbenzoic acid (1), 2,2′-dihydroxy-1,1′-binaphthyl (2), 1,3,8-trihydroxy-6-methylanthracene-9,10-dione (3) and 5-hydroxy-1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-1,4,6-trien-3-one (4). Although all the isolated compounds were known but this was the first report from this plant source. Their structures were established on the basis of chemical and physical evidences viz. elemental analysis, FT-IR, 1H-NMR, 13C-NMR and mass spectral analysis. Structure of compound 2 and 4 was further authenticated by single-crystal X-ray analysis and density functional theory calculations. The isolated compounds (1–4) were screened for AChE enzyme inhibition assay in which compound 3 and 4 were found to be more potent AChE inhibitor. Molecular docking study of potent AChE inhibitor was performed to find the probable binding mode of the compounds into the active site of receptor. Moreover, the isolated compounds were also screened for in vivo cytotoxicity by brine shrimp lethality assay. Graphical Abstract Electronic supplementary material The online version of this article (doi:10.1007/s13659-016-0110-x) contains supplementary material, which is available to authorized users.

The present study assessed the comparative antioxidant potential of the ethanol extract (EE) of leaves of four Acacia species (Acacia salicina, AS; Acacia laeta, AL; Acacia hamulosa AH; and Acacia tortilis, AT) grown in Saudi Arabia, including RP-HPTLC quantification of antioxidant biomarker rutin. In vitro DPPH radical scavenging and β-carotene-linoleic acid bleaching assays showed the promising antioxidant activities of Acacia extracts: ASEE (IC50: 60.39 and 324.65 μg/ml) >ALEE (IC50: 217.06 and 423.36 μg/ml) >ATEE (IC50: 250.13 and 747.50 μg/ml) >AHEE (IC50: 255.83 and 417.28 μg/ml). This was comparable to rutin tested at 500 μg/ml. Further, a RP- HPTLC densitometric method was developed (acetonitrile:water; 6:4; v/v) using glass-backed RP-18 silica gel F254 plate, and scanned at UV max 254 nm. The method was validated as per the ICH guidelines. Analysis of the validated RP-HPTLC displayed an intense peak (Rf = 0.65 ± 0.004) of rutin that was estimated (μg/mg dry weight) to be highest in ASEE (10.42), followed by ALEE (2.67), AHEE (1.36) and ATEE (0.31). Taken together, presence of rutin strongly supported the high antioxidant property of the tested Acacia species, especially Acacia salicina. The developed RP-HPTLC method therefore, affirms its application in the quality control of commercialized herbal drugs or formulation containing rutin.

Phytochemical study of the CH(2)Cl(2) soluble fraction of the aerial parts of R. natalensis resulted in the isolation and identification of six flavonoid derivatives, β-amyrin and β-sitosterol glucoside (daucosterol). The isolated compounds were identified utilizing physical, chemical and different spectral methods including UV, 1D- 2D-NMR and MS. The compounds were identified as four flavanones; 7-O-methyl hesperetin (1), 7-O-methyl naringenin (4), (-)-homoeriodictyol (eriodictyonone) (5), eriodictyol-7-methyl ether (6) and two flavones; 7-O-methyl isokaemferide (2) and genkwanin (3). The isolated compounds as well as some available standards representing structurally similar flavones and flavanones were used to study their antioxidant potential using DPPH and try to explore the impact of structures on the antioxidant activity. In other assays flavanones were less active than flavones as antioxidant due to lack of the C-4 carbonyl group in conjugation with 2,3-double bond. However, in DPPH assay based on the ability of molecules to donate hydrogen flavanones were found more active than flavones.

From leaves of Rhus alata, one new benzofuranic acid named [(2E)-3-(4-hydroxy-5,7-dimethyl- benzo[3,4-b] furan-6-yloxy)-prop-2-enoic acid has been isolated together with eight known compounds: dimethyl ester of terephthalic acid, beta-amyrin, friedelin, lupeol, beta-sitosterol, oleanolic acid, taraxerone and ethyl gallate. Structural elucidations were done on the basis of chemical and physical data (IR, UV, 1H-NMR, 13C-NMR and MS spectra).

Further investigation of different fractions from Lotus polyphyllos Clarke roots resulted in the isolation of the new 3-arylcoumarin derivative; 4',6'-dihydroxy-7, 2'-dimethoxy-3-arylcoumarin (5). In addition, the known compounds beta-sitosterol, 1-hexacosanol (1), n-tetracosyl p-coumarate (2), 4'-O-methylderrone (4), and quercetin (6) were identified. The structures were determined from spectroscopic data including 1D- and 2D-NMR experiments.

Biomarker β-amyrin was analyzed in the leaves of four different Acacia species (A. salicina, A. loreta, A. hamulosa and A. tortilis) grown in Kingdom of Saudi Arabia by a validated HPTLC method. The chromatography was performed on glass-backed silica gel 60 F254 HPTLC plates using solvents toluene: methanol (9:1, v/v) as mobile phase. The developed TLC plate was derivatized with anisaldehyde and scanned at 520 nm. A sharp peak of β-amyrin was found at Rf=0.58±0.01. The r2 and the linear regression equation for β-amyrin was found to be 0.991 and 19.913X+107.803, respectively in the concentration range of 100-800 ng. The percentage of β-amyrin was found to be maximum 2.70% w/w in A. tortilis, 1.85% w/w in A. loreta and 1.80% w/w in A. hamulosa while it was totally absent in A. salicina. This study conceives maiden reporting of quantification of β-amyrin in four different species of Acacia by validated HPTLC method. The developed method for the analysis of β-amyrin was proved to be reproducible by statistical analysis hence it can be employed for further analysis of β-amyrin in plasma, other biological fluids and in finished products available in the market.

A radical-scavenging, guided phytochemical study of the latex of Calotropis Procera afforded five lignans (1–5), including a new one (4). The structural determination was accomplished using 1D- and 2D-NMR, high-resolution electrospray ionization mass spectrometry (HRESIMS), and correlation with known compounds. Among the isolated compounds, acylated lignans (3–5) showed stronger antioxidant activity than non-acylated derivatives (1,2). Anti-inflammatory activity was evaluated by determining the inhibitory potential against 5- and 15-lipoxygenase enzymes. The highest anti-inflammatory activity was observed in compound 4, with IC50s values of 7.6 µM and 2.7 µM against 5-LOX and 15-LOX, respectively.

In the present study an analytical method of high-performance thin-layer chromatography (HPTLC) has been developed for quantification of glycyrrhizin for marketed antistressliquorice root capsules (LRC) and herbal tea (HT). Chromatography was performed by using mobile phase ethyl acetate (EA): glacial acetic acid (GAA): Methanol (MeOH): water (H(2)O) in proportion of 6:2:2:1, v/v/v/v. The developed plate was scanned and quantified densitometrically at absorption maxima 254nm. The method was validated for various analytical parameters viz. precision, accuracy, recovery, robustness, specificity, detection and quantification limits. The developed system was found to give compact spot for glycyrrhizin (R(f)= 0.33± 0.001). The linearity relationship was described by the equation Y=6.841X+ 70.428. The limit of detection (34 ng band(-1)), limit of quantification (101 ng band(-1)), recovery (99.4-99.8%), and precision (1.84% and1.62%; intraday and interday, respectively) were found satisfactory for glycyrrhizin. Linearity range for glycyrrhizin was 100-600ng (r(2)=0.998). The amount of glycyrrhizin was estimated by comparing the peak area of standard and the same was present in crude extract. The content of glycyrrhizin was estimated as 11.4% and 4.7% w/w in sample LRC and HT, respectively. The proposed method will be useful to quantify the therapeutic dose of glycyrrhizin in herbal formulations as well as in bulk drug.

A new chromone, named 5,6-dihydroxy-2-methylchromone (FL-2), along with seven known flavonoids, 5-hydroxy-7,3,3′,4′-tetramethoxyflavone (FL-3), 5,4′-dihydroxy-6,7,8-trimethoxyflavone (FL-4), 5,4′-dihydroxy-7,8-dimethoxyflavone (FL-5), 4-methoxychalcone (FL-6), 7,4′-dimethoxyapigenin (FL-7), 5,7,4′-trihydroxy-2′,3′,6′-trimethoxyisoflavone (FL-8 a rare flavonoid), acacetin-7-O-glucoside (FL-9) and acacetin-7-O-neohesperidoside (FL-10), and β-sitosterol-d-glucoside (FL-1) have been isolated from the leaves of Ficus lyrata. Their structures have been established on the basis of chemical and spectral evidence (IR, UV, 1H NMR, 13C NMR and mass spectra).

Chromatographic purification of the n-hexane and dichloromethane extracts of Nuxia oppositifolia aerial parts, growing in Saudi Arabia, resulted in the isolation and characterization of three new labdane-type diterpene acids, 2β-acetoxy-labda-7-en-15-oic acid (1), 2β-acetoxy-7-oxolabda-8-en-15-oic acid (2), 2β-acetoxy-6-oxolabda-7-en-15-oic acid (3), and one new seco-triterpene, 3,4-seco olean-12-en-3,30 dioic acid (4), together with 10 known lupane, oleanane and ursane-type triterpenes, as well as the common phytosterols, β-sitosterol and stigmasterol (5–16). Their structures have been assigned on the basis of different spectroscopic techniques including 1D and 2D NMR. Moreover, 13 of the isolated compounds were tested on the human cancer cell lines HeLa (cervical), A549 (lung) and MDA (breast), and most of the compounds showed potent cytotoxic activities in vitro.

A novel isoflavone, 5,7-dihydroxy-4'- p-methyl benzyl isoflavone 1a, and three known flavonoids apigenin, luteolin and quercetin have been isolated from the leaves of Acacia tortilis. Their structures were elucidated by chemical and physical data (IR, UV, 1 H-NMR, 1 3 C-NMR and MS spectra).