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A new benzofuran derivative, nervione (1), was isolated from Nervilia concolor (Blume) Schltr. (Orchidaceae). Eight previously reported compounds were also isolated: 5,7-dimethoxyflavone (2), 3,5,7-trimethoxyflavone (3), 7-methoxyflavone (4), 3,7-dimethoxy-5-hydroxyflavone (5), tetramethylscutellarein (4',5,6,7-tetramethoxyflavone) (6), 5,7-dimethoxy-4'-hydroxyflavone (7), rhamnetin (8), and 5,7-dihydroxy-3’,4’-dimethoxyflavone (9). The structures were elucidated by 1D, 2D NMR, and HRESIMS spectroscopy in addition to the literature. The relative configuration of 1 was defined using DP4+ probability while its absolute configuration was defined by comparison of the ECD spectrum of 1 with those of previously reported compounds. All isolated compounds were evaluated for alpha-glucosidase inhibition, revealing weak or no activity.

Chemical investigation on chloroform extract of Phlogacanthus turgidus led to the isolation of one new compound namely turgidol, together with five known triterpenoids, lupeol, lupenone, betulin, betulinic acid, and taraxerol. Their structures and stereochemistry have been determined by 1 D and 2 D NMR analysis, high resolution mass spectrometry, and compared with those in literatures. The relative configuration of turgidol was defined using DFT-NMR chemical shift calculations and subsequent DP4+ probability method. Turgidol, betulin, and betulinic acid were evaluated for cytotoxic activity toward K562 cancer cell line and the alpha-glucosidase inhibition.

Two new phenolic compounds, cristiferides A-B (1-2) together with six known compounds, 2,4-dihydroxyphthalide (3), lecanoric acid (4), orsellinic acid (5), 5-chloroorsellinic acid (6), methyl haema...

Chemical investigation of the Vietnamese plant Aegiceras floridum Roem. & Schult. (Primulaceae) led to the isolation of the new compound 3-methoxy-5-nonylphenol (1) along with five known ones 2,8,10-trihydroxy-6H-benzo[c]chromen-6-one (2), 2-hydroxy-5-methoxy-3-nonylbenzo-1,4-quinone (3), 5-(3-hydroxypropyl)-7-methoxy-3-(methylbenzofuran-2-yl)-3-methoxyphenol (4), 2,8-dihydroxy-7-methoxy-3,9-diundecyldibenzofuran-1,4-dione (5) and 10-hydroxy-4-methoxy-2,11-diundecylgomphilactone (6). The structures were elucidated by analysis of their HRESIMS and NMR data as well as the comparison of their NMR data with those reported in the literature. The cytotoxic activity of selected isolated compounds against some cancer cell lines such as human epithelial carcinoma (HeLa), human lung cancer (NCI-H460), liver hepatocellular carcinoma (HepG2), human breast cancer (MCF-7), and acute T cell leukemia (Jurkat) was evaluated. Among them, 3 showed moderate activities against MCF-7 with an IC50 of 17.77 µM and NCI-H460 with an IC50 of 25.02 µM. The result of DPPH radical scavenging activity assay indicated that compounds 2–4 and 6 revealed weak antioxidant activity.

A novel dimeric alkylresorcinol derivative, manilkzapotane (1), along with seven known compounds, lupeol acetate (2), lupeol (3), arjunolic acid (4), ergosterol peroxide (5), taraxerol (6), hederagonic acid (7), and glochidiol (8) were isolated from the stem bark of Manilkara zapota. Their structures were determined on the basis of spectroscopic data. DFT-NMR chemical shift calculations and a modified probability (DP4+) method were applied to define the relative configuration of 1. To the best of our knowledge, this represents the first isolation of a dimeric alkylresorcinol derivative from the Sapotaceae family.

Chemical investigation of the lichen Usnea ceratina Arch led to the isolation of five depsidones, including one new compound ceratinalone (1) along with four known compounds bailesidone (2), stictic acid (3), 8'-O-methylstictic acid (4) and 8'-O-ethylstictic acid (5). The structures were determined by analysis of their MS and NMR data as well as by comparison with literature values. Compounds 1 and 4 were evaluated the cytotoxic activity against HeLa (human epithelial carcinoma), NCI-H460 (human lung cancer), HepG2 (liver hepatocellular carcinoma), and MCF-7 (human breast cancer) cell lines, showing the moderate activity.

Three new depsidones, parmosidones F – G (1 – 2), and 8′-O-methylsalazinic acid (3), and 3 new diphenylethers, parmetherines A – C (4 – 6), together with 2 known congeners were isolated from the whole thalli of Parmotrema dilatatum, a foliose chlorolichen. Their structures were unambiguously determined by extensive spectroscopic analyses and comparison with literature data. The isolated polyphenolics were assayed for their α-glucosidase inhibitory activities. Newly reported benzylated depsidones 1 and 2 in particular inhibited α-glucosidase with IC50 values of 2.2 and 4.3 µM, respectively, and are thus more potent than the positive control, acarbose.

Phytochemical analysis of Euphorbia antiquorum stem extracts afforded two new ent-atisane compounds, ent-3α-acetoxy-16β,17,18-trihydroxyatisane (1) and ent-3α,14,16β,17-tetrahydroxyatisane (2) toge...

Lichens, a natural source producing a number of valuable compounds is economically not feasible and profitable due to its slow growth. Mycobiont cultures are alternative sources which have become highly attractive for chemists recently. Mycobiont of Graphis sp., a native lichens in Vietnam was separated then cultivated in test tubes. The present study aimed to identify chemical constituents of the cultured mycobiont of Graphis sp. Multiple chromatographic methods were applied to isolate three eremophilane sesquiterpenes including one new compound, graphilane (1) and two known compounds sporogen-AO-1 (2) and dihydrosporogen-AO-1 (3). Their chemical structures was elucidated by extensive 1 D and 2 D NMR analysis and high resolution mass spectroscopy as well as comparisons in literature. Compound 1 was evaluated for the cytotoxic activity against K562 cancer cell line and revealed moderate activity with IC50 value of 87.20 ± 0.76 µM.

A new norlupane triterpenoid, 29-norlupane-1β-hydroxy-3,20-dione (1), along with ten known compounds, 29-norlup-1-ene-3,20-dione (2), phyllanthol (3), phyllanthone (4), glochidone (5), lupeol (6), lupeone (7), 4-hydroxybenzoic acid (8), 4-hydroxybenzaldehyde (9), phyllane A (10) and methyl β-orsellinate (11) were isolated the twigs and leaves of Phyllanthus acidus. The structure of 1 was identified by interpretation of their spectroscopic data and comparison with those reported in the literature. In addition, all isolated compounds 1-11 were evaluated for their antioxidant activity.

Two new cycloartanes, combretanones G and H (1 and 2), were isolated from the leaves of Combretum quadrangulare. Their structures were elucidated by applying a set of spectroscopic methods, while their relative configurations were determined using DFT-NMR chemical shift calculations and subsequent assignment of DP4 probabilities. Compounds 1 and 2 are C-23/C-24 stereoisomers of the previously-reported euphonerin E. Both exhibited moderate cytotoxicity against three human cancer cell lines. Compound 2 was shown to be a potent antiparasitic. Our results confirm the traditional medicinal uses of Combretum quadrangulare in Vietnam.

A new labdane-type diterpenoid, named vitexnegundin (1), along with seven known compounds, including vitexilactone (2), vitetrifolin D (3), 13-hydroxy-5(10),14-halimadien-6-one (4), (rel 3S,5S,8R,9R,10S)-3,9-dihydroxy-13(14)-labden-16,15-olide (5), artemetin (6), vitexcarpin (7) and penduletin (8), were isolated from the leaves of Vitex negundo L. Their structures were elucidated by using spectroscopic methods, X-ray crystallographic analysis and comparison with those reported in the literature. Moreover, all isolated compounds 1–8 were evaluated for their antimicrobial activity against ESBL-producing Escherichia coli strain and methicillin-resistant Staphylococcus aureus.

A novel 3,4-dihydroisocoumarin, lindermyrrhin (1), along with three known compounds, quercetin (2), northalifoline (3) and N-formyl-laurolitsine (4) were isolated from the roots of Lindera myrrha. The structure of compound 1 was identified by interpretation of their spectroscopic data as well as comparison with those reported in the literature. The novel compound 1 represents the first 3,4-dihydroisocoumarin bearing a 2-hydroxyisopropyl substituent at C-3.

A series of usnic acid benzylidene derivatives (groups I-V) were designed, synthesized and evaluated for their anticancer activity in the search for potentially new anticancer agents. Compounds 1a, 5b, 2b, 2e and 2f exhibited the most potent cytotoxcity against K562 cell line with IC50 values of 10.0 ± 3.6, 5.6 ± 0.4, 8.8 ± 1.0, 4.5 ± 0.1 and 8.4 ± 0.4 μM, respectively. It is noteworthy that compound 2e displayed potent cytotoxicity against K562 cells without any cytotoxic effect on HEK293 normal cell line.

Combretum quadrangulare Kurz is widely used in folk medicine in Eastern Asia and is associated with various ethnopharmacological properties including hepatoprotective, antipyretic, analgesic, antidysenteric, and anthelmintic activities. Previous phytochemical investigations reported the presence of numerous triterpenes (mostly cycloartanes, ursanes, lupanes, and oleananes) along with dozens of flavonoids. However, the extracts of C. quadrangulare and isolated flavonoids have not been evaluated for their alpha-glucosidase inhibition. In the frame of our efforts dedicated to the chemical investigation of Vietnamese medicinal plants and their biological activities, a phytochemical study of the MeOH extract of the leaves of C. quadrangulare using bioactive guided isolation was undertaken. In this paper, the isolation and structure elucidation of twelve known compounds, 5-hydroxy-3,7,4′-trimethoxyflavone (1), ayanin (2), kumatakenin (3), rhamnocitrin (4), ombuin (5), myricetin-3,7,3′,5′-tetramethyl ether (6), gardenin D (7), luteolin (12), apigenin (13), mearnsetin (14), isoorientin (15), and vitexin (16) were reported. Bromination was applied to compounds 2 and 3 to provide four new synthetic analogues 8–11. All isolated and synthesized compounds were evaluated for alpha-glucosidase inhibition and antibacterial activity. Compounds 4 and 5 showed moderate antibacterial activity against methicillin-resistant Staphylococcus aureus while others were inactive. All compounds failed to reveal any activity toward extended spectrum beta-lactamase-producing Escherichia coli. Compounds 2, 4, 6–9, and 11–14 showed good alpha-glucosidase inhibition with IC50 values in the range of 30.5–282.0 µM. The kinetic of enzyme inhibition showed that 8 and 11 were noncompetitive type inhibition against alpha-glucosidase. In silico molecular docking model indicated that compounds 8 and 11 were potential inhibitors against enzyme α-glucosidase.

Bioactive-guided phytochemical investigation of Euphorbia antiquorum L. growing in Vietnam led to the isolation of five ent-atisanes, one seco-ent-atisane, and one lathyrane (ingol-type). The structures were elucidated as ent-1α,3α,16β,17-tetrahydroxyatisane (1), ethyl ent-3,4-seco-4,16β,17-trihydroxyatisane-3-carboxylate (2), ent-atisane-3-oxo-16β,17-acetonide (3), ent-3α-acetoxy-16β,17-dihydroxyatisane (4), ent-16β,17-dihydroxyatisane-3-one (5), calliterpenone (6), and ingol 12-acetate (7). Their chemical structures were unambiguously determined by analysis of one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) and high resolution mass spectrometry, as well as by comparison with literature data. Among them, 1 is a new compound while 2 is an ethylated artifact of ent-3,4-seco-4,16β,17-trihydroxyatisane-3-carboxylic acid, a new compound. Isolates were evaluated for alpha-glucosidase inhibition. Compound 3 showed the most significant inhibitory activity against alpha-glucosidase with an IC50 value of 69.62 µM. Further study on mechanism underlying yeast alpha-glucosidase inhibition indicated that 3 could retard the enzyme function by noncompetitive.

Chemical investigation of the lichen Parmotrema indicum Hale led to the isolation of one new diphenyl ether, parmetherine D (1), along with eight known compounds (2-9). The structures were determined by analysis of MS and NMR data and by comparison with the literature. Compounds 1, 2, and 7 were evaluated for α-glucosidase inhibition. Only compound 1 exhibited significant inhibition.

This study investigated a set of new potential antidiabetes agents. Derivatives of usnic acid were designed and synthesized. These analogs and nineteen benzylidene analogs from a previous study were evaluated for enzyme inhibition of α-glucosidase. Analogs synthesized using the Dakin oxidative method displayed stronger activity than the pristine usnic acid (IC50 >200 μM). Methyl (2E,3R)-7-acetyl-4,6-dihydroxy-2-(2-methoxy-2-oxoethylidene)-3,5-dimethyl-2,3-dihydro-1-benzofuran-3-carboxylate (6b) and 1,1'-(2,4,6-trihydroxy-5-methyl-1,3-phenylene)di(ethan-1-one) (6e) were more potent than an acarbose positive control (IC50 93.6±0.49 μM), with IC50 values of 42.6±1.30 and 90.8±0.32 μM, respectively. Most of the compounds synthesized from the benzylidene series displayed promising activity. (9bR)-2,6-Bis[(2E)-3-(2-chlorophenyl)prop-2-enoyl]-3,7,9-trihydroxy-8,9b-dimethyldibenzo[b,d]furan-1(9bH)-one (1c), (9bR)-3,7,9-trihydroxy-8,9b-dimethyl-2,6-bis[(2E)-3-phenylprop-2-enoyl]dibenzo[b,d]furan-1(9bH)-one (1g), (9bR)-2-acetyl-6-[(2E)-3-(2-chlorophenyl)prop-2-enoyl]-3,7,9-trihydroxy-8,9b-dimethyldibenzo[b,d]furan-1(9bH)-one (2d), (9bR)-2-acetyl-6-[(2E)-3-(3-chlorophenyl)prop-2-enoyl]-3,7,9-trihydroxy-8,9b-dimethyldibenzo[b,d]furan-1(9bH)-one (2e), (6bR)-8-acetyl-3-(4-chlorophenyl)-6,9-dihydroxy-5,6b-dimethyl-2,3-dihydro-1H-[1]benzofuro[2,3-f][1]benzopyran-1,7(6bH)-dione (3e), (6bR)-8-acetyl-6,9-dihydroxy-5,6b-dimethyl-3-phenyl-2,3-dihydro-1H-[1]benzofuro[2,3-f][1]benzopyran-1,7(6bH)-dione (3h), (6bR)-3-(2-chlorophenyl)-8-[(2E)-3-(2-chlorophenyl)prop-2-enoyl]-6,9-dihydroxy-5,6b-dimethyl-2,3-dihydro-1H-[1]benzofuro[2,3-f][1]benzopyran-1,7(6bH)-dione (4b), and (9bR)-6-acetyl-3,7,9-trihydroxy-8,9b-dimethyl-2-[(2E)-3-phenylprop-2-enoyl]dibenzo[b,d]furan-1(9bH)-one (5c) were the most potent α-glucosidase enzyme inhibitors, with IC50 values of 7.0±0.24, 15.5±0.49, 7.5±0.92, 10.9±0.56, 1.5±0.62, 15.3±0.54, 19.0±1.00, and 12.3±0.53 μM, respectively.

Alkaloids represent a major group of natural products (NPs), derived from highly diverse organisms. These structurally varied specialized metabolites are widely used for medicinal purposes and also known as toxic contaminants in agriculture and dietary supplements. While the detection of alkaloids is generally facilitated by GC- or LC-MS, these techniques do require considerable efforts in sample preparation and method optimization. Bypassing these limitations and also reducing experimental time, matrix-free laser desorption ionization (LDI) and related methods may provide an interesting alternative. As many alkaloids show close structural similarities to matrices used in matrix-assisted laser desorption ionization (MALDI), they should ionize upon simple laser irradiation without matrix support. With this in mind, the current work presents a systematic evaluation of LDI properties of a wide range of structurally diverse alkaloids. Facilitating a direct comparison between LDI and ESI-MS fragmentation, all tested compounds were further studied by electrospray ionization (ESI). Moreover, crude plant extracts of Atropa belladonna, Cinchona succirubra, and Colchicum autumnale were analyzed by LDI in order to evaluate direct alkaloid detection and dereplication from complex mixtures. Finally, dose-dependent evaluation of MALDI and LDI detection using an extract of Rosmarinus officinalis spiked with atropine, colchicine, or quinine was conducted. Overall, present results suggest that LDI provides a versatile analytical tool for analyzing structurally diverse alkaloids as single compounds and from complex mixtures. It may further serve various potential applications ranging from quality control to the screening for toxic compounds as well as the build up of MS databases. Graphical abstract.

Chemical investigation of the lichen Parmotrema tsavoense led to the isolation of 5 new depsidones, parmosidones F – J (1 – 5). These compounds were structurally elucidated using spectroscopic methods including HRESIMS and 2D NMR data. Compounds 1, 3, and 4 were evaluated for their inhibition of α-glucosidase. All exhibited potent α-glucosidase inhibitory activity with IC50 values ranging from 10.7 to 17.6 µM, which was much lower than that of the positive control acarbose (IC50 449 µM).

Two new lindenane sesquiterpenes were obtained from the roots of Lindera myrrha. These compounds were structurally elucidated by HRMS data, extensive NMR analyses, and comparison between experimental and theoretical 13C-NMR data. Myrrhalindenane A is the first monomeric seco-d lindenane displaying a non-rearranged, cyclohexanic C-ring. Myrrhalindenane B is the second occurrence of an angular lindenane-sesquiterpene related to a C6-C7 lactonization.

A series of novel N-substituted hydrazide derivatives were synthesized by reacting atranorin, a compound with a natural depside structure (1), with a range of hydrazines. The natural product and 12 new analogues (2–13) were investigated for inhibition of α-glucosidase. The N-substituted hydrazide derivatives showed more potent inhibition than the original. The experimental results were confirmed by docking analysis. This study suggests that these compounds are promising molecules for diabetes therapy. Molecular dynamics simulations were carried out with compound 2 demonstrating the best docking model using Gromac during simulation up to 20 ns to explore the stability of the complex ligand-protein. Furthermore, the activity of all synthetic compounds 2–13 against a normal cell line HEK293, used for assessing their cytotoxicity, was evaluated.

International audience; Three new xanthone dimers, eumitrins C - E (1-3), along with a new depsidone, 3'-O-demethylcryptostictinolide (4) were isolated from the acetone extract of the whole thallus of the lichen Usnea baileyi collected in Vietnam. Their structures were unambiguously established by spectroscopic analyses (HRESIMS, 1D and 2D NMR), as well as comparison to literature data. The absolute configurations of 1-3 were elucidated through electronic circular dichroism (ECD) analyses. The absolute configuration of 2 was validated by comparison between experimental and TDDFT-calculated ECD spectra while that of 3 was based on DFT-NMR calculations and subsequent DP4 probability score. The antiparasitic activities against Plasmodium falciparum as well as the cytotoxic activity against seven cell lines were determined for the new compounds 1-3, and led from null to mild bioactivities.

Three new phenolic compounds, peruvinides A-C were isolated from the lichen Ramalina peruviana Ach. (Ramalinaceae). Their structures were unambiguously determined by extensive spectroscopic analyses and comparison with literature data. Peruvinides A and B bearing unusual moieties were found for the first time among lichen metabolites.

Further phytochemical investigation on P. tsavoense led to one new meta-depsidone, parmosidone K together with one known compound, barbatic acid. Their structures were determined by 1D and 2D NMR analysis, high resolution mass spectroscopy, and comparison their NMR data with those reported in literatures. Parmosidone K was evaluated for α-glucosidase inhibition and revealed the powerful activity with IC50 value of 3.12 µM.

A series of lupeol derivatives 2, 2a-2f, 2a-2h, 3a-3e, and 4a-4b were designed, synthesised and evaluated for their α-glucosidase inhibitory and cytotoxic activities. Among synthetic derivatives, lupeol analogues 2b and 2e containing a benzylidene chain exhibited the best activity against α-glucosidase and superior to the positive agent with the IC50 values of 29.4 ± 1.33 and 20.1 ± 0.91 μM, respectively. Lupeol analogues 2d and 3a showed weak cytotoxicity against K562 cell line with the IC50 values of 76.6 ± 2.40 and 94.4 ± 1.51 μM, respectively.

From the leaves of Ricinus communis Linn., one new alkaloid, named ricicomin A (1) together with three known ones, ricinine (2), N-demethylricinine (3) and 4-[2-formyl-5-(methoxymethyl)-1H-pyrrol-1-yl]butanoic acid (4) were justified by repeated chromatographic methods. Their structures were determined by comprehensive IR, HR-ESI-MS and NMR analyses. Compound 4 was identified for the first time from the genus Ricinus. DFT-NMR chemical shift calculations and subsequent DP4+ probability methods were applied to confirm the chemical structure of 1. Compounds 1–3 did not display cytotoxic effect against three human cancer cell lines (MCF-7, HepG2 and HeLa) using SRB assay.

A novel oxime polyketide, maydisone (1), along with two known compounds, 7-hydroxy-2,5-dimethylchromone (2) and 2,5-dimethylbenzoic acid (3) were isolated from the cultures of Bipolaris maydis. Their structures were identified by the application of NMR and MS data analyses and comparison with previous reports. Compound 1 showed the most powerful inhibition of α-glucosidase, with an IC50 value of 68.30 ± 0.83 µM.

A novel bixanthone, named schomburgkixanthone (1), was isolated from the twigs of Garcinia schomburgkiana, along with six known compounds, griffipavixanthone (2), 4-hydroxyxanthone (3), 2-hydroxyxanthone (4), 1,6-dihydroxyxanthone (5), 1,7-dihydroxyxanthone (6), and 1,3,5-trihydroxyxanthone (7). The structure of 1 was identified by the application of NMR and MS data analyses and comparison with previous reports. Compound 1 showed the most powerful inhibition of rat intestinal α-glucosidase, with IC50 values of 0.79 for maltase and 1.81 mM for sucrase. Compound 2 most strongly inhibited sucrase, with an IC50 value of 4.58 mM.

Chemical investigation of the lichen Parmotrema dilatatum led to the isolation of a new chlorinated compound, named dilatatone (1), along with a known compound, sernanderin (2). Their chemical structures were determined by analysis of their 1 D and 2 D NMR spectra, HRESIMS, and ECD data. Both compounds showed weak α-glucosidase inhibitor activity.

Twelve benzylidene derivatives, one Baeyer-Villiger oxidative, six imine derivatives were successfully designed and synthesised from phyllanthone. In the search for potential new anti-diabetic agents, phyllanthone along with its benzylidene and oxidation analogues were evaluated for enzyme inhibition against α-glucosidase. In the benzylidene series, most analogues displayed stronger activity than the mother compound. Compound 1c revealed the strongest activity, outperforming the acarbose positive control with an IC50 value of 19.59 µM. Phyllanthone and its derivatives were then tested for cytotoxic activity against the K562 cell line. The imine analogues displayed the most powerful cytotoxic activity with 3cand 3d having IC50 values of 57.55 and 68.02 µM, respectively.

Chemical investigation of the lichen Parmotrema tinctorum (Nyl.) Hale led to the isolation of two new phenolic compounds, 2-ethylhexyl orsellinate (1) and tinctorinone (2). The structures were determined by analysis of their MS and NMR data as well as by comparison with literature data. The 2-ethylhexyl ester group of 2-ethylhexyl orsellinate is uncommon among lichen metabolites. Tinctorinone revealed strong inhibition towards α-glucosidase.

Investigation of the chemical constituents of the lichen Usnea baileyi (Stirt.) Zahlbr led to the isolation of a new dimeric xanthone, bailexanthone (1), and a novel depsidone, bailesidone (2), along with twenty-five known metabolites (3–27). Their structures were established by means of extensive spectroscopic analysis and comparison with data reported in the literatures. Compound 1 derives from secalonic acid scaffold with C-8/8′ reduction and compound 2 represents the first example of menegazziaic acid derivative with an unprecedented B-ring moiety. Two new compounds 1–2 were evaluated for their cytotoxic activities against A549 (human lung carcinoma) and HT29 (human colorectal adenocarcinoma) cell lines. All of them showed weak or no activity against two cell lines.

International audience; Two novel diterpenes, phyllanes A and B, were isolated from the roots of Phyllanthus acidus, along with the cleistanthane diterpene, spruceanol. Their chemical structures were unambiguously elucidated by extensive 1D and 2D NMR analyses and high resolution mass spectroscopic data, as well as by comparison with literature data. While phyllanes A and B are respectively reminiscent of amphilectane and serrulatane diterpenoids, their highly unusual substitution patterns and their co-occurrence with spruceanol led us to assume that they might correspond to an unprecedented type of re-arranged cleistanthane-diterpenoid precursors, resulting in final products that display a unique scaffold among terrestrial diterpenoids. Accordingly, a possible biosynthetic route to the two new compounds from the readily accessible spruceanol is proposed herein. These two compounds were evaluated for their cytotoxic activities against two cancer cell lines. Only phyllane B exerted a moderate activity against K562 and HepG2 cell line with IC50 values of 28.90 and 45.23 μg/mL, respectively. © 2017

Two new cycloartane glycosides, nervisides I&ndash, J, were isolated from Nervilia concolor whole plants. Their structures were unambiguously established by interpretation of their HRESIMS and 1D and 2D NMR data. These cycloartanes comprised a stereogenic center at C-24, the R configuration of which was assigned based on DFT-NMR calculations and the subsequent DP4 probability score. These compounds were tested for cytotoxicity against K562 and MCF-7 tumor cell lines, revealing mild cytotoxic activity.

International audience; The phytochemical investigation of Euphorbia tirucalli L. (Euphorbiaceae) yielded four new compounds, including a rare cadalene-type sesquiterpene (tirucadalenone), two tirucallane triterpenoids, euphorol L and euphorol M, with the latter being described as an epimeric mixture, and a euphane triterpene, namely, euphorol N, together with 7 known compounds. Their structures and absolute configurations were elucidated from analysis of 1D (1H, J-modulated C) and 2D NMR (HSQC, HMBC and NOESY), high-resolution mass spectrometry (HRESIMS), optical rotation, and GIAO NMR shift calculation followed by CP3 analysis, along with comparison with literature reports. All these compounds were tested for cytotoxicity against K562, MCF-7 and/or and HepG2 tumor cell lines. Only tirucadalenone displayed a mild cytotoxic activity.

A phytochemical investigation of the foliose lichen Parmotrema tsavoense (Krog and Swinscow) Krog and Swinscow (Parmeliaceae) resulted in the isolation of a new trichlorinated xanthone, isodemethylchodatin. The structure elucidation of this new norlichexanthone derivative proved tricky owing to proton deficiency, and to the lack of NMR data of closely related analogues. The structure of this compound was determined based on an integrated interpretation of 13C-NMR chemical shifts, MS spectra, and DP4-based computational chemistry was also performed to provide an independent and unambiguous validation of the determined structure. Isodemethylchodatin represents the first chlorinated lichexanthone/norlichexanthone derivative bearing a methoxy group at C-5.

Five naphthoquinones including 4 compounds with new absolute configurations, (–)-2' S-trypethelone methyl ether (1), (–)-2' S-8-methoxytrypethelone methyl ether (2), (–)-(2' S,3' S)-4'-hydroxytrypethelone (3), and (–)-(2' S,3' R)-4'-hydroxy-8-methoxy trypethelone methyl ether (5), together with a known compound, (–)-2' S-trypethelone (4), were isolated from cultured mycobiont of Marcelaria cumingii. These compounds were structurally elucidated by high-resolution mass spectra, nuclear magnetic resonance, circular dichroism, optical rotation, and single-crystal X-ray analysis. The cytotoxicity against several cancer cell lines of the isolated compounds were tested. (–)-2' S-Trypethelone methyl ether (1) showed selective inhibition of HCT116 and A549 cell lines with half-maximal inhibitory concentration values of 0.32 ± 0.03 and 1.05 ± 0.12 µM, respectively. The binding conformation and molecular interactions including the effect of substituent modification were also revealed.

Two new triterpenes, the seco-friedelane type secofriedelanophyllemblicine and the ursane-derived saponin ursophyllemblicoside were isolated from the roots of the edible fruit-producing Phyllanthus emblica. Their structures were unambiguously elucidated using extensive 1D and 2D NMR analyses, high resolution mass spectrometry and single-crystal X-ray crystallographic analyses along with comparison with literature data. Secofriedelanophyllemblicine represents the first 3,4-secofriedelane bearing a carboxylic acid group substituent at C-20. Ursophyllemblicoside, incorporating the rare 21α hydroxyursolic acid as a sapogenol represents the first example of saponin comprising this aglycone. Secofriedelanophyllemblicine displayed a moderate cytotoxicity against K562 and HepG2 cancer cell lines.

International audience; New racemic dispiranic polyketides, tsavoenones A (1), B (2) and C (3), having a novel 1,7-dioxadispiro[4.0.4.4]tetradecane scaffold were isolated from the foliose lichen Parmotrema tsavoense. These compounds were structurally elucidated by extensive NMR analyses, comparison between experimental and theoretical 13C NMR data and X-ray crystallography. A putative biosynthetic scenario for the formation of 1-3 from parmosidone D, a meta-depsidone previously isolated from the same lichen material, was proposed. Tested for its cytotoxicity, 1 displayed a moderate activity against human myelogenous leukemia K562 cell line with an IC50 value of 66 μg mL-1. © 2018 The Royal Society of Chemistry.

International audience; Six new sulfonic acid-containing flavonoids, acidoflavanone (1), acidoauronol (2), 5- O-methylacidoauronol (3), acidoaurone (4), acidoisoflavone (5), and acidoflavonol (6), were isolated from the EtOH extract of the roots of Phyllanthus acidus. Their structures were unambiguously established by interpretation of their HRESIMS and 1D and 2D NMR data, single-crystal X-ray diffraction analysis, and comparison to the literature data. These new structures represent the first examples of sulfonic acid-containing flavanones, auronols, aurones, and isoflavones.

International audience; Chemical investigation of the methanol extract of the fertile form of Roccella montagnei collected in Vietnam afforded twelve secondary metabolites, including five new montagnetol derivatives, orsellinylmontagnetols A-D and a furanyl derivative together with seven known compounds. Their chemical structures were elucidated by analysis of 1D and 2D NMR and high resolution mass spectroscopic data. The relative stereochemistry of two chiral centers (C-2 and C-3) of orsellinylmontagnetols A and B was elucidated by comparison of their coupling constants and the specific rotation with those reported in the literature while the absolute stereochemistry was determined by the application of a modified Mosher method for the hydroxy group at C-3. The absolute configuration (2R,3S) of the butanetetraol moiety of these compounds is in accordance with that of erythrin, a recognized chemotaxonomic marker of the genus Roccella. Five of these compounds were evaluated for their cytotoxic activities against four cancer cell lines. Only orsellinylmontagnetol A exerted a moderate activity against MCF-7 cell line with an IC50 value of 68.39 ± 3.46 μM.

A new compound, namely hopane-6 α,16 α,22-triol (1), along with 8 known compounds 2 to 9, leucotylin (2), 16 β-acetoxyhopane-6 α,22-diol (3), 6 α-acetoxyhopane-16 β,22-diol (4), zeorin (5), 6 α-acetoxyhopane-22-ol (6), ergosterol peroxide (7), brassicasterol (8), and atranorin (9), was isolated from the lichen Parmotrema sancti-angelii. The structures of all the isolated compounds 1 to 9 were fully characterized using spectroscopic data, as well as comparison with the previous literature data. Moreover, compounds 2 and 4 were assessed for their in vitro cytotoxicity against 3 human cancer cell lines.