A new cucurbitane - type triterpenoid from the bark of Kurz.

A new cucurbitacin, 3-(-D-glucopyranosyloxy)-5,6:16,23-diepoxycucurbit-24-en-11-one or hygrocucurbin A , along with two known compounds, including 3-(-D-glucopyranosyloxy)-16,23-epoxycucurbita-5,24-dien-11-one and (+)-lyoniresinol , were isolated from the bark of . Their chemical structures were elucidated by spectroscopic NMR, HR-IDA- TOF-MS analysis, and by comparison with the spectral data of corresponding compounds in the literature. Two cucurbitacins and were evaluated for their -glucosidase inhibitory activity and cytotoxic against KB, MCF-7, Hep G2, and A549 cancer cell lines.

Comtrifosides A and B, two new triterpenoid saponins from the leaves of .

The phytochemical composition of the leaves was studied for the first time. Two new triterpenoid saponins, named comtrifoside A () and comtrifoside B (), together with two other saponins () were purified by variously chromatographic techniques. For the first time, compound was informed from the genus, as well as all of the isolated compounds () were reported from .

Spermacosides a and B, two new triterpenoid saponins from burm.f.

Two new triterpenoid saponins, named spermacosides A-B (-), together with two known oleanane-type triterpenoid saponins, 3--D-xylopyranosyl-(1→3)-D-glucopyranosylbayogenin ( and 3---D-glucopyranosylbayogenin (), were isolated from the ethyl acetate extract of Burm.f. in a phytochemical investigation.

Jasminanthoside - a new pregnane-steroid from .

A new pregnane steroid, jasminanthoside (), together with three known compounds, telosmoside A7 (), syringaresinol (), and methyl 6-deoxy-3--methyl--D-allopyranosyl-(1→4)--D-oleandropyranoside () were isolated from the ethyl acetate extract of roots collected in Vietnam. Their chemical structures were elucidated by NMR and MS spectroscopic data analysis along with the comparison of their data with the published ones in the literature. Although was a known compound, its full NMR data were reported for the first time.

Two new halogenated sesquiterpene lactones from .

Two new sesquiterpene lactones, laurenolide A () and laurenolide B (), along with six known compounds, palmitic acid (), (,)-hexahydrofarnesyl acetone (), -phytol acetate (), cholesterol (), cholesteryl acetate (), cholesteryl heptadecanoate () were isolated from . The chemical structures of all compounds were elucidated by 1D and 2D-NMR spectroscopy and HR-ESI-MS analysis as well as compared with data in the literature. The petroleum ether, chloroform, ethyl acetate, methanol extracts and compounds , were tested for the inhibition of two cancer cell lines MCF-7, NCI-H460 and they showed weak or none activities.

A and B: two new oleanane saponins from the aerial parts of .

Two new oleanane saponins, hedyocoronin A and hedyocoronin B (), were isolated from the aerial parts of (Kurz) Craib, Rubiaceae, collected at Da Oai district, Lam Dong province in Vietnam. Their chemical structures were elucidated by HR-MS, 1D and 2D-NMR spectra, along with the comparison with those reported in the literature. Compounds and showed weak cytotoxicity against KB and HeLa-S3 cancer cell lines with IC values of more than 54 µM.

Nepetifoliol - a new glutinane-triterpenoid from .

A new glutinane-triterpenoid, nepetifoliol (), together with two known compounds, dymacrin D (), and (+)-ar-tumerone () were isolated from the -hexane extract of the aerial parts of . Their chemical structures were elucidated by spectroscopic data analysis as well as the comparison of their NMR data with the ones published in the literatures. A putative biosynthetic pathway for the formation of the new compound (diaxial-5,6-diol) () from the precursor triterpene glutinol was proposed.

A new resorcinol derivative from the bark of (Primulaceae).

Chemical investigation of the Vietnamese plant Roem. & Schult. (Primulaceae) led to the isolation of the new compound 3-methoxy-5-nonylphenol () along with five known ones 2,8,10-trihydroxy-6-benzo[]chromen-6-one (), 2-hydroxy-5-methoxy-3-nonylbenzo-1,4-quinone (), 5-(3-hydroxypropyl)-7-methoxy-3-(methylbenzofuran-2-yl)-3-methoxyphenol (), 2,8-dihydroxy-7-methoxy-3,9-diundecyldibenzofuran-1,4-dione () and 10-hydroxy-4-methoxy-2,11-diundecylgomphilactone ().

Usneaceratins A and B, two new secondary metabolites from the lichen .

Two new compounds, comprising one dibenzofuran, named usneaceratin A (), and one phenolic acid, named usneaceratin B (), together with one known dibenzofuran, isousnic acid (), and two known phenolics, orsellinic acid () and methyl orsellinate () were clarified from the lichen using variously chromatographic methods. Their structures were testified by comprehensive HR-ESI-MS, and NMR spectroscopic analysis, and comparison with published data. Their -glucosidase inhibitory activity of all compounds was measured.

Two new phenolic compounds from the Vietnamese lichen .

Chemical investigation of the lichen (Nyl.) Hale led to the isolation of two new phenolic compounds, 2-ethylhexyl orsellinate () and tinctorinone (). The structures were determined by analysis of their MS and NMR data as well as by comparison with literature data.

Three new phenolic compounds from the lichen Ach. (Ramalinaceae).

Three new phenolic compounds, peruvinides A-C were isolated from the lichen Ach. (Ramalinaceae). Their structures were unambiguously determined by extensive spectroscopic analyses and comparison with literature data.

Three new diphenyl ethers from the lichen (Nyl.) Hale (Parmeliaceae).

Three new diphenyl ethers, named praesorethers E, F and G (, and ), were isolated from the lichen . Their chemical structures were elucidated on the basis of extensively spectroscopic analysis including HR-ESI-MS and NMR as well as comparison with previously published data. These compounds were evaluated for the cytotoxicity against three human cancer cell lines (HeLa, NCI-H460 and MCF-7) using SRB assay.

A new depsidone from the lichen Arch.

Chemical investigation of the lichen Arch led to the isolation of five depsidones, including one new compound ceratinalone along with four known compounds bailesidone stictic acid , 8'--methylstictic acid and 8'--ethylstictic acid . The structures were determined by analysis of their MS and NMR data as well as by comparison with literature values. Compounds and 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.

A new triterpenoid saponin from .

From the ethanol extract of , collected at Phu Yen province, Viet Nam, one new triterpenoid saponin () and four known compounds () were isolated. By means of NMR and HR-ESI-MS analyses, their structure was elucidated as 3--(β-D-xylopyranosyl-(1→3)-β-D-xylopyranosyl)spergulagenin A or glinusopposide V (), glinusopposide L (), spergulin B (), vitexin () and astralagin (). Two compounds () showed weak inhibitory activity against .

Synthesis and cytotoxic evaluation of usnic acid benzylidene derivatives as potential anticancer agents.

A series of usnic acid benzylidene derivatives (groups ) were designed, synthesized and evaluated for their anticancer activity in the search for potentially new anticancer agents. Compounds , , , and exhibited the most potent cytotoxcity against K562 cell line with IC values of 10.0 ± 3.

DP4-Assisted Structure Elucidation of Isodemethylchodatin, a New Norlichexanthone Derivative Meager in H-Atoms, from the Lichen .

A phytochemical investigation of the foliose lichen (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 C-NMR chemical shifts, MS spectra, and DP4-based computational chemistry was also performed to provide an independent and unambiguous validation of the determined structure.

Further terpenoids from Euphorbia tirucalli.

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.

Sulfonic Acid-Containing Flavonoids from the Roots of Phyllanthus acidus.

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.

Two new triterpenoids from the roots of Phyllanthus emblica.

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.

Tsavoenones A-C: unprecedented polyketides with a 1,7-dioxadispiro[4.0.4.4]tetradecane core from the lichen Parmotrema tsavoense.

New racemic dispiranic polyketides, tsavoenones A (1), B (2) and C (3), having a novel 1,7-dioxadispiro[4.0.4.

New erythritol derivatives from the fertile form of Roccella montagnei.

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.

Chemical constituents from Sonneratia ovata Backer and their in vitro cytotoxicity and acetylcholinesterase inhibitory activities.

Sonneratia ovata Backer, Sonneratiaceae, is a widespread plant in mangrove forests in Vietnam, Cambodia, Thailand, Indonesia. Sonneratia ovata's chemical composition remains mostly unknown. Therefore, we now report on the structural elucidation of three new phenolics, sonnerphenolic A (1), sonnerphenolic B (2), and sonnerphenolic C (23), a new cerebroside, sonnercerebroside (3) together with nineteen known compounds, including nine lignans (5-13), two steroids (14, 15), two triterpenoids (16, 17), three gallic acid derivatives (18-20), two phenolic derivatives (4, 22) and a 1-O-benzyl-β-d-glucopyranose (21) isolated from the leaves of Sonneratia ovata.