Dammarane-type triterpene saponins from the roots of Panax notoginseng (Burk.) F. H. Chen and their neuroprotective effects.

Three undescribed dammarane-type triterpene saponins, 20(S)-sanchirhinoside A7-A9 (1-3), together with seventeen known ones, were isolated from the roots of Panax notoginseng (Burk.) F. H. Chen. The chemical structures of the new compounds were determined by HR-MS and NMR experiments along with chemical methods. To the best of our knowledge, compound 1 was the firstly reported fucose-containing triterpene saponin from plants in the genus of Panax. Moreover, the in vitro neuroprotective effects of the isolated compounds were evaluated. Compounds 11-12 displayed remarkable protective effects against PC12 cells injured by 6-hydroxydopamine.

Phytochemical characterisation of an important medicinal plant, Chenopodium ambrosioides Linn.

The project was intended to the phytochemical characterisation from the rudimentary methanolic extract of Chenopodium ambrosioides Linn., which escorts to the isolation of stigmasterol (1), ß-sitosterol (2), octadecanoic acid (3), scopoletin (4) and 1-piperoylpiperidine (5). Literature validates the medicinal authentication of these compounds extorted from other sources, while our previous findings regarding microbial activities of different solvent systems fractions are favouring the presence of medicinally important compounds in this species. Herein, however, we report these natural products for the first time from this species.

Homo-aro-cholestane, furostane and spirostane saponins from the tubers of Ophiopogon japonicus.

Phytochemical investigation of the tubers of Ophiopogon japonicus led to the isolation of five previously undescribed steroidal saponins, ophiojaponins A-E, together with twelve known ones. The structures of these isolated compounds were elucidated by detailed spectroscopic analyses and chemical methods. Ophiojaponins A-C are rare naturally occurring C29 steroidal glycosides possessing a homo-cholestane skeleton with an aromatized ring E. Ruscogenin 1-O-α-L-rhamnopyranosyl-(1 â†’ 2)-4-O-sulfo-ß-D-fucopyranosido-3-O-ß-D-glucopyranoside was isolated as single component and its full spectroscopic data was reported for the first time. The isolated steroidal saponins were evaluated for their cytotoxicities against two human tumor cell lines MG-63 and SNU387. Among them, five known spirostane-type glycosides showed cytotoxic activity against both MG-63 and SNU387 cell lines with IC50 values ranging from 0.76 to 27.0 µM.

A new irregular monoterpene acetate along with eight known compounds with antifungal potential from the aerial parts of Artemisia incisa Pamp (Asteraceae).

A new compound named as santolinylol-3-acetate (4-(2-hydroxypropan-2-yl)-2-methylhexa-1,5-dien-3-yl acetate) (3), along with seven known compounds; linoleic acid (1), benzoic acid (2), santolinylol (4), ethyl-(E)-p-hydroxy cinnamate (5), scopoletin (6), esculetin (7) isofraxidin (8) and eupatorin (9), were isolated from the aerial parts (ethanolic extract) of endangered species: Artemisia incisa Pamp (Asteraceae). The compounds' structures were determined through modern spectroscopic techniques, and comparison of data (physicochemical constants) with the literature. The relative stereochemistry of santolinylol-3-acetate (3) was determined by comparing its data of NOESY, and specific rotation with its diol analogue; santolinylol (4), isolated from the same plant; A. incisa. The results of the antifungal activity showed that coumarins are as whole less active compounds. Compounds 3 (25 and 300 µg/mL), and 4 (12.5 and 300 µg/mL), showed good activities against Candida albicans, and Aspergillus flavus, respectively, which justifies A. incisa as a traditional medicine for curing the said fungal infections.

Isolation, structure elucidation and enzyme inhibition studies of a new hydroxy ester and other compounds from Berberis jaeschkeana Schneid stem.

Bioassay-guided isolation and fractionation of Berberis jaeschkeana Schneid var. jaeschkeana stem resulted in the isolation and characterisation of a new long chain hydroxy ester named as berberinol (1) along with six known compounds (2-7). All the structures were established from 1D and 2D spectroscopic data. Crude extract, sub-fractions and all the isolated compounds were evaluated for their anti-fungal and urease enzyme inhibition properties. All of the sub-fractions and compounds showed good anti-fungal and urease enzyme inhibition properties. Minimum inhibitory concentrations (MICs) were calculated for all active samples in case of urease enzyme inhibition. MICs values were found to be in the range of 39.03-49.78 µg/mL for urease enzyme inhibition.

Neolignans, lignans and glycoside from the fruits of Melia toosendan.

Four new neolignans, meliasendanins A-D (1-4), and a new glycoside, toosenoside A (5), together with ten known ones (6-15), were isolated from a n-BuOH partition of the fruits of Melia toosendan. Their structures were elucidated by analyses of extensive spectroscopic data and comparison of the NMR data with those reported previously. Meliasendanin A (1) was a rare neolignan containing isochroman moiety, and its absolute configuration was determined using a CD spectrum. Toosenoside A (5) was an unusual glycoside with a rare naturally occurring aglycone and its structure was confirmed by X-ray single crystal diffraction analysis. The antioxidant activity of the isolated neolignans and lignans was evaluated by ABTS radical-scavenging assay. Compounds 1 and 13 exhibited strong antioxidant activity, with IC50 values of 62.8 and 45.1 µM, respectively.