New dihydro-ß-agarofuran sesquiterpenes from Parnassia wightiana wall: isolation, identification and cytotoxicity against cancer cells.

Five new (4-8) and three known (1-3) dihydro-ß-agarofuran sesquiterpene polyesters were isolated from the whole plants of Parnassia wightiana. The structures of all compounds were elucidated through spectroscopic analysis including 2D-NMR and HR-MS. The absolute configuration of these compounds was established by X-ray diffraction analysis, comparison of NOESY spectra and biogenetic means. The cytotoxities of compounds 2-8 were evaluated in vitro against HL-60, SMMC-7721, A549, MCF-7 and SW480 cell lines. Compounds 5-7 exhibited the highest activities with IC50 values of 11.8-30.1 µM in most cases. The SAR revealed that the introduction of hydroxyl group was able to significantly improve the activities of the compounds for most of the cell lines.

Ergosterol peroxides as phospholipase A(2) inhibitors from the fungus Lactarius hatsudake.

Four ergosterol derivatives (1-4) have been isolated for the first time from the fruiting bodies of a basidiomycete fungus, Lactarius hatsudake, through activity-guided fractionation. Their structures were determined, using spectroscopic analysis, as: (22E,24R)-ergosta-5,7,22-dien-3beta-ol (ergosterol, 1); 5alpha,8alpha-epidioxy-(22E,24R)-ergosta-6,22-dien-3beta-ol (ergosterol peroxide, 2); 5alpha,8alpha-epidioxy-(24S)-ergosta-6-en-3beta-ol (3); and (22E,24R)-ergosta-7,22-dien-3beta,5alpha,6beta-triol (cerevisterol, 4). Compounds 2 and 3 showed selective inhibitory activity against Crotalus adamenteus venom phospholipase A(2) (PLA(2)) enzyme, but not against Apis mellifcra bee venom PLA(2). The antiphospholipase A(2) activity of compounds 2 and 3 are reported here for the first time.