Flavonol glycosides from the aerial parts of Aceriphyllum rossii and their antioxidant activities.

The methanol extract obtained from the aerial parts of Aceriphyllum rossii (Saxifragaceae) was fractionated into ethyl acetate (EtOAc), n-BuOH and H2O layers through solvent fractionation. Repeated silica gel column chromatography of EtOAc and n-BuOH layers afforded six flavonol glycosides. They were identified as kaempferol 3-O-beta-D-glucopyranoside (astragalin, 1), quercetin 3-O-beta-D-glucopyranoside (isoquercitrin, 2), kaempferol 3-O-alpha-L-rhamnopyranosyl (1-->6)-beta-D-glucopyranoside (3), quercetin 3-O-alpha-L-rhamnopyranosyl (1-->6)-beta-D-glucopyranoside (rutin, 4), kaempferol 3-O-[alpha-L-rhamnopyranosyl (1-->4)-alpha-L-rhamnopyranosyl (1-->6)-beta-D-glucopyranoside] (5) and quercetin 3-O-[alpha-L-rhamnopyranosyl (1-->4)-alpha-L-rhamnopyranosyl (1-->6)-beta-D-glucopyranoside] (6) on the basis of several spectral data.

13-Hydroxy-9Z,11E,15E-octadecatrienoic acid from the leaves of Cucurbita moschata.

A new unsaturated hydroxy fatty acid was isolated from the leaves of Cucurbita moschata through repeated silica gel column chromatography and chemical methods. The structure of the new fatty acid was determined as 13-hydroxy-9,11,15-octadecatrienoic acid on the basis of several spectral data including 2D-NMR. The stererostructures of double bonds were determined to be 9Z, 11E and 15E by coupling patterns of related proton signals in the 1H-NMR and NOESY experiments.

Aceriphyllic acid A, A new ACAT inhibitory triterpenoid, from Aceriphyllum rossii.

Two new triterpenoids along with three known ones, 3-oxoolean-12-en-27-oic acid (1), 3alpha-hydroxyolean-12-en-27-oic acid (2) and 3beta-hydroxyolean-12-en-27-oic acid (3), were isolated from Aceriphyllum rossii. The structures of the new compounds were determined to be a 3alpha,23-dihydroxyolean-12-en-27-oic acid (4) and a 3alpha,23-dihydroxyolean-12-en-29-oic acid (5) by spectroscopic and chemical methods; they were designated aceriphyllic acids A and B, respectively. Compounds 2, 3 and 4 remarkably inhibited the activity of ACAT.