No abstract

Plumbagin, a naphtoquinone compound was isolated from Plumbago Capensis (Plumbaginaceae), an East African medicinal plant. This compound exhibited relatively specific antimicrobial activity against yeasts and potent insect antifeedant activity against the larvae of African arrny worms.

Chemical study of four samples of Ligularia brassicoides collected in Sichuan Province of China afforded 18 compounds, five of which were new. LC-MS profiles were somehow similar to each other, although the compound ratio was slightly different. One of the new compound was a Diels-Alder adduct between franoeremophilan-10-ol and methacrylic acid.

Root constituents of Ligularia longihastata were examined for the first time. Fourteen eremophilane sesquiterpenes, including two new eremophilanes identified as 3-isobutyroyloxy-7H-eremophila-9,11-dien-8-one and 3-angeloyloxy-1,10-epoxyfuranoeremophilan-9-one, and three eudesmanes were isolated. From samples collected in Baiyu County, Sichuan Province, furanoeremophilane derivatives were isolated, while various eremophilan-8-ones were isolated from samples collected in Kangding County, Sichuan. The results suggest chemical diversity in the species.

The chemical constituents of Ligularia wilsoniana were studied for the first time, using four samples collected in Chongqing City, China. Two new compounds, 6-(2',3'-epoxy-2'-methylpropanoyloxy)-1,10-epoxyfuranoeremophilane and 11H-6-(2'-hydroxymethylacryloyloxy)-1,10;7,8diepoxyeremophilanolide, as well as eight known compounds, were isolated from one of the samples, while three to four known furanoeremophilanes were isolated from the other three samples. No compound was common to the two classes of the samples, demonstrating the presence of at least two chemotypes of this species.