Two new quassinoids, javanicolides C and D, and five new quassinoid glucosides, javanicosides B-F, were isolated from the seeds of Brucea javanica, along with eight known quassinoids, i.e., yadanziolides A, C, D, and S, bruceins D and E, brusatol, and the aglycone of yadanzioside D, and 19 known quassinoid glucosides, i.e., yadanziosides A-G, I, and K-P, bruceosides A-C and E, and bruceantinoside A. Their structures were elucidated by analysis of spectroscopic data and chemical evidence.
Hesperidin (2S-form), the flavanone 7-O-glycoside, is the main constituent of some Citrus species. The peels of two Citrus species are used as a crude drug, Aurantii nobilis pericarpium, in the Japanese Pharmacopoeia and as components in Kampo formulae. Thus, HPLC analysis of hesperidin as a marker compound is needed for quality control of medicines. Hesperidin was separated from the corresponding C-2 epimer by normal-phase HPLC using a chiral column. Moreover, narirutin and neohesperidin were also separated from the corresponding C-2 epimer. The analyses of commercial hesperidin samples revealed that they contained the C-2 epimer and that the relative ratio of hesperidin to the epimer ranged from 92:8 to 59:41. The HPLC application to Citrus extracts suggested that naturally occurring hesperidin in Citrus has the 2S configuration; however, the dry extracts of rikkunshito and chotosan, which are Kampo formulations containing Aurantii nobilis pericarpium, were found to contain a considerable amount of the (2R)-epimer. These data suggest that the decoction process of the formulae partly converts hesperidin to the epimer. Because diastereomers differ from each other in physicochemical and biological activities, HPLC to separate hesperidin from the C-2 epimer should be introduced into the letter of approval for herbal medicines.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.