Isolation of Aloinoside B and Metabolism by Rat Intestinal Bacteria

AbstractA compound was isolated from South African Cape aloes, and the structure was elucidated as 10-glucopyranosyl-1, 8-dihydroxy-3-(rhamnopyranosyl-hydroxymethyl)-9(10H.)-anthracenone (named aloinoside B) on the basis of various spectroscopic evidence (IR, MS, 1H NMR, 13C NMR, HMQC, HMBC, 1H–1H COSY). Aloinoside B was metabolized to barbaloin, isobarbaloin, and a hydroxyl metabolite by rat intestinal bacteria. The peak amount of barbaloin was reached about 3 h after oral administration.