Iminosugar-producing Thai medicinal plants

alpha-1-C-Hydroxymethylfagomine (7), 3-O-beta-D-glucopyranosyl-DMDP (12), and 2,5-dideoxy-2,5-imino-Dglucitol (13) were isolated from the Thai traditional crude drug Non tai yak (Stemona tuberosa), which also contains a high concentration level of a-homonojirimycin (0.1% dry weight). Thopthaep (Connarus ferrugineus) and Cha em thai (Albizia myriophylla) contained 1-deoxymannojirimycin (DMJ) (10) at levels of 0.083% (dry weight) and 0.17% (dry weight), respectively. 2-O-alpha-D-Galactopyranosyl-DMJ (20), 3-O-beta-D-glucopyranosyl-DMJ (21), 1,4-dideoxymannojirimycin (17), 1,4-dideoxyallonojirimycin (18), and 1,4-dideoxyaltronojirimycin (19) from C. ferrugineus and 2-O-beta-D-glucopyranosyl-DMJ (22) and 4-O-beta-Dglucopyranosyl-DMJ (23) from A. myriophylla were isolated as new compounds.