Newbouldiosides A-C, phenylethanoid glycosides from the stem bark of Newbouldia laevis

摘要

From the stem bark of Newbouldia laevis three phenylethanoid glycosides, designated as newbouldioside A-C, were isolated together with a sodium salt of analogue B and the known compounds, verbascoside, 5-hydroxydehydro-iso-alpha-lapachone, 3,8-dihydroxydehydro-iso-alpha-lapachone, apigenin and luteolin. The structures of the phenylethanoid glycosides were elucidated by spectroscopic methods as ss-(3,4-dihydroxyphenyl)ethyl 5-O-syringoyl-ss-d-apiofuranosyloxy-(1-->2)-O-[alpha-l-rhamnopyranosyl-(1- ->3)]-ss-d-glucopyranoside, ss-(3,4-dihydroxyphenyl)ethyl 5-O-syringoyl-ss-d-apiofuranosyloxy-(1-->2)-O-[alpha-l-rhamnopyranosyl-(1- ->3)]-6-O-E-feruloyl-ss-d-glucopyranoside, and ss-(3,4-dihydroxyphenyl)ethyl 3-O-E-feruloyl-ss-d-apiofuranosyloxy-(1-->2)-O-alpha-l-rhamnopyranosyl-(1- ->2)-6-O-E-sinapoyl-ss-d-glucopyranoside, respectively.