Two New Spirostanol Glycosides fromCestrum parqui

Abstract

Two new steroidal glycosides, parquisoside A (1) and B (2) were isolated from the aerial parts of Cestrum parqui (family Solanaceae). Their common aglycone is a new steroid of the spirostane series, which we name parquigenin. It has the structure (3β,24S,25S)-spirost-5-ene-3,24-diol, i.e. a (24S,25S)-24-hydroxydiosgenin. The structures of parquisosides A and B were elucidated as (3β,24S,25S)-spirost-5-ene-3,24-diol 3-O-{[α-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→4)}-β-D-glucopyranoside (1) and (3β,24S,25S)-spirost-5-ene-3,24-diol 3-O-{[α-L-rhamnopyranosyl)-(1→4)-α-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→4)}-β-D-glucopyranoside (2), respectively, on the basis of detailed spectroscopic studies and chemical analysis. The crude extract of Cestrum parqui showed inhibition of carrageenin-induced edema.