NOVEL HIGHLY SWEET SECODAMMARANE GLYCOSIDES FROM PTEROCARYA-PALIURUS

Two novel, potently sweet 3,4-secodammaranoid saponins designated pter ocaryosides A (1) and B (2) have been isolated from the leaves and ste ms of the Chinese tree Pterocarya paliurus. The structures of these co mpounds were established as ,25-trihydroxy-3,4-secodammara-4(28),23-di en-3-oic acid 12-O-beta-D-quinovopyranoside and ,25-trihydroxy-3,4-sec odammara-4(28),23-dien-3-oic acid 12-O-alpha-L-arabinopyranoside, on t he basis of spectroscopic measurements, especially 1D and 2D NMR data. The methylated peracetates of pterocaryosides A and B were prepared a nd used for structural confirmation. Preliminary evaluations constitut ed by mouse acute toxicity and bacterial mutagenesis determinations su pported the safety of 1 and 2, and subsequently the compounds were rat ed by a human taste panel as about 50 and 100 times sweeter than 2% su crose, respectively.