Abstract: Two new diastereoisomeric saponins named as Julibroside J₁₄and Julibroside J₁₅were isolated from the dried stem barks of Albizia julibrissin. On the basis of chemical and spectral methods, their structures were elucidated as 3-O-[β-D-xylopyranosyl-(1→2)-β-Darabinonosyl-(1→6)-β-D-glucopyranosyl]-21-O-｛ (6S)-2-trans-2,6-dimethyl-6-O-[4-O-((6R)-2-trans-2,6-dimethyl-6-O-β-D-quinovopyranosyl-2,7-octadienoyl)-β-D-quinovopyranosyl]-2,7-octadienoyl｝ acacic acid 28-O-β-D-glucopyranosyl-(1→3) [α-L-arabinofuranosyl-(1→4)]-α-Lrhamnopyranosyl-(1→2)-β-D-glucopyranosyl ester (1) and 3-O-[β-Dxylopyranosyl-(1→2)-β-D-arabinopyranosyl-(1→6)-β-D-glucopyranosyl]-21-O-｛(6S)-2-trans-2,6-dimethyl-6-O-[4-O-((6S)-2-trans-2,6-dimethyl-6-O-β-D-quinovopyranosyl-2,7-octadienoyl)-β-D-quinovopyranosyl]-2,7-octadienoyl｝ acacic acid 28-O-β-D-glucopyranosyl-(1→3)-[α-Larabinofuranosyl-(1→4)]-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl ester(2), respectively.

Key words: Leguminousae, Albizia julibrissin, Triterpenoid saponins, Diastereoisomerism, Julibroside J₁₄, Julibroside J₁₅