A New Isomer of Julibroside J2fromAlbizia julibrissin

A new isomer of Julibroside J2 (Chen, S.P., Zhang, R.Y., Ma, L.B. and Tu, G.Z. Acta Pharm. Sinica, 1997, 32, 110–115) was obtained from the cytotoxic fraction of 95% ethanol extracts of stem barks of Albizia julibrissin Durazz, together with Julibroside J2. Its structure was elucidated as 3-O-[β-D-xylopyranosyl-(1 → 2)-α-L-arabinopyranosyl-(1 → 6)-β-D-glucopyranosyl]-21-O-{(6S)-2-trans-2-hydroxymethyl-6-methyl-6-O-[3-O-((6S)-2-trans-2-hydroxymethyl-6-methyl-6-hydroxy-2,7 -octadienoyl)-β-D-quinovopyranosyl]-2,7-octadienoyl} acacic acid 28-O-β-D-glucopyranosyl-(1 → 3)-[α-L-arabinofuranosyl-(1 → 4)]-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl ester(1), named as Julibroside J7, based on chemical and spectral methods. Julibroside J2 showed good inhibitory action against KB cell line in vitro.