Cytotoxic Glycosides from Albizia julibrissin

Abstract

During the course of a study of leguminous plants, cytotoxicity was demonstrated by the crude saponin fraction of Albizia julibrissin. Following chromatographic purification, the structures of three novel saponins, julibrosides I-III (1-3), inclusive of a cytotoxic principle, were elucidated. A comparison of the cytotoxicity of julibrosides (1-3) and their prosapogenins (4-15) prepared by alkaline hydrolysis clearly indicated that both an alpha-L-arabinofuranosyl-(1-->4)-[beta-D-glucopyranosyl-(1-->3)]-alpha- L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl ester unit and a monoterpene-quinovopyranosyl moiety are crucial substituents for cytotoxicity among this class of compounds. The hydroxy group at C-16 of aglycon may play an important role in mediating cytotoxicity, and the N-acetyl-glucosamine moiety at C-3 seems to enhance activity because 3 showed the strongest cytotoxicity.

A review of acacic acid-type saponins from Leguminosae-Mimosoideae as potent cytotoxic and apoptosis inducing agents

“…In Korea, the stem bark is used in traditional medicine to treat insomnia, diuresis, asthenia, ascaricide, and confusion. Ikeda et al (1997) demonstrated that the crude saponin fraction obtained from A. julibrissin showed significant (IC 50 12.8 lg/ml) cytotoxicity against the KB cell line. Following chromatographic purification, julibrosides I-III (20-22) were obtained (Fig.…”

“…The cytotoxicity profile of Julibrosides I-III (20-22) was examined against the KB cell lines (Ikeda et al 1997). Only julibroside III (22) showed significant cytotoxicity with an IC 50 value of 0.9 lM.…”

“…The following discussion will focus on the relationships between their structure features and antitumor activities. It was reported that the monoterpene-quinovopyranosyl moiety at C-21 and the oligosaccharide ester at C-28 of the acacic acid-type aglycon are crucial substituents required for the cytotoxicity of Julibroside III (22) and its prosapogenins against KB cells and their hydroxyl group at C-16 may also be important for the cytotoxicity (Ikeda et al 1997). It was also reported that the trisaccharide unit at C-3 of kinmoonosides A-C (1-3) was not crucial for their cytotoxicity, but oligosaccharides at position-3 of the aglycone may intensify the cytotoxicity of acacic acid derivatives (Tezuka et al 2000).…”

Phenolic Glycosides from the Stem Bark of Albizzia julibrissin

“…1) Earlier phytochemical investigations on this species resulted in the isolation of saponins, [2][3][4][5] lignans, [6][7][8] phenolic glycosides, 6) triterpenes, 9) flavonoids and others. [10][11][12][13][14][15] Previously, we reported that the methanolic extract of the stem bark of A. julibrissin exerts an radical scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical.…”

An efficient synthesis of julibrosides related to neosaponin

“…3 This finding prompted us to prepare neosaponins carrying the original tetrasaccharide component and to examine their biological activities.…”