Isolation and Characterization of Compounds from the Methanolic Bark Extract of Adenanthera pavonina L.

Abstract

A known flavonoids 7-methoxycatechin (1) along with two oleanane type triterpenoid saponins 3-[(2'-acetamido-2'-deoxy-β-D-glucopyranosyl)oxy]-olean-12-en-28-oic acid (2), 3-[(2'-acetamido-2'-deoxy-β-D-glucopyranosyl)oxy]-16-α-hydroxyolean-12-en-28-oic acid (3) and a new flavonoid 3-O-β-D-glucopyranosyl-7-O-methyl catechin (4) were isolated from the crude methanolic extract by extensive chromatographic separation. Moreover, a known 3-O-β-D-glucopyranosyl-21- methylcarboxy-olean-12-en-28-oic-acid (5) and a new 3-O-β-D-glucopyranosyl-21-methyl carboxyolean-18-en-28-oic acid (6) oleanane type triterpenoid saponins were further isolated from the butanol fraction along with a known benzoic acid derivative 2-hydroxy-1,2-diphenyl ethanone (benzoin) (7) was separated from ethyl acetate fraction of methanolic bark extract of Adenanthera pavonina L. The structures of the known and new compounds were elucidated by spectroscopic techniques.

GRAPHICAL ABSTRACT

Key words:

• Adenanthera pavonina
• bark
• catechin
• methanolic extract
• triterpenoid saponin