A New Isoflavan From the Heartwood of Dalbergia cochinchinensis

Abstract

A new isoflavan, named dalbergiacochan A (1), was isolated from the heartwood of Dalbergia cochinchinensis, along with two known isoflavans, namely mucronulatol (2) and 2′-O-methylsepiol (3). Their structures were elucidated based on extensive spectroscopic analyses, including one-dimensional (1D) and two-dimensional nuclear magnetic resonance (2D NMR), and mass spectroscopy (MS) data, and the absolute stereochemistry of compound 1 was determined as R-3′,6-dihydroxy-2′,4′,8-trimethoxyisoflavan from its circular dichroism spectrum. Compound 1 was inactive against Escherichia coli, Bacillus thuringiensis, and Shigella dysenteriae.