New C-methylated flavonoids and α-pyrone derivative from roots of Talinum triangulare growing in Nigeria

Abstract

The first chemical examination of roots of the traditionally used medicinal plant Talinum triangulare (Portulacaceae) from Nigeria led to the isolation of two new C-methylated flavonoids, 5,6-dimethoxy-7-hydroxy-8-methyl-flavone (1), 5,6-dimethoxy-8-methyl-2-phenyl-7H-1-benzopyran-7-one (2), and one new α-pyrone derivative, 4-methoxy-6-(2-hydroxy-4-phenylbutyl)-2H-pyran-2-one (3), along with thirteen known compounds, including nine amides (4-12), indole-3-carboxylic acid (13), p-hydroxy benzoic acid (14), and two steroids (15-16). Their structures were elucidated by extensive spectroscopic measurements including 1D, 2D NMR, MS, and by comparison with the literature. All isolated compounds were screened for their cytotoxic and antifungal activities. However, none of them showed significant activity.

Keywords: Amides; C-methylated flavonoids; Talinum triangulare; α-pyrone.