A New Chalcone and a Flavone from Andrographis neesiana

Abstract

Two new flavonoids, 2′,4′,6′,2,3,4-hexamethoxychalcone (1) and 5-hydroxy-7,2′,5′-trimethoxyflavone (2) together with a known flavone glycoside, echioidinin 5-O-β-D-glucopyranoside (3) were isolated from the whole plant of Andrographis neesiana, and the structures were elucidated by electrospray ionization tandem mass spectrometry (ESI-MS/MS) and one- and two-dimensional (1D- and 2D)-NMR spectral studies including ¹H–¹H correlation spectroscopy (COSY), heteronuclear single quantum coherence (HSQC), heteronuclear multiple bond connectivity (HMBC) and nuclear Overhauser enhancement spectroscopy (NOESY) experiments.