Nitric Oxide (NO) Production Inhibitory Constituents of Tabebuia avellanedae from Brazil

Abstract

From the water extract of Brazilian Tabebuia avellanedae, two new iridoids (1, 2) and a new phenylethanoid glycoside (3) have been isolated together with twelve known compounds (4—15). Their structures were determined based on the spectroscopic data. The isolated compounds inhibited nitric oxide (NO) production in lipopolysaccharide (LPS)-activated macrophage-like J774.1 cells. Compounds 1, 3, 10, 11, and 12 showed inhibitory activities more potent (IC₅₀, 13.8—26.1 μg/ml) than a positive control N^G-monomethyl-L-arginine (L-NMMA; IC₅₀, 27.4 μg/ml).