Biologically active flavonoids and terpenoids from Egletes viscosa.

The steam volatile components from the hexane extract of dried flower buds of Egletes viscosa were identified by gas chromatography-mass spectrometry as trans-carvyl acetate, cis-carvyl acetate, sabinyl acetate, verbenyl acetate, cyclopentaethylidene, geranyl acetate and 5-methylfuranone, and trans-pinocarvyl acetate (major component). From the non-volatile residue, centipedic acid and a novel clerodane diterpene, 12-acetoxy-hawtriwaic acid lactone, were isolated. From the ethanol extract, ternatin (4',5-dihidroxy-3,3',7,8-tetramethoxyflavone), was isolated. Ternatin showed anti-inflammatory, hepatoprotection and gastroprotection properties, and, according to the NCI protocols, it showed moderate activity against HIV. The diterpenes showed antispasmodic activity. Structure determination of these secondary metabolites was accomplished by spectrometric methods, including 2D NMR, chemical interconversion and X-ray crystallographic analysis.