Bioactive flavanoids from Glycosmis arborea

Glycosmis is a genus of evergreen glabrous shrub and distributed all over India. It possesses various medicinal properties and is used in indigenous medicine for cough, rheumatism, anemia, and jaundice. Glycosmis arborea is a rich source of alkaloids, terpenoids, coumarins, as well as flavonoids.

The chemical investigation of methanol fraction of the leaves of G. arborea led to the isolation of one new flavone C-glycoside along with three known flavanoids, named as 5,7-dihydroxy-2-[4-hydroxy-3-(methoxy methyl) phenyl]-6-C-β-d-glucopyranosyl flavone (4), 5,7,4'-trihydroxy-3'-methoxy flavone (1), 5,4'-dihydroxy-3'-methoxy-7-O-β-d-glucupyranosyl flavanone (2), and 5,4'-dihydroxy-3'-methoxy-7-O-(α-l-rhamnosyl-(1‴→6‴)-β-d-glucopyranosyl) flavanone (3), respectively. The structures of all compounds were elucidated with the help of nuclear magnetic resonance spectrometry. Pure compounds and fractions were evaluated for pest antifeedant and antimicrobial activity.

Four compounds were isolated from the leaves of G. arborea. Among them, compound 4 showed significant antimicrobial activity.