A New Flavanone as a Potent Antioxidant Isolated from Chromolaena odorata L. Leaves.

Chromolaena odorata L. (Asteraceae) is one of the tropical plants which is widely used as traditional medicines for diabetes and soft tissue wounds treatment in some regions in East Indonesia. The present study was aimed at determining the bioactive compounds of C. odorata leaves. The methanol and ethyl acetate extracts of C. odorata leaves have the inhibitory activity against 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals as well as α-glucosidase rat intestine enzyme. A new flavanone was isolated from the methanol extract and elucidated as 5,3'-dihydroxy-7,6'-dimethoxyflavanone or, namely, odoratenin (1) together with two known compounds: isosakuranetin (2) and subscandenin (3). The antioxidant activity of odoratenin (1) exhibited very potent ABTS radical inhibitory activity with IC₅₀ value of 23.74 μM which is lower than that of trolox (IC₅₀ 31.32 μM) as a positive control. The result showed that a new flavanone, odoratenin (1), should be potential as an antioxidant source.