Pterocarpans and derrisisoflavones have been associated with a broad range of biological activities, including insecticidal, antimicrobial, cytotoxic, and antioxidant activities. These phytochemicals have been isolated from the genus Derris belonging to the Leguminosae family [1]. In the present study, some pterocarpans and derrisisoflavones were isolated from the root bark of Millettia aboensis using a combination of different chromatographic techniques including VLC, Sephadex LH-20 separation and semi-preparative HPLC. The structures of the compounds were elucidated by a combination of MS and NMR spectroscopy. The crude methanol root extract was screened for its cytotoxic activity on mouse lymphoma cell line (L5178Y) and the isolated compounds were tested for their antioxidant activity using 2, 2-diphenylhydrazyl (DPPH) radical scavenging model. The crude methanol root extract exhibited a growth inhibition of 87.5% on mouse lymphoma cell line (L5178Y) . The ethyl acetate fraction of the methanol root extract of M. aboensis yielded three new compounds; one pterocarpan, 9-hydro-3,8-dimethoxyl pterocarpan (1); two derrisisoflavones, derrisisoflavone L (3) and derrisisoflavone M (4), which were identified on the basis of spectroscopic techniques. Two known compounds maackiain (2) and derrisisoflavone G (5) were also isolated. The isolated compounds showed promising antioxidant activity with compound 2 having the highest activity with an IC50 of 83 µg/ml. This is the first report on the isolation of pterocarpans and derrisoflavones from the root of M. aboensis . These compounds hold great potential for development into novel therapeutic molecules
Reference
Guo-Zhu W , Mei-Fen M , Xiang-Mei L , Fu-Cai R , Fei W . Nat Prod Bioprospect 2016; 6(2): 111–116.