Antibacterial and Inhibitory Activities against Nitric Oxide Production of Coumaronochromones and Prenylated Isoflavones from Millettia extensa

Authors

Achara Raksat, Mae Fah Luang University
Wisanu Maneerat, Mae Fah Luang University
Narawadee Rujanapun, Mae Fah Luang University
Raymond J. Andersen, University of British Columbia
Stephen G. Pyne, University of WollongongFollow
Surat Laphookhieo, Mae Fah Luang UniversityFollow

RIS ID

138706

Publication Details

Raksat, A., Maneerat, W., Rujanapun, N., Andersen, R. J., Pyne, S. G. & Laphookhieo, S. (2019). Antibacterial and Inhibitory Activities against Nitric Oxide Production of Coumaronochromones and Prenylated Isoflavones from Millettia extensa. Journal of Natural Products, 82 2343-2348.

Abstract

A chemical investigation of leaf and root extracts of Millettia extensa led to the isolation and structural elucidation of four new prenylated isoflavones, millexatins G-J (1-4), and three new coumaronochromones, millexatins K-M (5-7), along with 16 known compounds. The structures of the new compounds were determined on the basis of NMR and MS data. Compound 4 is a rare isoflavone having a 2-hydroxyethyl moiety at C-8, whereas the structures of compounds 5-7 formally arise from a ring closure through HO-2′ and C-2. The absolute configurations at the C-2 and C-3 positions of 5 and 6 were determined from their ECD spectra through comparison with those of previously reported compounds. Most of compounds were evaluated for their inhibitory effects against nitric oxide (NO) production on RAW264.7 macrophages and their antibacterial activities. Compounds 18 and 19 inhibited NO production with IC50 values of 8.5 and 14.3 μM, respectively. Compounds 13 and 14 showed antibacterial activity against various Gram-positive bacteria with MIC values ranging from 2 to 8 μg/mL.