Benzene, coumarin and quinolinone derivatives from roots of Citrus hystrix.

Two coumarins, hystrixarin (1) and (+)-hopeyhopin (2); a benzenoid derivative, hystroxene-I (3) and a quinolinone alkaloid, hystrolinone (4), along with 33 known compounds were isolated from the crude acetone extract of the roots of Citrus hystrix. Their structures were determined by analysis of 1D and 2D NMR spectroscopic data. The antioxidant, anti-HIV and antibacterial activities of the isolated compounds were also evaluated.