One new lignan, nirtetralin B, along with its two known stereoisomers were isolated from Phyllanthus niruri L. The structure of the new compound was determined by spectroscopy experiments and x-ray diffraction analysis. These lignans were assayed for anti-hepatitis B virus activities in vitro.
Phyllanthus niruri L. (P. niruri) distributes in tropical and subtropical regions. It has been thoroughly investigated for its significant activities of anti-hepatitis B virus. Previous studies on this plant have led to the discovery of 21 lignans, which are mainly phenyltetralin and dibenzylbutane types, among them niranthin and nirtetralin suppressed effectively both HBsAg and HBeAg expression in vitro.
Plant material. Herb material of Phyllantthus niruri L. was collected in Longan, Guangxi province, China, in November 2007, and identified by Dr Shifeng Ni, Northwest University, Xi an, China. A voucher specimen (2007-p-1) was deposited in the Department of Chemistry, Guangxi University for future reference.