The isomeranzin, a coumarin was isolated from the leaves of Clausena heptaphylla. The structure was elucidated by IR, MS, 1H and 13C-NMR. For the first time, the anti-Herpes simplex virus type 1 & 2 in vitro activity of the compound was reported and discussed. I - introduction Clausena heptaphylla (Roxb.) W. & Arn. (Rutaceae) (Vietnamese name: Giæi 7 l) is a tropical tree [1]. This species is also widely used in traditional medicine. In Asia (China, India, Vietnam, etc.), it is used for fever. Several groups have reported the isolation of the isomeranzin from Skimmia japonica [2], Triphasia trifloliata [3],.
