Printed in Great Britain. <o 1994 lUPAC Cytotoxic lignans from Haplophyllum species

Abstract: Four new lignans were isolated from Haplophyllum ptilosyhm, their structures were establihed by spectral data, using COSY, HETCOR, COLOC, selective INEPT experiments. Pharmacological tests were performed on human cell lines and HIV-1 reverse transcriptase. The success of semisynthetic anticancer drugs etoposide (1) and teniposide (2) focused the attention on the availability of podophyllotoxin (3) which was first isolated from PodophyZlum peltaturn L. later in higher quantity from P.hexundium [l]. Since the total synthesis of podophyllotoxin is uneconomic, either systematic cultivation of the plant or tissue culture methods could be used to produce compound 3, a third way is to screen seed bearing plants for aryltetraline lignans [2]. During the OH OM&amp