Natural anti-HIV agents—part I: (+)-demethoxyepiexcelsin and verticillatol from Litsea verticillata
摘要:
The eudesmane sesquiterpenoid, verticillatol (1), as well as the lignan, (+)-5'-demethoxyepiexcelsin (2), and a known lignan, epiexcelsin (3), were isolated from Litsea verticillata Hance. Lignan 2 showed moderate anti-HIV activity with an IC50 value of 16.4 mug/ml (42.7 muM), while the known lignan 3 was inactive up to a concentration of 20 mug/ml (48.3 muM). Compound I demonstrated weak activity with an IC50 value of 34.5 mug/ml (144.7 muM) while being devoid of cytotoxicity at 20 mug/ml. The structures were elucidated by 1D and 2D NMR spectroscopy, and the absolute configuration of the new sesquiterpenoid was determined by the generation of Mosher esters. (C) 2002 Elsevier Science Ltd. All rights reserved.