Antimycobacterial polyacetylenes from Levisticum officinale

No conflicts of interest concerning financial matters or personal relationships exist between the authors and those who might bias this work. The present work is in part included the PhD thesis of A. Schinkovitz (University of Graz) but has not been published elsewhere previously. The dichloromethane extract of the roots of Levisticum officinale L. (Apiaceae) exhibited significant anti-mycobacterial activity against Mycobacterium fortuitum and Mycobacterium aurum in a microtiter plate dilution assay and was further analysed following a bioassay-guided fractionation strategy. 3(R)-Falcarinol (3(-)-)-1,9-heptadecadien-4,6-diin-3-ol] and 3(R)-8(S)-falcarindiol [3(R)-8(S)-(+)-1,9-heptadecadien-4,6-diin-3,8-diol] could be identified as the active components in this extract. The minimal inhibitory concentration (MIC) of 3(R)-falcarinol against M. fortuitum and M. aurum was 16.4 mu M while that of 3(R)-8(S)-falcarindiol was 30.7 mu m against M. fortuitum and 61.4 mu m against M. aurum, respectively. Previously, 3(R),8(R)-dehydrofalcarindiol was isolated from Artemisia monosperma and surprisingly this polyacetylene exhibited no antimycobacterial activity at 128 mu g/mL. This indicates that the terminal methyl group is vital for retention of antimycobacterial activity. Reference antibiotics ethambutol and isoniazid exhibited an activity of 115.5 mu M and 14.6 mu m against M. fortuitum, and 3.4 mu m and 29.2 mu m against M. aurum, respectively. Copyright (C) 2008 John Wiley & Sons, Ltd.