The presence of an alkamide in lichens is reported for the first time.
The alkamide was isolated from Stereocaulon alpinum Laur. and identif
ied through spectroscopic analysis as 9-cis-octadecenamide (1). With r
eference to previously known activity of alkamides from both the plant
and animal kingdoms on inflammatory processes, 1 was tested for in vi
tro inhibitory activity against the key enzymes of the major pathways
involved in arachidonate metabolism. The compound was shown to exhibit
moderate dose-dependent inhibitory activity against cyclooxygenase fr
om sheep seminal vesicle microsomes (IC50 = 64.3 mu M) whilst showing
only slight activity against 5-lipoxygenase from porcine leucocytes.