Biologically active alkamide from the lichen Stereocaulon alpinum

The presence of an alkamide in lichens is reported for the first time. The alkamide was isolated from Stereocaulon alpinumLaur. and identified through spectroscopic analysis as 9-cis-octa-decenamide (1). With reference to previously known activity of alkamides from both the plant and animal kingdoms on inflammatory processes, 1 was tested for in vitroinhibitory 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 from sheep seminal vesicle microsomes (IC50= 64.3 μM) whilst showing only slight activity against 5-lipoxygenase from porcine leucocytes.