ALECTOSARMENTIN, A NEW ANTIMICROBIAL DIBENZOFURANOID LACTOL FROM THE LICHEN, ALECTORIA-SARMENTOSA

From the alcoholic extract of the lichen Alectoria sarmentosa, four co mpounds showing antimicrobial activity were isolated. Of these, (-)-us nic acid and physodic acid are well known lichen produces, 8'-O-ethyl- beta-alectoronic acid [2] is believed to be an artifact Formed during isolation and fractionation, and alectosarmentin [1] is a new natural product whose structure was shown, by spectroscopy and chemical transf ormations, to be that of a dibenzofuranoid lactol. The antimicrobial a ctivity of these substances accounts for the activity of the lichen.