Monoamine oxidase inhibitory effects of some lichen compounds and their synthetic analogues

Four 5-acylresorcinol (1-4), twenty 5-alkylresorcinol (5-24), six 4-acylresorcinol (25-30) and three 4-alkylresorcinol (31-33) derivatives were synthesized and examined for mice liver monoamine oxidase (MAO) inhibitory effects. Among these compouds, some one (compounds 6-9, 11-13, 16 and 21-24) were known as lichen metabolites. Some compounds showed mice liver MAO inhibitory effects which corresponded to the length of the side chain; 4-acylresorcinol which has R=C6H13 as the side chain showed potent activity IC50, 4.27X10(-6) M). The compounds showing mice liver MAO inhibitory effects were tested for mice brain MAO inhibitory potencies.