STRUCTURE-ANTIMICROBIAL ACTIVITY RELATIONSHIPS OF ABIETANE DITERPENESFROM SALVIA SPECIES

Twenty-one abietatriene diterpenes isolated from Salvia species were e valuated for antimicrobial activity against three strains of bacteria and one yeast. The results obtained show that the free catechol groupi ng is essential for antimicrobial activity against Gram-positive bacte ria and that activity appears to be independent of the closing positio n of the lactone group in the class A compounds. If there was an extra hydroxyl group at C-6 or C-7, activity was reduced to less than a thi rd, and a hydroxy-methylene group at C-16 also rendered the products i neffective. Compounds where the catechol grouping had been oxidized to a quinone exhibited enhanced activity.