Antituberculosis activity of alkylated mulinane diterpenoids

Natural azorellane and mulinane diterpenoids show antituberculosis activity, which is increased by methylation of their free carboxyl group. We have systematically investigated the effect of alkylation in this class of diterpenoids and found that the profile of bioactivity is relatively unaffected by the introduction of short alkyl groups, both linear and branched. In this investigation, three semisynthetic diterpenoids, 13 hydroxy-mulin-11-en-20-oic acid n-propyl ester (3) and the n-propyl (19) and n-butyl (20) esters of isomulinic acid, showed the strongest antituberculosis activity (MIC = 6.25 μg/mL) against a drug-resistant strain of Mycobacterium tuberculosis.

Eighteen linear and branched alkylated mulinane diterpenoids were assayed for antituberculosis activity. The esters (3), (19) and (20) displayed the strongest activity against a drug-resistant strain of Mycobacterium tuberculosis.Figure optionsDownload as PowerPoint slide