Synthesis and antimycobacterial activity of (+) ‐usnic acid conjugates

Seventeen conjugates of (+) ‐usnic acid with selected polar amino acids or amines or with aromatic and heterocyclic hydrazines and hydrazides are described and tested against sensitive and multidrug‐resistant (MDR) mycobacteria strains. DerivativesPS14 andPS18 showed potent activity against MDRMycobacterium tuberculosis strains, with MIC values comparable to those of other antitubercular drugs already in use for tuberculosis treatment. AbstractNew therapeutics are urgently needed to fight tuberculosis and mycobacteria ‐related diseases that are a major health hazard especially in poor countries. Natural products have been the source of important antitubercular drugs in the past and still need to receive attention as a potent reservoir of chemical structures. Fifteen known and two new (+)‐usnic acid (a benzofu randione formerly isolated from lichens) enamines and hydrazones are here described and tested against sensitive and multidrug‐resistant strains of mycobacteria. Among several (+)‐usnic acid conjugates,PS14 andPS18 showed potent activity against both susceptible and resistantMycobacterium tuberculosis strains (MIC values of 1 –32 and 2–32 mg/L, respectively) comparable with MIC of other antitubercular drugs already in use for tuberculosis treatment.
Source: Archiv der Pharmazie - Category: Drugs & Pharmacology Authors: Tags: FULL PAPER Source Type: research