Antitubercular Activity Increase in Labdane Diterpenes from Copaifera Oleoresin through Structural Modification
作者:Aline Silva、Ana Carolina Soares、Mirela Cabral、Alex de Andrade、Marilza da Silva、Carlos Martins、Rodrigo Veneziani、Sérgio Ambrósio、Jairo Bastos、Vladimir Heleno
DOI:10.21577/0103-5053.20160268
日期:——
The labdane diterpenes copalic acid, 3 beta-acetoxy-copalic acid, 3 beta-hydroxy-copalic acid and ent-agathic acid were isolated from Copaifera langsdorffii oleoresin. These four compounds were submitted to structural modifications by reduction with hydrogen/palladium, esterification with diazomethane, esterification with methanol/sulfuric acid and conversion into sodium salt, furnishing 15 compounds. All compounds were assayed in vitro against Mycobacterium tuberculosis (H37Rv, ATCC 27294). The four compounds displayed minimum inhibitory concentration (MIC) value of 125 mu g mL(-1), and were not considered active. A methylated derivative of compound 3 beta-hydroxy-copalic acid, and a sodium salt of copalic acid displayed MIC values of 25 mu g mL(-1) (71.7 mu M) and 6.25 mu g mL(-1) (19.2 mu M), respectively. The sodium salt of copalic acid stood out by displaying similar activity in comparison with streptomycin (MIC 6.25 mu g mL(-1)) and a better activity compared to mu M value of pyrazinamide (MIC 3.12 mu g mL(-1); 25.34 mu M). Therefore, the methylated derivative of compound 3 beta-hydroxy-copalic acid and the sodium salt of copalic acid should be considered for further studies.