Chemical composition, antimicrobial and antimycobacterial activities of Aristolochia triangularis Cham. from Brazil

摘要

Three diterpenes (1, 4, 5), four lignans (2, 6, 7a, 7b), one sequiterpene (3) and one alkaloid (8) were isolated from an acidic ether fraction of Aristolochia triangularis Cham. native from Brazil. The compounds were identified as: ent-Kaur-16-en-19-al (1), zuonin B (2), nerolidol (3), (-)-Kaur-16-en-19-oic acid (4), ent-Kauran-16 beta,17-diol (5), dihydrocubebin (6), a mixture of alpha and beta-cubebin (7a + 7b) and aristolactam BII (8). The methanol extract, fractions and the isolated substances were evaluated to check their antimicrobial/antimycobacterial activity against bacteria (14 strains), fungi (9 strains) and mycobacteria (3 strains). Shigella sonnei was highly susceptible to ( -)-Kaur-16-en-19-oic acid (4), which showed a potency similar to the antibacterial substance chloramphenicol (MICs at & 1.5 mu g/mL). This diterpene also exhibited excellent bacteriostatic and bactericidal (MIC/MLC = 3.1/6.2 mu g/mL) activity against Enterobacter aerogenes, being considered a better bactericidal substance than the controls ampicillin and chloramphenicol, and it also presented high bioactivity against Salmonella enterica serovar Typhimurium, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus (MIC values of 3.1 mu g/mL) and Shigella floated (MIC = 6.2 mu g/mL). ent-Kaur-16-en-19-al (1) showed good activity against Shigella flexneri, Staphylococcus aureus, Salmonella enterica serovar Typhimurium and Enterobacter aerogenes (MICs between 6.2 and 12.5 mu g/mL). Compounds 4 and 8 inhibited the Candida lcrusei growth, with MICs = 6.2 mu g/mL. All extract, fractions and the isolates tested showed a promising degree of antimycobacterial activity mainly against Mycobacterium abscessus. Nerolidol (3) presented the highest antimycobacterial activity (MICs of 4.9-19.9 mu g/mL).