ABSTRACT
ABSTRACTThe antimicrobial activity of the myrsinoic acid A isolated from Myrsine coriacea (Sw.) R.Br. ex Roem. & Schult., Primulaceae, and a two semi-synthetics derivatives was tested against Bacillus subtilis, Escherichia coli, Salmonella enterica subsp. enterica serovar typhi, Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa, Micrococcus luteus, Candida albicans, Candida krusei and Candida tropicalis. The microdilution method was used for the determination of the minimum inhibitory concentration during evaluation of the antimicrobial activity. The myrsinoic acid A showed no activity against the selected microorganisms but the hydrogenated and acetylated derivatives were active against B. subtilis, E. coli, S. aureus and P. aeruginosa.
ABSTRACT
Byrsonima coccolobifolia leaf and stem extracts were studied in the search for possible leishmanicidal compounds using arginase (ARG) from Leishmania amazonensis as a molecular target. Flavonoids 1b, 1e-1g, 2a, 2b, and 2d-2f showed significant inhibitory activity, with IC50 values ranging from 0.9 to 4.8 µM. The kinetics of the most active compounds were determined. Flavonoids 1e, 1f, 2a, 2b, and 2e were characterized as noncompetitive inhibitors of ARG with dissociation constants (Ki) ranging from 0.24 to 3.8 µM, demonstrating strong affinity. Structure-activity relationship studies revealed some similarities in the structural features of flavonoids related to ARG activity.
