Phytochemical investigation of the leaf extracts from Miconia ferruginata (Melastomataceae) led to the isolation and characterization of the flavonoids 5,6,7-trihydroxy-4'-methoxyflavone, 5-hydroxy-7,4'-dimethoxy-8-methylflavone and 5,7,4'-trihydroxy-6,8-dimetilflavone, triterpenes ursolic acid and oleanolic acid, in addition to the steroids β-sitosterol and stigmasterol. The structures of these compounds were proposed by spectroscopic analysis and comparison with literature data. This paper also describes the insecticidal effects of leaf extracts from M. ferruginata to one of the main pests of maize, the fall armyworm (Spodoptera frugiperda). The ingestion bioassays, the leaf extracts showed an elongation of the larval stage of 16.56 days as compared to the control.

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.