Antimicrobial activity of isolated compounds and semisynthetic derivatives from Miconia ferruginata

Abstract

This study evaluated the antimicrobial activity of isolated compounds and semisynthetic derivatives from Miconia ferruginata (Melastomataceae) against five microorganisms: Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922), Bacillus subtilis (ATCC 6623), Pseudomonas aeruginosa (ATCC 15442), and Candida albicans (ATCC 10231). The isomeric mixture of ursolic and oleanolic acids was active against S. aureus (MIC = 250 μg mL-1) and against E. coli, B. subtilis, and P. aeruginosa (MIC = 500 μg mL-1). The flavone 5,6,7-trihydroxy-4’-methoxyflavone and the methyl esters, semisynthetic derivatives of a mixture of ursolic and oleanolic acids, showed no activity against the tested microorganisms. These results suggest that the carboxyl group present in the triterpenes may contribute to antimicrobial activity.

Flavanone Glycosides, Triterpenes, Volatile Compounds and Antimicrobial Activity of Miconia minutiflora (Bonpl.) DC. (Melastomataceae)

“…Some compounds obtained from Miconia species also demonstrated antimicrobial activity such as the mixture of ursolic and oleanolic acids isolated from M. ferruginata leaves that was active against S. aureus , E. coli , Bacillus subtilis , and Pseudomonas aeruginosa [ 31 ]. The antifungal activity of the isolated compound pinocembroside (S4) was previously described using in vitro mycelial growth of Penicillium italicum, showing an MIC and minimum fungicidal concentration (MFC) of 200 and 800 mg·L −1 , respectively, [ 32 ] and against Penicillium digitatum, with a half-maximal effective concentration (EC 50 ), MIC, and MFC of 120.3, 200, and 400 mg·L −1 , respectively [ 33 ].…”