Phenolic compounds from Sidastrum micranthum (A. St.-Hil.) fryxell and evaluation of acacetin and 7,4'-Di-O-methylisoscutellarein as motulator of bacterial drug resistence

• Main Authors: Roosevelt A. Gomes, Rafael R. A. Ramirez, Jéssica Karina da S. Maciel, Maria de Fátima Agra, Maria de Fátima Vanderlei de Souza, Vivyanne S. Falcão-Silva, José P. Siqueira-Junior
• Format: Article
• Language: English
• Published: Sociedade Brasileira de Química 2011-01-01
• Series: Química Nova
• Subjects: Sidastrum micranthum; Malvaceae; modulation of drug resistance
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422011000800016&lng=en&tlng=en

From the aerial parts of Sidastrum micranthum (A. St.-Hil.) Fryxell (Malvaceae) were isolated m-methoxy-p-hydroxy-benzaldehyde, o-hydroxy-benzoic acid, acacetin, quercetin, 7,4′-Di-O-methylisoscutellarein, genkwanin and tiliroside. These compounds were identified by data analyses of spectroscopic methods. Although acacetin and 7,4′-Di-O-methylisoscutellarein did not display relevant antibacterial activity (MIC = 256 µg/mL), they modulated the activity of antibiotics, i.e. in combination with antibiotics at 64 µg/mL (¼ MIC), a two-fold reduction in the MIC was observed for norfloxacin and ethidium bromide; regarding tetracycline and erythromycin a two-fold reduction in the MIC was observed only with 7,4′-Di-O-methylisoscutellarein.