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

Abstract

Recebido em 13/12/10; aceito em 21/3/11; publicado na web em 5/5/11From 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.

The Essential Oil from <b><i>Origanum vulgare</i></b> L. and Its Individual Constituents Carvacrol and Thymol Enhance the Effect of Tetracycline against <b><i>Staphylococcus aureus</i></b>

“…Most of the available studies that assessed this property in plant products involve extracts and/or their individual or group constituents. Phenolic compounds (acacetin and 7,4-di-O-methylisoscutellarein) of Sidastrum micranthum (A. Sr.-Hill) Fryxell, Malvaceae family, modulated the TetK efflux pump and MsrA macrolide efflux protein in S. aureus [16]. Flavones of Praxelis clematidea R.M.…”

Tannic Acid as a Potential Modulator of Norfloxacin Resistance in <b><i>Staphylococcus Aureus</i></b> Overexpressing <b><i>norA</i></b>

“…As only TA possessed Nor-resistance modulatory activity [15], further investigations into whether these effects were related to the NorA efflux pump inhibition using the ‘modulatory assay' were carried out. The assay is able to identify potential modulatory antibiotic resistance effects and is an indicator of efflux pump inhibition when specific efflux-positive strains are used [14].…”

“…To determine whether any Nor resistance modulation occurred by inhibiting the NorA efflux pump, the MIC of EtBr alone or in combination with TA or GA was assessed. EtBr was included in this assay as an indicator of NorA efflux pump inhibition [15]. EtBr is a well-known substrate for efflux proteins, and active efflux is the only known mechanism of resistance to this DNA-intercalating dye [16].…”

Estudos Interdisciplinares em Ciências Exatas e da Terra

“…No Brasil, ocorrem cerca de 80 gêneros e 400 espécies (CARVALHO;GAIAD, 2015). Produtos naturais extraídos de plantas que pertencem à família Malvaceae são utilizados no tratamento de muitas enfermidades, entre elas picadas de cobra, asma, distúrbios gastrointestinais e reumatismo, como diurético, entre outros (GOMES et al, 2011). Estudo químico realizado com espécies pertencentes a essa família descreve o isolamento de ácidos graxos, óleos essenciais, sesquiterpenoides do tipo cadineno, lactonas sesquiterpê-nicas, triterpenoides, flavonoides, entre outros compostos (COSTA et al, 2009 A espécie Eriotheca pubescens (Mart.…”