Abstract
This study aimed to present the activity guided fractionation, isolation and characterization of antioxidants and antibacterial agents from combined mixture of plants (Vitex doniana, Diospyros mesipiliformis, Acacia polycantha, Pirinari macrophylla, Ficus sycomorus and Parkia biglobosa) and that of Pergularia tomentosa. Combined Mixture of Plants (CMP) is used locally in ratio of 1:1 for the treatment of bacterial infections. The CMP and P. tomentosa were extracted with methanol separately; the residues obtained were also separately suspended in water and successively fractionated with hexane, ethylacetate and n-Butanol. All the fractions obtained were screened for antimicrobial and antioxidant activities. For CMP, only the ethyl acetate fraction (EF) indicated marginal antibacterial activity with 8.0, 7.0 and 7.0 mm zone of inhibition against Micrococcus luteus (MTCC 2470), Bacillus subtilis (MTCC 121) and Salmonella typhimurium respectively. Minimum inhibitory concentration (MIC) for the CMP was greater than 1000 for M. luteus and S. typhimurium and 87.5 μg/ml for B. subtilis. The CMP fraction was subjected to chromatographic separations which resulted in the isolation and characterization of five bioactive constituents, gallic acid, 3β-OH-α-amyrin, 5,7,3’.4’,5’-pentahydroxy-3-O-glucophyranoside flavones (myricetin 3-O-β-rhamnopyranoside), 5,7,3’,4’ tetrahydroxy-3-O-glucopyranoside flavone (quercetin 3-O-β-rhamnopyranoside) and 3,5,7,3’,4’-pentahydroxy flavones (quercetin). They were characterized with the help of ESI-MS, IR, 1H C13, HMBC/HSQC and COSY-NMR data. These compounds did not show antibacterial activity when tested separately but exhibited appreciable antioxidant activities in different manner. Chromatographic fractionation of hexane extract of P. tomentosa resulted in the isolation of lupeol acetate (LA) with marginal but selective activity against M. luteus and the activity is due to LA rather than the combined constituents. These findings suggest that the fractions of the extracts and pure compounds possess antibacterial and antioxidant properties. Key words: Antioxidant properties, antibacterial activity, NMR data, Pergularia tomentosa, combined mixture of plants.
Highlights
Diseases caused by pathogenic bacteria and fungi present critical problem to human health and are one of the main causes of morbidity and mortality worldwide (WHO, 1998)
Combination therapy is an alternative approach in the search for novel compounds with ability to deal with antibiotic resistant microorganisms
Lupeol acetate belongs to lupane type triterpenes and was reported to have antimicrobial activity (Prachayasittikul et al, 2010)
Summary
Diseases caused by pathogenic bacteria and fungi present critical problem to human health and are one of the main causes of morbidity and mortality worldwide (WHO, 1998). Rence of toxicity during prolonged treatment with present day drugs have been the reasons for extended search for newer drugs to treat microbial infections (Fostel and Lartey, 2000). Combination therapy is an alternative approach in the search for novel compounds with ability to deal with antibiotic resistant microorganisms. Studies have shown that plant extracts in combination of two or more are yielding effective antimicrobial activity against several microorganisms that even include drug resistant bacteria (Karmegam et al, 2008). Plants have been used to treat infectious diseases due to their antimicrobial properties. This is due to the presence of various kinds of phytochemicals including phenolic compounds, alkaloids, terpenoids and essential oils (Lewis and Elvin-Lewis, 1995; Cowan, 1999)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
