ABSTRACT
Withania somnifera (L.) Dunal (Solanaceae), commonly known as Ashwagandha, is one of the most valued Indian medicinal plants with a number of pharmaceutical and nutraceutical applications. Metabolic profiling has been performed by HR-MAS NMR spectroscopy on fresh leaf and root tissue specimens from four chemotypes of W. somnifera. The HR-MAS NMR spectroscopy of lyophilized defatted leaf tissue specimens clearly distinguishes resonances of medicinally important secondary metabolites (withaferin A and withanone) and its distinctive quantitative variability among the chemotypes. A total of 41 metabolites were identified from both the leaf and root tissues of the chemotypes. The presence of methanol in leaf and root tissues of W. somnifera was detected by HR-MAS NMR spectroscopy. Multivariate principal component analysis (PCA) on HR-MAS (1) H NMR spectra of leaves revealed clear variations in primary metabolites among the chemotypes. The results of the present study demonstrated an efficient method, which can be utilized for metabolite profiling of primary and secondary metabolites in medicinally important plants.
Subject(s)
Nuclear Magnetic Resonance, Biomolecular/methods , Plant Leaves/chemistry , Plant Roots/chemistry , Withania/chemistry , Methanol/chemistry , Multivariate Analysis , Plant Leaves/metabolism , Plant Roots/metabolism , Withania/metabolismABSTRACT
Tea leaves are known for its antibacterial activity against many microorganisms. In this study we attempted to describe the synergistic antimicrobial activity of tea and antibiotics against enteropathogens. Antimicrobial activity of boiled water tea extract and organic solvent extract were studied against Salmonella typhimurium 1402/84, S. typhi, S. typhi Ty2a, Shigella dysenteriae, Yersinia enterocolitica C770, and Escherichia coli (EPEC P2 1265) determining minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and death rate kinetics at MBC of tea extract in presence of subinhibitory concentration of antibiotic. Both green tea or black tea extracts effectively inhibited the growth of S. typhimurium 1402/84, S. typhi, S. typhi Ty2a, S. dysenteriae, Y. enterocolitica C770, and E.coli (EPEC P2 1265). However, the growth inhibitory concentration of tea extract was lower for green tea as compared to black tea extract. Antimicrobial activity of green tea tea methanol: water extract tea was better as compared to boiled water tea extract of green tea. Based on death rate kinetics results, S.typhi Ty2a appeared to be highly sensitive and Y. enterocolitica C770 the most resistant. Chloramphenicol and tea extract in combination inhibited the growth of S.dysenteriae at 2.5 microg/ml chloramphenicol (MIC 5 microg/ml) and 5.094 mg/ml black tea extract (MIC 9.089 mg/ml). Tea extract showed synergistic activity with chloramphenicol and other antibiotics like gentamycin, methicillin and nalidixic acid against test strains.