National Institute of Standards and Technology における超伝導研究及び生活

Differently substituted flavanones were isolated from Leguminosae and their antibacterial activity was comparatively studied against methicillin-resistant Staphylococcus aureus (MRSA). The minimum inhibitory concentrations (MICs) of phytochemical flavanones to clinical isolates of MRSA were determined by a serial agar dilution method. The structure-activity relationship has indicated that 2',4'- or 2',6'-dihydroxylation of the B ring and 5,7-dihydroxylation of the A ring in the flavanone structure are important for significant anti-MRSA activity and that substitution with a certain aliphatic group at the 6- or 8-position also enhances the activity. Among the thirteen flavanones tested, tetrahydroxyflavanones with these structural characteristics isolated from Sophora exigua and Echinosophora koreensis showed intensive activity to inhibit the growth of all MRSA strains at 3.13-6.25 micrograms/ml. The present hydroxyflavanones would be useful in the phytotherapeutic strategy against MRSA infections.

Comparative Study on the Antibacterial Activity of Phytochemical Flavanones against Methicillin-resistant Staphylococcus aureus.

OBJECTIVE: To evaluate the antibacterial potential of aqueous and acetone extracts of galls of Quercus infectoria by determination of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values. 
MATERIALS AND METHODS: The extracts from the galls of Q. infectoria at 10 mg/ml were screened against three Gram-positive bacteria (Staphylococcus aureus ATCC 25923, Staphylococcus epidermidis and Bacillus subtilis) and three Gram-negative bacteria (Escherichia coli NCTC 12079 serotype O157:H7, Salmonella typhimurium NCTC 74 and Pseudomonas aeruginosa ATCC 27853). The MIC of the extracts were then determined using the twofold serial microdilution technique at a concentration ranging from 5 mg/ml to 0.0024 mg/ml. The MBC values were finally obtained from the MIC microtiter wells which showed no turbidity after 24 hrs of incubation by subculturing method. 
RESULTS: Out of the six bacterial species tested, S. aureus was the most susceptible. On the other hand, the extracts showed weak inhibitory effect against S. epidermidis, B. subtilis, S. typhimurium and P. aeruginosa while there was no inhibition zone observed for E. coli O157. The MIC values of the extracts ranged from 0.0781 mg/ml to 1.25 mg/ml whereas the MBC values ranged from 0.3125 mg/ml to 2.50 mg/ml. The MBC values of aqueous extract against S. aureus and S. typhimurium were higher than their MIC values. The MBC value of acetone extract against S. aureus was also higher than its MIC value. Interestingly, however, the MIC and MBC values of acetone extract against S. typhimurium were the same (1.25 mg/ml). 
CONCLUSION: The aqueous and acetone extracts displayed similarities in their antimicrobial activity on the bacterial species and as such, the galls of Quercus infectoria are potentially good source of antimicrobial agents.

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Research Paper - The potential of aqueous and acetone extracts of galls of Quercus infectoria as antibacterial agents

Preparation, characterization and antifungal activity of iron oxide nanoparticles

CMC stabilized nano silver synthesis, characterization and its antibacterial and synergistic effect with broad spectrum antibiotics

https://memberfiles.freewebs.com/18/39/96893918/documents/Cychoz.pdf

Antimicrobial Activity of the Crude Extracts of Withania somnifera and Cenchrus setigerus In-vitro

Crude extracts of different parts (root, stem, leaf and seed) of Cenchrus ciliaris (CAZRI-358) and (Unripen fruit, ripen fruit and calyx) of Withania somnifera (RUBL-20668) were successively extracted with polar to non polar solvents using soxhlet assembly. The extracts were then screened for their Biological activity in-vitro against one gram positive bacteria (Staphylococcus aureus), two gram negative bacteria (Escherichia coli and Raoultella planticola) and one yeast (Candida albicans) by disc diffusion assay. Serial dilution method was used to determine minimum inhibitory concentration (MIC) and minimum bactericidal/ fungicidal concentration (MBC/MFC). Water extract of Unripen fruit of W. somnifera showed highest antibacterial activity (IZ-13.33±0.24 mm, AI- 0.833) and highest antifungal activity (IZ-18.67±0.22 mm, AI- 2.667) against E. coli and C. albicans respectively as well as chloroform extract of stem (IZ-12.50±0.64 mm, AI- 1.042) and seeds (IZ-10.67±0.23 mm, AI- 0.821) of C. ciliaris against C. albicans and S. aureus.

Phyto-chemical Screening and Antimicrobial Activities of Dhaman grass and Indian Ginseng

Crude extracts of different parts of Withania somnifera (RUBL-20668) and Cenchrus setigerus (CAZRI-76) were successively extracted with polar to non polar solvents using soxhlet assembly. The extracts were then screened for their Biological activity in-vitro against one Gram positive bacteria (Staphylococcus aureus), two gram negative bacteria (Escherichia coli and Raoultella planticola) and one yeast (Candida albicans) by disc diffusion assay. Serial dilution method was used to determine minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal concentration (MBC/MFC). Water extract of leaves of W. somnifera showed highest activity against R. planticola and chloroform extract of stem of C. setigerus showed highest activity against S. aureus.

COMPARATIVE MICROCIDAL ACTIVITY OF WITHANIA SOMNIFERA AND CENCHRUS SETIGERUS AGAINST THE PATHOGENIC MICRO-ORGANISMS Research Article

The aim of present study is to investigate the antimicrobial activity of Cenchrus ciliaris (CAZRI-358) and Cenchrus setigerus (CAZRI76) in order to use it as a possible source for new antimicrobial substances against important human pathogens. Crude extracts of leaf of C. ciliaris and C. setigerus were evaluated against six medically important bacteria viz. Escherichia coli (Gram-ve), Raoultella planticola (Gram-ve), Staphylococcus aureus (Gram +ve), Pseudomonas aeruginosa (Gram-ve), Bacillus Subtilis (Gram +ve), Enterobactor aerogens (Gram-ve), one yeast Candida albicans and one fungi Aspergillus flavus. The dried and powdered leaves were successively extracted with hexane, toluene, isopropyl alcohol, acetone and ethanol using soxhlet assembly. The antimicrobial activity assay was done by both disc diffusion and serial dilution methods. Iso propyl alcohol extract of C. ciliaris (CAZRI-358) showed highest activity against Staphylococcus aureus. Disc diffusion and serial dilution methods were used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal concentration (MBC/MFC) at concentrations of 0.469mg/ml to 15mg/ml. Iso propyl alcohol extract of C. ciliaris was the most active one with MIC of 0.469mg/ml against R. planticola. The present investigation provides a scientific basis for the use of these plant extracts in home-made remedies and their possible application against micro-organisms.

Bio activity of crude extracts of leaves of cenchrus grass in different polar solvents against some pathogenic microbes

The stems of Cenchrus ciliaris (CAZRI-358) and Cenchrus setigerus (CAZRI-76) were evaluated against medically important bacteria viz. Proteus merabilis, Klebsiella pnemoniae, Agerobacterium tumefaciens and one fungi Aspergillus niger. The dried and powdered stems were successively extracted with a series of non polar to polar solvents using soxhlet assembly. The antimicrobial assay was done by both disc diffusion and serial dilution methods. Glacial acetic acid extract of C. ciliaris showed highest activity against P. merabilis to varying degrees, but it had no inhibitory effect on fungal species (Aspergillus niger) by any extract of both the grasses. Gentamycin, the standard antibacterial drug used was effective in inhibiting these bacteria. The effect on P. merabilis and A. tumefaciens were comparable to that of gentamycin. Ketoconazole the standard anti fungi used was effective against the fungi. The extract of Cenchrus grasses also significantly (P>0.005) inhibited the bacterial growth. The inhibitory effect is very identical in magnitude and comparable with that of standard antibiotics used.

Premlata Singariya

Papers

Antimicrobial Activity of the Crude Extracts of Withania somnifera and Cenchrus setigerus In-vitro

Phyto-chemical Screening and Antimicrobial Activities of Dhaman grass and Indian Ginseng

COMPARATIVE MICROCIDAL ACTIVITY OF WITHANIA SOMNIFERA AND CENCHRUS SETIGERUS AGAINST THE PATHOGENIC MICRO-ORGANISMS Research Article

Bio activity of crude extracts of leaves of cenchrus grass in different polar solvents against some pathogenic microbes

Evaluation of antibacterial activity and preliminary phytochemical studies on the stem of cenchrus ciliaris and cenchrus setigerus