Antimicrobial activity

In this study, in vitro antimicrobial activity of Polyherbal cream comprising of various plant herb extracts of leaves viz. Aloe barbadensis, Calendula officinalis, Lawsonia inermis, Carica Papaya and Azadirachta indica along with tridax procumbens as a key Plant was evaluated. Polyherbal formulations (F1 & F2) were designed and developed as ointment based semisolid cream. Disc diffusion method and agar well diffusion method were used for in vitro antibacterial and antifungal screening for both the formulations. Zone of inhibition were observed as a measure of investigation. The Formulation-1 (F1) showed efficient zone of inhibition at concentration of 4% than the formulation-2 (F2) at lower concentration 2% of tridax procumbens. In antifungal screening, the compound showed significant zones of inhibition against tested fungi.

The present paper represents an attempt to investigate the effect of the geographical location on the yield percent and antimicrobial activity of the essential oils of Cyperus rotundus. The  essential oils of the plant were collected in five different locations in Sudan, namely Dongola (northern Sudan); Darfour (western Sudan); Aljazeera and Khartoum (central Sudan) and Sinnar (eastern Sudan) and prepared by hydro -distillation technique. The percentage yields were found to be variable according to the growing location. The highest yield was found in the Dongola sample (1.2%) and the lowest in Khartoum and Aljazeera samples (0.5%). The antimicrobial activities of the prepared essential oils were also variable with regard to the sample tested .The highest antimicrobial activity was found in Khartoum oil sample followed by Darfour oil sample; Dongola oil sample; Aljazeera and Khartoum oil samples and finally Sinnar oil sample.

1, 4-diazabicyclo [2.2.2] octane (DABCO) as an efficient organocatalyst were used for synthesis of annulated uracil derivatives via one-pot three component condensation reactions of substituted aromatic aldehydes, malononitrile and barbituric acid in aqueous ethanol carried at NTP. This is rapid, efficient synthetic route with several advantages viz; operational simplicity, mild reaction conditions, high yields of the biological active products, uses less toxic solvents and cheap catalyst. The synthesized products were screened for antimicrobial activity. Therefore annulated uracil derivatives   are excellent antimicrobial agents for globally alarming drug resistance issues in clinically used therapeutics.

The rapid spread of multidrug-resistance against conventional antibiotics is a global threat that necessitates the search for alternative therapies from natural sources. In this investigation, the antibacterial potentials of ethanol extracts of moth beam (Vigna aconitifolia)  extracts were evaluated against Bacillus subtilis, Staphylococcus aureus, Staphylococcus werneri, Pseudomonas aeruginosa and Escherichia coli, Proteus mirabilis, Kleibsella pneumonia, Pseudomonas putida, using Agar cup-plate method. The extract showed  antimicrobial  activities  against  all  the  tested  gram positive and  gram negative  bacteria. Ethanol extracts in general exhibited greater antibacterial activity and results were comparable to the standard. Our finding identifies the potential use of moth bean as a natural source of antibacterial agent. Further studies are warranted to elucidate the mechanism of action of the extracts and to identify the active components responsible for the antibacterial activity.

The present study deals with the isolation, screening and characterization of the actinomycetes from the marine sediments, which were collected from different locations of Bay of Bengal. Selective media and the pre-treatment strategies enhanced the isolation and screening of novel marine actinomycetes. A total of 8 marine samples were collected. The pre-heat treatment method and a combination of 4 enrichment media were found to be effective in selectively isolating marine actinomycetes. The top six potent isolates were subjected to detailed morphological, cultural, biochemical and physiological characterization. A total of 63 isolates were isolated. The antimicrobial activity was studied for all the 63 isolates. The preliminary study of 63 isolates for antimicrobial activity by cross streak method indicated that 42 isolates had antagonistic properties. All these 42 isolates were subjected to submerged fermentation studies. It was observed that 12 isolates exhibited antibacterial activity, 6 isolates showed antifungal activity whereas 6 isolates exhibited both antibacterial and antifungal activities. The present study was an attempt to use different methods to screen, select and isolate marine actinomycetes from the sediments of Bay of Bengal with intrinsic antimicrobial activity against a variety of microbial pathogens.

In most parts of Nigeria, traditional medicine practitioners and most rural dwellers use plant parts for treatment of ailments without scientific proof. This study was designed to investigate the antimicrobial activities of the aqueous and ethanol root extracts of Anogeissus leiocarpus against Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 10145, Bacillus subtilis NCTC 8236, Staphylococcus aureus ATCC 25923, Candida albicans 24433 and clinical isolates of Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus, Klebsiella spp and Candida albicans. The antimicrobial assays were carried out using the agar ditch diffusion and agar well diffusion methods. Statistical analysis was done using two way anova without replication. The ethanol extract inhibited all organisms and had lower minimum inhibitory concentrations (MIC) compared to the aqueous extract (P < 0.05). Staphylococcus aureus recorded the lowest MIC in ethanol and aqueous extract while Klebsiella spp had the highest MIC in ethanol extract. The aqueous extract had no activity against Candida albicans ATCC 24433. The use of this plant root alone and in combination with other plants by herb medicine practitioners for the treatment of infectious diseases can therefore be justified. However further work should carried out to isolate the active component that furnishes the understudied plant with its antimicrobial potential and as well determine the toxicity of the plant.

Sulfones are known to possess various biological activities. Their great potential as bioactive compounds, combined with the easy method of synthesis, make this class a strong candidate for the production of medicines economically. This article deals with the synthesis of a series of ten diaryl sulfones, their antibacterial activity, individually, synergistic antibacterial activity with trimethoprim against E. coli and preliminary QSAR studies. The antibacterial activity was performed by agar diffusion method, against Gram positive and Gram negative bacteria. Few derivatives exhibited antibacterial activity comparable to or better than the standard, sulphamethoxazole, against Gram negative organisms (E. coli and S. dysentrae). Sulfones being folic acid inhibitors, their synergistic effect was checked with trimethoprim on E. coli. Most of the compounds exhibited synergistic effect with trimethoprim, which was better than the combination of trimethoprim and sulfamethoxazole (1:5). Quantitative structure activity relationships studies were performed by multiple linear regression analysis. The antibacterial activity of sulfones was found to correlate well with their dipole moment and ionization potential.

Grewia asiatica Linn. belonging to family Tiliaceae is commonly known as Phalsa found through out India. It is an important medicinal plant used in inflammation, diabetes, fever, blood disorders, cooling agent, astringent, postural eruption etc. As a herb it is used widely in the Indian traditional system, it was thought worthwhile to undertake the standardization of its aerial parts. Evaluation of the leaves were carried out to determine the effect of various drug extract on number of microbial and fungal strain. Leaves exhibited moderate to significant antibacterial and antifungal activity against all the tested bacterial strains. The chloroform extract exhibited moderate antibacterial and antifungal activity. The petroleum ether extract was devoid of any antibacterial and antifungal activity. While mentioned all the organisms are susceptible to alcoholic as well as  aqueous extracts.

Several pharmacological activities like antitubercular, analgesic, anti-cancer, anti-inflammatory, antiasthmatic, antioxidant and antibacterial activities have been attributed to pyrazoles. The above observations prompted us to synthesize some novel pyrazole derivatives as possible antimicrobial agents. A series of novel 1,3,5-trisubstituted pyrazole derivatives (P1-P15) have been synthesized by the reaction of substituted chalcones (C1-C15) with succinichydrazide. The starting material, chalcones were prepared by claisen Schmidt condensation of acetophenone with aldehydes in the presence of sodium hydroxide in ethanol. Succinichydrazide was synthesized by condensing succinic acid with hydrazine hydrate. The cycloaddition of chalcones with succinichydrazide gives 1,3,5-trisubstituted pyrazole derivatives. The structures of synthesized derivatives were confirmed by IR, 1HNMR and Mass spectrum. The synthesized compounds were screened for their antibacterial and antifungal activity. The antibacterial activity data of the synthesized derivatives revealed that the compound P4, P13 and P7, P14 were effective against gram positive and gram negative organisms respectively. The antifungal activity data revealed that the compound P7 and P8 showed good activity against tested fungi.

An efficient and rapid synthesis of some new pyrazoles, isoxazole, benzoxazepine and benzothiazepine derivatives is described. The synthesized compounds were investigated for their anti-inflammatory and antimicrobial activities and some of them showed potent anti-inflammatory and anti-microbial activities.