Isatin-derived antibacterial and antifungal compounds and their transition metal complexes.

A series of isatins incorporating thiazole, thiadiazole, benzothiazole and p-toluene sulfonyl hydrazide moieties, along with their cobalt(II), copper(II), nickel(II) and zinc(II) metal complexes have been synthesized and characterized by elemental analyses, molar conductances, magnetic moments, IR, NMR and electronic spectral data. These compounds have been screened for antibacterial activity against Escherichia coli, Bacillus subtillis, Shigella flexneri, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella typhi, and for antifungal activity against Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani and Candida glaberata using the agar-well diffusion method. All the synthesized compounds have shown good affinity as antibacterial and/or antifungal agents which increased in most of the cases on complexation with the metal ions

Microwave-assisted solvent free efficient synthesis of 1,3,4-oxadiazole-2(3H)-thiones and their potent in vitro urease inhibition activity

An efficient solvent free microwave assisted synthesis of 5-substituted-1,3,4-oxadiazole-2(3H)-thiones (2a-2r) from hydrazides and carbon disulfide has been accomplished in good to excellent yield. The urease inhibition activity of the resulting compounds was investigated. Preliminary bioassay indicated that the compound 2j bearing 2-bromo substituent is the most active inhibitor exhibiting IC50 12.60 ± 0.92 μM

Muscle Relaxant and Sedative-Hypnotic Activities of Extract of Viola betonicifolia in Animal Models Supported by Its Isolated Compound, 4-Hydroxy Coumarin

The crude methanolic extract of the whole plant of Viola betonicifolia (VBME) was investigated for anxiolytic, muscle relaxant, sleep induction, antidepressant, and sedative activities) to ascertain its scientific values. VBME showed a significant ( < 0.05) dose dependent anxiolytic action in staircase test. In muscle relaxant paradigms, a dose dependent muscle relaxation was observed. For phenobarbitone sleep induction test, VBME notably ( < 0.05) reduced the latency time and increased total sleeping duration. Our tested extract was found free of any antidepressant activity, while the movement was significantly ( < 0.05) shortened in locomotor activity. The whole plant of V. betonicifolia led to the isolation of 4-hydroxyl coumarin (4HC) which showed substantial safety profile in acute toxicity test. When challenged in Traction and Chimney tests, it showed significant ( < 0.05) muscle relaxant effect in both muscle relaxant paradigms at 20 and 30 mg/kg during various assessment times. Nevertheless, 4HC was devoid of sedative and hypnotic potentials. In conclusion, VBME had strong muscle relaxant and sedative-hypnotic properties, while its isolated compound, 4HC, possessed a significant muscle relaxant action with substantial safety profile without sedative-hypnotic effects

Phytochemical screening, free radical scavenging, antioxidant activity and phenolic content of Dodonaea viscosa

The purpose of this study was to evaluate the antioxidant potential of Dodonaea viscosa Jacq. Methanolic extract of the plant was dissolved in distilled water and partitioned with n-hexane, chloroform, ethyl acetate and nbutanol sequentially. Phytochemical screening showed presence of phenolics, flavonoides and cardiac glycosides in large amount in chloroform, ethyl acetate and n-butanol fraction. The antioxidant potential of all these fractions and remaining aqueous fraction was evaluated by four methods: 1,1-Diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, total antioxidant activity, Ferric Reducing Antioxidant Power (FRAP) assay and ferric thiocyanate assay along with determination of their total phenolics. The results revealed that ethyl acetate soluble fraction exhibited highest percent inhibition of DPPH radical as compared to other fractions. It showed 81.14 ± 1.38% inhibition of DPPH radical at a concentration of 60 μg/ml. The IC50 of this fraction was found to be 33.95 ± 0.58 μg/ml, relative to butylated hydroxytoluene (BHT), having IC50 of 12.54 ± 0.89 μg/mL. It also showed highest FRAP value (380.53 ± 0.74 μM of trolox equivalents) as well as highest total phenolic contents (208.58 ± 1.83 GAE μg/g) and highest value of inhibition of lipid peroxidation (58.11 ± 1.49% at concentration of 500 μg/ml) as compared to the other studied fractions. The chloroform fraction showed highest total antioxidant activity i.e.1.078 ± 0.59 (eq. to BHT)

A Thermoelectric Energy Harvesting System

Thermoelectric generators (TEGs) and their applications have gained momentum for their ability to use waste thermal energy. More contemporary technology must offer more exceptional energy-efficient applications at a lower cost. New technology must also have an ability to generate electric power through the conversion of wasted heat. The TEG has demonstrated its efficiency and how it can offer increased potential by adding an MPPT algorithm to increase the power flow while decreasing the cost of operation. The limitations can be offset by the use of lower cost manufacturing materials and automated systems in the TEG units. It is also important to note the cost per watt found in using a thermoelectric generator is estimated to be $1/W for an installed device. To achieve this goal, the optimum operating point should be monitored by DC to DC converters. The DC to DC converters should also be driven through a generated pulse using an MPPT algorithm

Acetone sensor based on solvothermally prepared ZnO doped with Co3O4 nanorods

This paper describes a reliable and sensitive method for sensing dissolved acetone using doped nanomaterials. Large-scale synthesis of ZnO nanorods (NRs) doped with Co(3)O(4) was accomplished by a solvothermal method at low temperature. The doped NRs were characterized in terms of their morphological, structural, and optical properties by using field-emission scanning electron microscopy coupled with energy-dispersive system, UV-Vis., Fourier transform IR, X-ray diffraction, and Xray photoelectron spectroscopy. The calcinated (at 400 °C) doped NRs are shown to be an attractive semiconductor nanomaterial for detecting acetone in aqueous solution using silver electrodes. The sensor exhibits excellent sensitivity, stability and reproducibility. The calibration plot is linear over a large concentration range (66.8 μM to 0.133 mM), displays high sensitivity (~3.58 μA cm(−2) mM(−1)) and a low detection limit (~14.7 ± 0.2 μM; at SNR of 3). [Figure: see text

Molecular epidemiology of clinical and carrier strains of methicillin resistant Staphylococcus aureus (MRSA) in the hospital settings of north India

BACKGROUND: The study was conducted between 2000 and 2003 on 750 human subjects, yielding 850 strains of staphylococci from clinical specimens (575), nasal cultures of hospitalized patients (100) and eye & nasal sources of hospital workers (50 & 125 respectively) in order to determine their epidemiology, acquisition and dissemination of resistance genes. METHODS: Organisms from clinical samples were isolated, cultured and identified as per the standard routine procedures. Susceptibility was measured by the agar diffusion method, as recommended by the Nat ional Committee for Clinical Laboratory Standards (NCCLS). The modified method of Birnboin and Takahashi was used for isolation of plasmids from staphylococci. Pulsed-field gel electrophoresis (PFGE) typing of clinical and carrier Methicillin resistant Staphylococcus aureus (MRSA) strains isolated during our study was performed as described previously. RESULTS: It was shown that 35.1% of Staphylococcus aureus and 22.5% of coagulase-negative staphylococcal isolates were resistant to methicillin. Highest percentage of MRSA (35.5%) was found in pus specimens (n = 151). The multiple drug resistance of all MRSA (n = 180) and Methicillin resistant Coagulase-negative Staphylococcus aureus (MRCNS) (n = 76) isolates was detected. In case of both methicillin-resistant as well as methicillin-sensitive Saphylococcal isolates zero resistance was found to vancomycin where as highest resistance was found to penicillin G followed by ampicillin. It was shown that the major reservoir of methicillin resistant staphylococci in hospitals are colonized/infected inpatients and colonized hospital workers, with carriers at risk for developing endogenous infection or transmitting infection to health care workers and patients. The results were confirmed by molecular typing using PFGE by SmaI-digestion. It was shown that the resistant markers G and T got transferred from clinical S. aureus (JS-105) to carrier S. aureus (JN-49) and the ciprofloxacin (Cf) and erythromycin (E) resistance seemed to be chromosomal mediated. In one of the experiments, plasmid pJMR1O from Staphylococcus aureus coding for ampicillin (A), gentamicin (G) and amikacin (Ak) resistance was transformed into Escherichia coli. The minimal inhibitory concentrations (MICs) for A and G were lower in E. coli than in S. aureus. However, the MIC for Ak was higher in E. coli transformants than in S. aureus. CONCLUSION: There is a progressive increase in MRSA prevalence and multi-drug resistance in staphylococci. Vancomycin is still the drug of choice for MRSA infections. The major reservoir of methicillin resistant staphylococci in hospitals is colonized/infected inpatients and colonized hospital workers. Resistance transfer from staphylococci to E. coli as well as from clinical to carrier staphylococci due to antibiotic stress seemed to be an alarming threat to antimicrobial chemotherapy

In vitro assessment of the antifungal effects of neem powder added to polymethyl methacrylate denture base material

Denture with antimicrobial activities is desirable to prevent Candida albican adhesion subsequently decreasing the susceptibility of denture stomatitis incidence. Azadirachta Indica, commonly known as Neem powder has antimicrobial effect but the effect of its addition to acrylic denture base on C. albicans adhesion has not been investigated. The aim of this study was determine whether adding neem powder to acrylic denture base materials could reduce Candida albicansadhesion. One hundred and twenty acrylic resin denture specimens were fabricated and divided into heat-polymerized (n=60) and auto-polymerized (n=60) groups. Each group was further divided into 6 groups (n=10) based on the neem concentration: 0, 0.5, 1, 1.5, 2 and 2.5 wt% of the polymer. After polymerization, the specimens were polished, stored in distilled water, sonicated, sterilized, submerged in artificial saliva containing C. albicans, and finally, placed in an incubator at 37°C. Slide counting and direct culture methods were used to assess the antifungal effects of the neem addition. An analysis of variance and post hoc Tukey?s test were performed for the data analysis (p?0.05 was statistically significant). Based on the results, the neem addition significantly decreased the C. albicans count when compared to the control group (p?0.05). Moreover, the count decreased as the neem concentration increased (lowest count with 2.5 wt%). The results suggest that adding neem powder to acrylic resin denture base materials reduces the adhesion of C. albicans; therefore, the incorporation of neem could be a possible denture stomatitis prevention method