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This study investigated the effects of lactic acid bacteria (LAB) of goat's milk origin on growth and biofilm formation of two pathogenic strains viz. Pseudomonas aeruginosa and Staphylococcus aureus . Different LAB preparations such as untreated cell free supernatants (CFSs), pH neutralized CFS (N-CFS) and heat treated CFS (H-CFS) of lactobacilli were screened for their antimicrobial and biofilm inhibitory properties. The antagonistic activities were compared to L . acidophilus , a reference probiotic strain. In addition, metabolic activity of bacterial pathogens upon CFSs challenge was also determined by MTT assay. LAB CFSs inhibited pathogen growth to a varied degree. A decrease in the number of sessile pathogen cells was observed upon exposure with untreated CFS, under both post and co-incubation strategy. The CFS of GM12, GM13, GM15 and GM17 could effectively inhibit the biofilm formation of both the pathogens to a significant level (p < 0.05) varying between 72% and 86%. Upon principal component analysis of recorded data, untreated CFS from GM12 emerged to be most promising against both the test biofilm formers. N-CFS and H-CFS preparations also limited the biofilm formation, however to a lower extent than untreated form. As also determined by MTT assay, the metabolic activity of P. aeruginosa and S. aureus were significantly reduced upon CFS exposure. The light microscopic images depicted major disruption in the biofilm matrix of pathogenic strains upon CFS challenge. Findings from this study indicate that the Lactobacillus strains of goat milk origin screened in this study may serve as bio-control agents for prophylactic use to prevent infections. [ABSTRACT FROM AUTHOR]

This study was undertaken to assess the antibacterial efficacy of lactobacilli isolated from curd and human milk samples. Identities of thirty-one different lactobacilli (20 from curd and 11 from human milk) were confirmed by genus-specific PCR and 16S rRNA-based sequencing. These strains belonged to five species, Lactobacillus casei, L. delbrueckii, L. fermentum, L. plantarum, and L. pentosus. Antibacterial activities of cell-free supernatants (CFSs) of all the Lactobacillus isolates were estimated through standard agar-well diffusion assay, against commonly occurring food-borne and clinically important human pathogens. None of the lactobacilli cell-free supernatant (CFS) exhibited inhibitory activity against four pathogens, namely Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, and Klebsiella pneumoniae. Bacillus cereus, Salmonella enterica serovar Typhi, and Shigella flexneri were moderately inhibited by majority of CFSs, whereas, weak activity was observed against Pseudomonas aeruginosa and Proteus mirabilis. CFS of some of the curd isolates displayed antagonistic activity against Streptococcus mutans; however, human milk lactobacilli did not displayed any inhibitory activity against them. As expected, Nisin (Nisaplin) showed inhibitory activity against Gram-positive, S. aureus, B. cereus, and L. monocytogenes. Interestingly, few of the examined CFSs exhibited inhibitory activities against both Gram-positive and Gram-negative pathogens. Findings from this study support the possibility to explore the tested lactobacilli and their CFSs as natural bio-preservatives, alone or in combination with approved bacteriocins in food and pharma formulations after validating their safety. [ABSTRACT FROM AUTHOR]

Herein, we describe a one-pot synthesis of some novel 2-(3-alkyl/aryl-5-trifluoromethylpyrazol-1-yl)-4-(coumarin-3-yl)thiazoles(6)involving the reaction of 3-alkyl/aryl-5-hydroxy-5-trifluoromethyl-4,5-dihydropyrazole-1-thiocarboxamides(3)with 3-bromoacetylcoumarins(5)in the presence of sodium carbonate in ethanol. Reaction of3with5in the absence of sodium carbonate, however, resulted in the formation of 2-(3-alkyl/aryl-5-hydroxy-5-trifluoromethyl-4,5-dihydropyrazol-1-yl)-4-(coumarin-3-yl)thiazoles, which were subsequently dehydrated to6by refluxing in ethanol in the presence of sodium carbonate. The structure of the synthesized compounds (6) was confirmed by infrared (IR), mass,1H NMR, and13C NMR spectra and elemental analysis data. Newly synthesized compounds (6) showed moderate to good activity against Gram-positive bacteria. [ABSTRACT FROM AUTHOR]

A series of new unsymmetrical 2,5-disubstituted 1,3,4-oxadiazoles ( 3a- d) has been synthesized to evaluate their antibacterial and thermal properties. All compounds have been tested for their in vitro antibacterial activity against two Gram-positive bacteria namely, Staphylococcus aureus and Bacillus subtilis. Among the tested compounds, compound 2-(4-chlorophenyl)-5-(thiophen-2-yl)-1,3,4-oxadiazole ( 3c) has been found to be most potent member having minimum inhibitory concentration. Thermal stability and melting point of compounds have been studied by TG and DSC analysis in air atmosphere at heating rate of 10 °C min. Thermal degradation kinetics of the most potent antibacterial compound 3c has been carried out by multiple heating rate model free kinetic methods namely, Ozawa-Flynn-Wall, modified Coats-Redfern, and Kissinger. [ABSTRACT FROM AUTHOR]

A series of new symmetrical 3,6- bis(aryl) bis([1,2,4]triazolo)[3,4-a:4′,3′-c]phthalazines 9a-l has been conveniently synthesized by oxidative cyclization of 1,4- bis(substituted benzalhydrazino)phthalazines 8a-l promoted by iodobenzene diacetate under mild conditions (12 examples, up to 93% yield). All the 12 compounds were tested in vitro for their antibacterial activity against two Gram-positive bacteria, namely, Staphylococcus aureus, Bacillus subtilis and two Gram-negative bacteria, namely, Escherichia coli and Pseudomonas aeruginosa. All the synthesized compounds were also tested for their antifungal action against two fungi, Aspergillus niger and Aspergillus flavus. [ABSTRACT FROM AUTHOR]

A series of macrocyclic complexes are synthesized by condensation of acetonylacetone and carbohydrazide in the presence of divalent metal salts in methanol. The complexes are [M(TML)X2], where M = Co(II), Ni(II), Cu(II), and Zn(II); X = Cl-, [image omitted], CH3COO- and TML is a tetradentate macrocyclic ligand. The complexes have been characterized by elemental analyses, conductance measurements, magnetic measurements, NMR, infrared, and electronic spectral studies. The low value of molar conductance indicates non-electrolytes. A six-coordinate geometry with trans coordination of monodentate ligands may be proposed for all the complexes. All the metal complexes were also tested for their in vitro antibacterial activities against some bacterial strains. The results obtained were compared with standard antibiotic, Ciprofloxacin. Some of the tested complexes show good antibacterial activities against some bacterial strains. [ABSTRACT FROM AUTHOR]

The Schiff bases HL1-3 have been prepared by the reaction of 5-bromothiophene-2-carboxaldehyde with 4-amino-5-mercapto-3- methyl/propyl/isopropyl-s-triazole, respectively. Organosilicon(IV) and organotin(IV) complexes of formulae (CH3)2MCl(L1-3), (CH3)2M(L1-3)2 were synthesized from the reaction of (CH3)2MCl2 and the Schiff bases in 1 : 1 and 1 : 2 molar ratio, where M = Si and Sn. The synthesized Schiff bases and their metal complexes have been characterized with the aid of various physicochemical techniques like elemental analyses, molar conductance, UV, IR, ¹H, 13C, 29Si, and 119Sn NMR spectroscopy. Based on these studies, the trigonal bipyramidal and octahedral geometries have been proposed for these complexes. The ligands and their metal complexes have been screened in vitro against some bacteria and fungi. [ABSTRACT FROM AUTHOR]

Aim: To assess the antimicrobial efficacy of five solvent extracts of two Piper species commonly used in diet and traditional medicine, P. cubeba and P. longum, against selected bacterial and oral fungal pathogens i.e. Streptococcus mutans, Staphylococcus aureus, Candida albicans and Saccharomyces cerevisiae. Methods: The antimicrobial activity of five extracts of cubeb berries and Indian long pepper fruits was determined by the agar well diffusion method. The minimum inhibitory concentration (MIC) for the acetonic, methanolic and ethanolic extracts was determined by the modified agar well diffusion method. Results: Of the 5 fruit extracts evaluated, acetone, ethanol and methanol extracts of both the Piper spp. were found to have variable antimicrobial activities against all the four oral pathogens. The acetonic fruit extract of P. cubeba was the most effective against both the yeasts with the highest zone of inhibition (15.31 mm) against C. albicans followed by the methanolic (12.31 mm) and ethanolic (11.94 mm) extracts. C. albicans was found to be most sensitive pathogen, which survived up to 6.25 mg/mL in the acetonic extract (MIC = 12.5 mg/mL) followed by the methanolic and ethanolic extracts (MIC = 25 mg/mL). The acetonic, methanolic and ethanolic extracts of P. longum fruits showed almost equal inhibition zones of both yeasts, ranging between 10.64 and 14 mm. C. albicans survived up to 12.5 mg/mL (MIC= 25 mg/mL) while S. cerevisiae survived up to 25 mg/mL (MIC = 50 mg/mL). Conclusions: The crude extracts obtained from the fruits of the two Piper spp. may be used to treat oral fungal species, especially C. albicans, as they produced larger inhibition zones than antifungal drugs often used to treat these pathogens. [ABSTRACT FROM AUTHOR]

A novel series of complexes of the type [M(C36H22N6)X]X2, where M = Cr(III), Mn(III), Fe(III); X = Cl−, NO3−, CH3COO−; and (C36H22N6) corresponds to the tetradentate macrocyclic ligand, have been synthesized by condensation of 1,8-diaminonaphthalene and isatin in the presence of trivalent metal salts in methanolic medium. The complexes have been characterized by elemental analysis, conductance and magnetic measurements, and UV/Vis, IR, and mass spectroscopy. On the basis of these studies, a five coordinate square pyramidal geometry for all of these complexes is proposed. All synthesized macrocyclic complexes have been tested for in vitro antimicrobial activities against some pathogenic bacterial strains, viz. Staphylococcus aureus, Bacillus subtilis (Gram-positive), Escherichia coli, Pseudomonas aeruginosa (Gram-negative), and two fungal strains, viz . Aspergillus niger, Aspergillus flavus. The MICs shown by the complexes against these microbial strains have been compared with MICs shown by standard antibiotic ciprofloxacin and the antifungal drug amphotericin-B. [ABSTRACT FROM AUTHOR]

Abstract: A novel series of macrocyclic complexes of the type [M(C18H14N10S2)X]X2 where M=Cr(III), Fe(III) and Mn(III); X=Cl−, NO3 − and CH3COO− have been synthesized by [2+2] condensation of thiocarbohydrazide and isatin in the presence of trivalent metal salts in methanolic medium by template method. The complexes have been characterized with the help of elemental analyses, conductance measurements, magnetic measurements, electronic, NMR, IR and mass spectral studies. On the basis of these studies, a five coordinate square pyramidal geometry for all of these complexes has been proposed. These metal complexes were also tested for their in vitro antimicrobial activities against some bacterial strains viz. Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and some fungal strains Aspergillus niger, Aspergillus flavus (molds), Candida albicans, Saccharomyces cerevisiae (yeasts). [Copyright &y& Elsevier]

An eco-friendly one-pot five-component synthesis of novel 1,2,3-triazole-linked pentasubstituted 1,4-dihydropyridines under ultrasonic and microwave irradiation in polyethylene glycol (PEG) 400 is described. All newly synthesised compounds were evaluated for antibacterial activity, antifungal activity, antioxidant activity, and photophysical properties. Antimicrobial activity was evaluated against six microbial strains. All compounds exhibited antifungal activity against Aspergillus niger and Aspergillus flavus and moderate antibacterial activity against Gram positive bacteria (Staphylococcus aureus and Bacillus subtilis). Antioxidant activity was evaluated using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay. All compounds showed good to moderate antioxidant activity. Furthermore all new compounds showed strong fluorescence in solution. [ABSTRACT FROM AUTHOR]

Abstract: Two series of compounds namely, dihydroindeno and indeno [1,2-e] [1,2,4]triazolo [3,4-b] [1,3,4]thiadizines (9a–l &11a-l) were synthesized by cyclocondensation between α-bromoindanones (7a–b) or/and α,α-dibromoindanones (8a–b) and various 3-alkyl/aryl-4-amino-5-mercapto-1,2,4-s-triazoles (3a–f) in methanol with an aim to explore their effect on in vitro growth of microorganism causing microbial infection. In vitro antibacterial activity was performed against four strains namely, Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and antifungal activity against three fungal strains namely, Aspergillus niger, Aspergillus flavus, Penicillium species. Of all the compounds screened for activity some of the compounds were associated with considerably higher antibacterial and antifungal activity than commercial antibiotics. [Copyright &y& Elsevier]

Abstract: 1,3-Diaryl-4-formylpyrazoles 8 bearing benzenesulfonamide moiety at position-1 were synthesized as important intermediates following Vilsmeier–Haack strategy. Aldehyde moiety of 4-formylpyrazole was then converted into carboxylic acid 9, cyano 10 and carbothioamide 11 using established procedures. Out of these 4-functionalized pyrazoles, pyrazole-4-carboxylic acids 9 and carbothioamides 11 were evaluated for their in vitro antibacterial activity against four pathogenic bacterial strains namely, Staphylococcus aureus, Bacillus subtilis (Gram-positive), Escherichia coli, Pseudomonas aeruginosa (Gram-negative), and in vitro antifungal activity against two pathogenic fungal strains namely, Aspergillus niger and Aspergillus flavus. Three tested compounds, 9e, 11b and 11f exhibited moderate antibacterial activity against Gram-positive bacteria and 9g showed moderate antifungal activity against the tested fungi. However, none of the compounds showed any activity against Gram-negative bacteria. [Copyright &y& Elsevier]

Abstract: A series of novel 2,5-disubstituted 1,3,4-oxadiazoles 4 have been conveniently synthesized by oxidative cyclization of pyrazolylaldehyde N-acylhydrazones 3 promoted by iodobenzene diacetate under mild conditions (11 examples, up to 92% isolated yields). All the eleven compounds were tested in vitro for their antibacterial activity against Gram-positive bacteria namely, Staphylococcus aureus, Bacillus subtilis and two Gram-negative bacteria namely, Escherichia coli and Pseudomonas aeruginosa. All the synthesized compounds were also tested for their inhibitory action against two strains of fungus. [ABSTRACT FROM AUTHOR]

Abstract: Condensation reaction of 2,6-diaminopyridine with isatin in the presence of divalent metal ions results in the formation of the macrocyclic complexes of the type [M(C26H16N8)X2], where M=Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and X=Cl−, NO3 −, CH3COO−. The complexes have been characterized with the aid of elemental analyses, conductance measurements, electronic, NMR, infrared and EPR spectral studies. The lower values of molar conductance indicate them to be non-electrolytes. On the basis of these studies, a six coordinate distorted octahedral geometry in which four nitrogen atoms are suitably placed for coordination towards metal ion, has been proposed for all the complexes. The complexes were tested for their in vitro antibacterial activity. Some of the complexes showed good antibacterial activities against some selected bacterial strains. [Copyright &y& Elsevier]

All new compounds (V), (VII), and (IX) show good antimicrobial activities and strong fluorescence in methanol with large stoke shift. [ABSTRACT FROM AUTHOR]