Thiazolotriazoles As Anti-infectives: Design, Synthesis, Biological Evaluation and In Silico Studies.

The rational design of novel thiazolo[2,3-c][1,2,4]triazole derivatives was carried out based on previously identified antitubercular hit molecule H127 for discovering potent compounds showing antimicrobial activity. The designed compounds were screened for their binding efficacies against the antibacterial drug target enoyl-[acyl-carrier-protein] reductase, followed by prediction of drug-likeness and ADME properties. The designed analogues were chemically synthesized, characterized by spectroscopic techniques, followed by evaluation of antimicrobial activity against bacterial and fungal strains, as well as antitubercular activity against M. tuberculosis and M. bovis strains. Among the synthesized compounds, five compounds, 10, 11, 35, 37 and 38, revealed antimicrobial activity, albeit with differential potency against various microbial strains. Compounds 10 and 37 were the most active against S. mutans (MIC: 8 µg/mL), while compounds 11 and 37 showed the highest activity against B. subtillis (MIC: 16 µg/mL), whereas compounds 10, 11 and 37 displayed activities against E. coli (MIC: 16 µg/mL). Meanwhile, compounds 10 and 35 depicted activities against S. typhi (MIC: 16 µg/mL) and compound 10 showed antifungal activity against C. albicans (MIC: 32 µg/mL). The current study has identified two broad-spectrum antibacterial hit compounds (10 and 37). Further structural investigation on these molecules is underway to enhance their potency.

Lipase mediated new chemo-enzymatic synthesis of (RS)-, (R)-, and (S)-bunolol.

The ß-adrenergic receptor blocking agents are an important class of drug molecules. The present study reports a new chemo and chemo-enzymatic synthetic process for (RS)-, (R)-, and (S)-bunolol, one of the potent ß-adrenergic receptor blocker. In chemo-enzymatic process, CAL L4777 lipase was employed for enantioselective kinetic resolution to synthesize the enantiopure (R)-alcohol and (S)-ester from the corresponding racemic alcohol. Thereafter, the corresponding (R)-alcohol and deacylated (S)-ester were treated with tert-butylamine to produce (S)- and (R)-bunolol, respectively. In chemical approach, epichlorohydrin (RS-, R-, and S-) was used as a starting material via respective (RS)-, (S)-, and (R)-glycidyl ether as intermediates for synthesis of enantiomeric (RS)-, (R)-, and (S)-bunolol. In comparison between two approaches, it was found that the chemo-enzymatic process was more effective and resulted in enantiomeric excess of 98% with 35% yield.

Mutanase Enzyme from Paracoccus mutanolyticus RSP02: Characterization and Application as a Biocontrol Agent.

Mutanases are enzymes that have the ability to cleave α-1,3 linkages in glucan polymer. In the present investigation, mutanase enzyme purified from the culture filtrate of Paracoccus mutanolyticus was evaluated for Streptococcal biofilm degradation and antimicrobial activity against pathogenic fungi along with enzyme kinetics, activation energies, pH and thermal stability. Biochemical and molecular characterization depicted that the enzyme showed optimum activity at pH 5.5 and at 50 °C. It displayed Michaelis-Menten behaviour with a Km of 1.263 ± 0.03 (mg/ml), Vmax of 2.712 ± 0.15 U/mg protein. Thermal stability studies denoted that it required 55.46 and 135.43 kJ mol-1 of energy for activation and deactivation in the temperature range of 30-50 °C and 50-70 °C respectively. Mutanase activity was enhanced ~ 50 and 75% by Fe2+ and EDTA, respectively, while presence of Hg2+ and Mn2+ inhibit > 90% of its activity. This enzyme has a molecular mass of 138 kDa and showed monomeric nature by Zymography. Scanning electron microscopy analysis of mutanase treated Streptococcal cells revealed cleavage of linkages among the cells and complete separation of cells, indicating its potential in dentistry as an anticaries agent in the prophylaxis and therapy of dental caries. In addition, antifungal activity of mutanase against Colletotrichum capsici MTCC 10147 and Cladosporium cladosporioide MTCC 7371 revealed that the enzyme has potential towards biological control of phytopathogens which could be used as an alternative bio-control agent against chemical pesticides in the future.

Complete Genome Sequence of α-1,3-Glucanase-Producing Strain Paracoccus mutanolyticus RSP-02.

A mutanase (α-1,3 glucanase)-producing bacterial strain of Paracoccus mutanolyticus was isolated from soil samples rich in cellulosic waste. Here, we report the whole-genome sequencing and annotation of P. mutanolyticus, which has a genome size of around 3.5 Mb and the potential to degrade water-insoluble α-1,3 glucans with an overall G+C content of 67.4%.

Synthesis, pharmacological activities and molecular docking studies of pyrazolyltriazoles as anti-bacterial and anti-inflammatory agents.

A series of novel pyrazolyl alcohols (5a-h), pyrazolyl azides (6a-h), and pyrazolyltriazoles (8a-h, 10a-p and 12a-l) were prepared and evaluated for their bioactivity (anti-bacterial and anti-inflammatory) profile. The compound 5c displayed the potent anti-bacterial activity against Micrococcus luteus (MIC 3.9 and MBC 7.81µg/mL). In vitro anti-inflammatory activity data denoted that compound 8b is effective among the tested compounds against IL-6 (IC50 6.23µM). Docking analysis of compounds 5f, 8a-b, 8e-f and 8h displayed high binding energies for the compounds 8a-b and 8h towards TNF-α dimer (2AZ5 protein) and IL-6 (1ALU protein). In vivo anti-inflammatory activity of compounds 8b and 8h with respect to LPS induced mice model indicated that compound 8h showed significant reduction in TNF-α.

Synthesis, characterization and antimicrobial activity of novel Schiff base tethered boronate esters of 1,2-O-isopropylidene-α-d-xylofuranose.

A series of twenty one Schiff bases based on boronate ester of 1,2-O-isopropylidene-α-d-xylofuranose scaffold were designed and synthesized by condensation of formyl or amino phenyl boronate esters with substituted anilines or 2-hydroxybenzaldehydes, respectively. All the imines are remarkably stable crystalline solids and were obtained in good yields. All the products were fully characterized by FT-IR, multinuclear NMR ((1)H, (13)C and (11)B) spectroscopy, and elemental analysis. Furthermore, the molecular structures of two of the Schiff bases were established by single crystal X-ray diffraction analysis. All the compounds have been screened for in vitro antimicrobial activity against various Gram-positive and Gram-negative bacterial and fungal strains. They exhibited moderate to good inhibitory activity against most of the tested organisms in comparison with standard drugs.

High yield expression of novel glutaminase free L-asparaginase II of Pectobacterium carotovorum MTCC 1428 in Bacillus subtilis WB800N.

Gene encoding glutaminase-free L-asparaginase II (ans B2) from Pectobacterium carotovorum MTCC 1428 was cloned into pHT43, transformed in Bacillus subtilis WB800N and optimised the expression levels of recombinant enzyme. A three-fold higher enzyme production was observed with an efficient transformant as compared to native strain. Enzyme localization studies revealed that >90% of recombinant enzyme is secreted extracellularly, a little fraction is attached to the membrane (>6%) and localised intracellularly (3%). The expression of recombinant L-asparaginase II was confirmed by SDS-PAGE, IMAC (Immobilised metal ion affinity chromatography) purification followed by Western blotting. Process parameter optimization with OFAT (one factor at a time) revealed that rpm (120), temperature (37 °C), Isopropyl ß-D-1-thiogalactopyranoside (IPTG) concentration (1 mM) and time of induction (0.8 OD600nm) plays a vital role where a maximum of 55 IU/ml was achieved. Further, consecutive induction by IPTG improved the enzyme production up to 105 IU/ml with a specific activity of 101 IU/mg of protein. Molecular modelling analysis depicted that amino acids, GLY60, GLY119 and ALA252 in the active site are responsible for the glutaminase free L-asparaginase II activity. This is the first report on enhanced expression of recombinant glutaminase-free L-asparaginase II by intermediate addition of IPTG.

Production and Characterization of Protein Encapsulated Silver Nanoparticles by Marine Isolate Streptomyces parvulus SSNP11.

Production of protein encapsulated silver nanoparticles (AgNPs) assisted by marine actinomycetes strain has been investigated. The selective isolate was identified as Streptomyces parvulus SSNP11 based on chemotaxonomic and 16S rRNA analysis. Maximum AgNPs production was observed within 24 h incubation time. The produced AgNPs are spherical in shape with monodispersive and crystalline in nature. The particle size distribution ranges from 1.66 to 11.68 nm with a mean size of 2.1 nm. The biosynthesized AgNPs revealed stretching vibrations of primary and secondary amines along with C-H and C-N, suggesting that metabolically produced proteins are involved in size regulation of reduced AgNPs. These particles possess an average negative zeta potential value of 81.5 mV with an electrophoretic mobility of 0.000628 cm(2)/Vs. The biosynthesized nanoparticles revealed antimicrobial property against gram negative as well as gram positive bacterial strains.

Intensification of Fructosyltransferases and Fructo-Oligosaccharides Production in Solid State Fermentation by Aspergillus awamori GHRTS.

The present work was aimed to investigate the impact of the solid substrates mixture on Fructosyltransferases (FTase) and Fructo-oligosaccharides (FOS) production. An augmented simplex lattice design was used to optimize a three component mixture for FTase production. Among selected substrates corn cobs has highest impact on FTase production followed by wheat bran and rice bran. All two substrates and three substrate combinations showed the highest enzyme production than their individual levels. Among the tested various models quadratic model was found to be the best suitable model to explain mixture design. Corncobs, wheat bran and rice bran in a ratio of approximately 45:29:26 is best suitable for the FTase production by isolated Aspergillus awamori GHRTS. This study signifies mixture design could be effective utilize for selection of best combination of multi substrate for improved production of high value products under solid state fermentation.

Characterization of silver nanoparticles synthesized by using marine isolate Streptomyces albidoflavus.

Silver nanoparticles production by the green chemistry approach was investigated using an isolated marine actinomycetes strain. The isolated strain was identified as Streptomyces albidoflavus based on chemotaxonomic and ribotyping properties. The strain revealed production of silver nanoparticles both extracellular and intracellularly. Surface Plasmon Resonance analysis with the function of time revealed that particle synthesis by this strain is reaction time dependent. The produced particles were spherical shaped and monodispersive in nature and showed a single surface plasmon resonance peak at 410 nm. Size distribution histograms indicated production of 10-40- nm-size nanoparticles with a mean size of 14.5 nm. FT-IR spectra of nanopartilces showed N-H, C-H, and C-N stretching vibrations, denoting the presence of amino acid/ peptide compounds on the surface of silver nanoparticles produced by S. albidoflavus. Synthesized nanoparticles revealed a mean negative zeta potential and electrophoretic mobility of -8.5 mV and -0.000066 cm2/Vs, respectively. The nanoparticles produced were proteinaceous compounds as capping agents with -8.5 mV zeta potential and revealed antimicrobial activity against both Gram-negative and -positive bacterial strains. Owing to their small size, these particles have greater impact on industrial application spectra.

Nickel-impregnated silica nanoparticle synthesis and their evaluation for biocatalyst immobilization.

In the present investigation, impact of nickel-impregnated silica paramagnetic particles (NSP) as biocatalyst immobilization matrices was investigated. These nanoparticles were synthesized by sol-gel route using a nonionic surfactant block co polymer [poly (ethylene glycol)-block-poly-(propylene glycol)-block-poly (ethylene glycol)]. Diastase enzyme was immobilized on these particles (enzyme-impregnated NSP) as model enzyme and characterized using Fourier-transform infrared spectroscopy and X-ray crystallography. Analysis of enzyme-binding nature with these nanoparticles at different physiological conditions revealed that binding pattern and activity profile varied with the pH of the reaction mixture. The immobilized enzyme was further characterized for its biocatalytic activity with respect to kinetic properties such as Km and Vmax and compared with free enzyme. Paramagnetic nanoparticle-immobilized enzyme showed more affinity for substrate compared to free one. The nature of silica and nickel varied from amorphous to crystalline nature and vice versa upon immobilization of enzyme. To the best of our knowledge, this is the first report of its kind for change of nature from one form to other under normal temperatures upon diastase interaction with NSP.

Strain improvement of Candida tropicalis for the production of xylitol: biochemical and physiological characterization of wild-type and mutant strain CT-OMV5.

Candida tropicalis was treated with ultraviolet (UV) rays, and the mutants obtained were screened for xylitol production. One of the mutants, the UV1 produced 0.81 g of xylitol per gram of xylose. This was further mutated with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), and the mutants obtained were screened for xylitol production. One of the mutants (CT-OMV5) produced 0.85 g/g of xylitol from xylose. Xylitol production improved to 0.87 g/g of xylose with this strain when the production medium was supplemented with urea. The CT-OMV5 mutant strain differs by 12 tests when compared to the wild-type Candida tropicalis strain. The XR activity was higher in mutant CT-OMV5. The distinct difference between the mutant and wild-type strain is the presence of numerous chlamydospores in the mutant. In this investigation, we have demonstrated that mutagenesis was successful in generating a superior xylitol-producing strain, CT-OMV5, and uncovered distinctive biochemical and physiological characteristics of the wild-type and mutant strain, CT-OMV5.