ZrCl4-catalyzed C-O bond to C-N bond formation: synthesis of 1,2,3-triazoles and their biological evaluation

A simple and efficient protocol was developed for the synthesis of aryl azides directly from aryl carbinols using ZrCl4as a Lewis acid catalyst. The azides were converted to novel triazoles under click reaction conditions, which were evaluated for their antimicrobial activity against various strains

Impact of Carbon and Nitrogen Sources on L-Asparaginase Production by Isolated Bacillus circulans (MTCC 8574): Application of Saturated Plackett-Burman Design

The present work aimed to study the impact of different carbon and nitrogen sources on the effective production of L-asparaginase by isolated Bacillus circulans using Plackett-Burman design (PBD). Among carbon sources; lactose, galactose, starch, sucrose, maltose, arabinose and among nitrogen sources; proline, tryptone, sodium glutamate, corn steep liquor, beef extract, ammonium chloride, yeast extract at selected concentration produced a maximum of 105 and 164 U mL–1 L-asparaginase enzyme, respectively. Initial analysis of L-asparaginase data with different carbon and nitrogen sources as per PBD did not reveal standardized effects as well as ‘p’ and ‘t’ values. Regression coefficient and t-values were calculated by subjecting the experimental data to statistical analysis after pooling the least two nutrient components into error. Among selected 26 components, xylose, galactose, yeast extract and proline denoted least significance, while glucose, mannose, ammonium chloride and ammonium sulphate showed maximum significance on enzyme production. Saturated PBD can be effectively utilized for analysis of the data by pooling the least significant factors based on the effects on metabolite/product/enzyme production. Ammonium chloride and glucose were observed to be the most significant carbon and nitrogen sources, respectively in L-asparaginase production in this bacterial strain. The presented approach is highly useful in bioprocess optimization procedure where all selected parameters show little degree of freedom and subsequent significant factors

High Biomass Sorghum as a Potential Raw Material for Biohydrogen Production: A Preliminary Evaluation

Six high biomass sorghum lines (IS 22868, IS 27206, IS 15957, IS 16529, ICSV 93046 and CSH 22SS were evaluated for their potential as a substrate material for biohydrogen production by anaerobic fermentation using methanogens deactivated cow dung based mixed microbial consortia. The data revealed that all selected high biomass sorghum lines differed significantly for candidate biomass traits as well as for biomass composition. The high biomass lines, IS 27206 and IS 22868 recorded higher stalk and stover yield compared to others. Least biomass yield (stalk and stover) was noticed with ICSV 93046. The lignin content is low in IS 27206 and IS 15957. Highest biohydrogen yield was observed in IS 27206 followed by IS 22868 and ICSV 93046. The lignin content is negatively correlated with biohydrogen production

Fermentation of Pretreated High-Biomass Sorghum Hydrolysates to Biohydrogen by Mixed Consortia

In the present study, hydrolysate generated during pretreatment of high-biomass sorghum as a carbon source for biohydrogen production was investigated. The high-biomass sorghum bagasse (HBS) was pretreated using acid (H2SO4) and alkali (NaOH) at various concentrations (0.5–5 % w/v) for the residence time of 30 min at 121 °C, 15 lbs pressure at 10 % (w/v) solid loading. At the optimal acid load of 2 % (w/v) H2SO4 yielded 78.0 g COD/L of hydrolysate. The hydrolysate generated during this pretreatment was analyzed and noticed to contain glucose 10 g L−1, xylose 23 g L−1, arabinose 2.0 g L−1, HMF 1.9 g L−1, furfural 3.5 g−1, acetic acid 9.3 g L−1, formic acid 5.0 g L−1, and phenols 1.9 g L−1. The fermentation studies were conducted in dark conditions using all the hydrolysates by heat-treated mixed microbial consortia. Maximum H2 production rate (HPR), cumulative H2 production (CHP), and specific H2 yield (SHY) were measured. Maximum CHP (328 mL) and SHY (4.68 mol/kg CODr) were registered with acid treatment-resulted hydrolysate, and volatile fatty acid analysis indicated higher acetic acid concentration (1.6 g L−1) showing acidogenic microenvironment directing fermentation toward acetate pathway. The present study assumes importance in safe disposal and simultaneous production of value-added byproducts during lignocellulosic biorefinery. Fermentation of Pretreated High-Biomass Sorghum Hydrolysates to Biohydrogen by Mixed Consortia

Sweet sorghum juice as an alternate substrate for fermentative hydrogen production: Evaluation of influencing parameters using DOE statistical approach

Biohydrogen production using agro-industrial by-products has considerable practical importance. Sweet sorghum is an ideal feedstock for biofuel production in the semi-arid and arid climatic regions. In the present investigation, the juice of SSV 74, a sweet sorghum variety, was examined as a novel substrate for biohydrogen production. The impact of medium pH, substrate, inoculum level and incubation temperature were analyzed at individual and interactive levels on biohydrogen production. Substrate level concentration and pH of the fermentation medium played a critical role on overall biohydrogen production at individual level, and indicated >90 % influence on product yield. On the other hand at interactive level; pH of the fermentation medium, inoculum and substrate concentrations revealed maximum severity index of 78 % (43 % for medium pH vs inoculum concentration and 35 % for inoculum vs substrate concentration). Overall, biohydrogen production yield was enhanced from 283 to 546 mL/3.25 g glucose equivalents of juice upon statistical optimization leading to a >190 % of H2 yield. Along with the H2 production, various acid intermediates were produced with acetate in maximum concentration indicating the occurence of acetogenic fermentatio

A convenient synthesis and biological activities of N-(pyridin-3-ylmethylene) benzohydrazides by the condensation of nicotinaldehydes with benzohydrazides

Series of N'-(pyridine-3-ylmethylene)benzohydrazides 3a-y have been prepared by the condensation of nicotinaldehydes 1a-e with benzohydrazides 2a-e in the presence of glacial AcOH in ethanol at room temperature. Total twenty five compounds have been prepared and confirmed based on spectral data. The compounds have been evaluated for anti-microbial, free radical scavenging (DPPH, ABTS.+) and α-glucosidase inhibitory activities. Compound 3h has shown potent anti-fungal activity. Compounds 3f-g and 3j have shown potent ABTS.+ free radical scavenging activity. Compound 3d has shown potent anti-hyperglycemic activity.

Quantification of Dhurrin in Different Types of Sorghum Forages by Near-Infrared Reflectance Spectroscopy

Hydrogen cyanide (HCN) is a toxic chemical that can potentially cause mild to severe reactions in animals upon feeding forage sorghum. Developing technologies to monitor the level of HCN in the growing crop could prevent livestock poisoning. In this study ncar-infrared spectroscopy (NIRS) calibration to estimate HCN in forage sorghum is developed. The full spectral NIRS range (1100-2498 nm) was used as well as specific spectral ranges within the full spectral range, i.e. , visible (400-750 nm), short wave (800-1100 nm) and near - infrared (NIR) (1100-2498 nm). Using the full spectrum approach and the modified partial least-squares (MPLS), the calibration produced a coefficient of determination (R2) = 0.869 and standard error of cross-validation (SFCV) = 97.53%, while the validation set had a R2=0.624 with a low standard error of prediction (SEP= 205.801 %)

A convenient synthesis and biological activities of N-(pyridin-3-ylmethylene) benzohydrazides by the condensation of nicotinaldehydes with benzohydrazides

117-126Series of N'-(pyridine-3-ylmethylene)benzohydrazides 3a-y have been prepared by the condensation of nicotinaldehydes 1a-e with benzohydrazides 2a-e in the presence of glacial AcOH in ethanol at room temperature. Total twenty five compounds have been prepared and confirmed based on spectral data. The compounds have been evaluated for anti-microbial, free radical scavenging (DPPH, ABTS.+) and α-glucosidase inhibitory activities. Compound 3h has shown potent anti-fungal activity. Compounds 3f-g and 3j have shown potent ABTS.+ free radical scavenging activity. Compound 3d has shown potent anti-hyperglycemic activity

Xylanase Production by Isolated Fungal Strain, Aspergillus fumigatus RSP-8 (MTCC 12039): Impact of Agro-industrial Material as Substrate

In the present investigation, the imperative role of agro-industrial biomass for improved xylanase production was evaluated using isolated fungal strain. This isolate was identified as Aspergillus fumigatus RSP-8 (MTCC 12039) based on morphological and 18S rRNA ribotyping and the organism was deposited in MTCC, IMTECH Chandigarh with accession number 12039. The isolated fungal strain is mesophilic in nature and produced maximum xylanase at 30 °C, at pH 7 and agitation speed of 150 rpm. Xylanase complex production titers differed with the nature and complexity of carbon source and other physiological growth parameters including aeration, growth temperature, physiological medium pH, initial inoculum levels, etc. Highest xylanase titers (73 U/mL) noticed with hemicellulose isolated from sorghum straw and least with ground nut cake as carbon source among tested agro materials such as rice bran, green gram husk, sorghum straw, groundnut cake and wheat bran. A variation of three fold enzyme titers was observed with different tested carbon sources. Supplementation of glucose as carbon source did not produce any xylanase with this fungal strain revealing the xylanase in this isolate is induced by the carbon source. Variation of hemicellulose concentration as carbon source during the fermentation altered the production xylanase titers. The study suggested that, in xylanase production by A. fumigatus RSP-8, one of the major limiting factors is substrate chemical complexity

Condensation of nicotinaldehydes with acetophenones and NH4OAc: A convenient synthesis and biological activities of 2',6'-diphenyl-3,4'-bipyridines

2',6'-Diphenyl-3,4'-bipyridines 3a-t have been achieved by the three-component, one-pot reaction of nicotinaldehydes 1a-b, acetophenones 2a-j and anhydrous ammonium acetate under solvent free conditions at 120°C. All the prepared compounds 3a-t have been screened for anti-microbial, free-radical scavenging and α-glucosidase inhibitory activities. Compounds 3m-r have shown anti-bacterial activity and compounds 3m-n identified as anti-fungal agents. Compounds 3d, 3h, 3m and 3r-s have shown α-glucosidase inhibitory activity