ABSTRACT
A Simple, rapid, specific, accurate, economical and precise UV spectrophotometric and RP-HPLC methods (inaccordance with ICH guidelines) were developed and validated for determination of Nortriptyline hydrochlorideand Pregabalin in tablet dosage form. The first method was based on Q - absorbance ratio, and absorbances ofboth drugs were determined at 239 nm (λmax of Nortriptyline Hydrochloride) and 235 nm (Iso-absorptive Point)when dissolved in methanol. It is found that Pregabalin does not have chromophoric group. To be UV-sensitive,it was compulsory to introduce chromophoric group in Pregabalin structure and make it UV-sensitive. This wasachieved by converting the primary amine group of Pregabalin through reaction with benzoyl chloride to formbenzoylated derivative of Pregabalin. Benzoylated Pregabalin was determined at 225 nm using UV-visiblespectrophotometer. The second method was based on RP-HPLC. The chromatographic separation was performedon an Inertsil ODS C18 column (250 x 4.6mmx 5 μm) with a mobile phase of 0.56 %w/v Sodium hexane sulphonicacid dissolved in water acetonitrile (50:50 %v/v, pH 4.5 adjusted with Glacial Acetic Acid) at flow rate of 1.0mL/min with DAD detection wavelength at 210 nm. Retention times of Nortriptyline Hydrochloride andPregabalin were 7.3894 min and 4.0506 min, respectively. Beer-Lambert’s law obeyed the concentration rangeof 2-12 μg/mL for Nortriptyline Hydrochloride and 10-60 μg/mL for Pregabalin. The results indicated that bothspectrophotometric and RP-HPLC methods were linear, accurate, precise and robust with RSD values less than0.2% and % recovery was within the standard limits (99 - 102%).
ABSTRACT
We investigated the occurrence of Factor XI (FXI) deficiency syndrome in the following Indian dairy animals: Bos taurus Holstein-Friesian and Jersey cattle, Bos indicus Indian cattle breeds, B. taurus x B. indicus crossbreds and the river buffalo Bubalus bubalis. Factor XI deficiency is an autosomal recessive bleeding disorder known to affect Holstein cattle worldwide. A total of 1001 dairy animals, mainly bulls, were genotyped to detect the mutation within exon 12 of the gene encoding for factor XI. Two Holstein bulls were detected as heterozygous (carrier) for FXI deficiency, giving a carrier frequency of 0.6 percent in Indian Holstein cattle. None of the other cattle or buffalo breeds was found to be a carrier for FXI. Sequence comparison between normal and heterozygous animals revealed that there is a 77 base pair insertion fragment (AT (A)29 TAAAG (A)27 GAATTATTAATTCT) within exon 12 of the FXI gene. Both sequences were submitted to the National Center for Biotechnology Information (NCBI) GenBank and assigned the accession numbers DQ438908 for normal Holstein Friesian animals and DQ438909 for heterozygous Holstein Friesian animals.
ABSTRACT
The present study deals with the isolation and characterization of the moderately halophilic-alkaliphilic bacteria from a saline habitat in western India. Eight different bacterial strains were isolated using enrichment techniques at 20 percent (w/v) NaCl and pH 10. The isolates exhibited diversity towards gram's reaction, colony and cell morphology. They were able to grow and produce alkaline protease over a broad range of NaCl, 5-20 percent (w/v) and pH, 8-10. None of the isolates could grow at pH 7, and one could not grow even at pH 8. Crude and partially purified proteases from strain S5 were subjected to characterization with reference to pH, salt stability and protein folding. Optimum protease activity and stability was recorded at 10 percent salt and pH 9-9.5. Denaturation kinetics of S5 alkaline protease along with a reference protease was studied at 8M urea followed by renaturation. The S5 alkaline protease could be partially renatured up to 32 percent of the original activity. Despite of the fact that all the 8 isolates were from the same site, they displayed significant diversity with respect to their salt requirement for growth and enzyme secretion. While the effect of pH was less demarcated on growth, the protease production was significantly affected. Isolate S5 produced substantial amount of halotolerant and alkaline protease. The activity and stability of the alkaline protease in a broader range of pH and salt would definitely make this enzyme an important candidate for various industrial applications.
O presente estudo relata o isolamento e caracterização de bactérias moderadamente halofilicas e alcalífilicas de um habitat salino no oeste da índia. Oito cepas diferentes de bactérias foram isoladas empregando técnicas de enriquecimento em NaCl a 20 por cento (p/v) e pH 10. As cepas apresentaram diversidade em relação à coloração de Gram e à morfologia das colônias e células. As cepas foram capazes de multiplicar e produzir protease alcalina em uma ampla faixa de concentração de NaCl (5 a 20 por cento) e pH (8 a 10). Nenhuma das cepas foi capaz de se multiplicar em pH 7, e uma não se multiplicou nem em pH 8.0. Proteases naturais e parcialmente purificadas da cepa S5 foram submetidas à caracterização com relação ao pH, estabilidade salina, e estrutura protéica. Atividade e estabilidade ótimas da protease foram obtidas com 10 por cento de sal e pH 9-9,5. A cinética de denaturação da protease de S5, juntamente com uma protease de referencia, foi avaliada com uréia 8M seguida de renaturação. A protease alcalina de S5 foi renaturada a 32 por cento da atividade original. Apesar de provenientes do mesmo local, as oito cepas mostraram grande diversidade em relação à exigência de sal para multiplicação e secreção enzimática. Enquanto o efeito do pH na multiplicação foi menos marcante, o efeito na produção de protease foi significativamente afetada. A cepa S5 produziu uma quantidade substancial de protease alcalina e halotolerante. A atividade e estabilidade da protease alcalina em uma faixa mais ampla de pH e sal tornam essa enzima uma importante candidata para diversas aplicações industriais.