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381.
Sathyanarayana N. Gummadi Swati Sucharita Dash Santhosh Devarai 《Journal of industrial microbiology & biotechnology》2009,36(5):713-720
The effect of pH, aeration rate, and agitation rate on specific productivity of caffeine demethylase from Pseudomonas sp. was studied in a bioreactor. Maximum specific productivity of caffeine demethylase of 2,214 U g cell dry weight−1 h−1 was obtained at 0.27 vvm, 700 rpm, and pH 7.0. Under these conditions, volumetric oxygen transfer coefficient was 74.2 h−1, indicating that caffeine demethylase production by Pseudomonas sp. was highly oxygen-dependent. Different metabolite formation at different agitation and aeration rates can be used as
a strategy for recovery of pharmaceutically important metabolites from caffeine by manipulation of conditions in a bacterial
culture. This is the first report on production of high levels of caffeine demethylase in bioreactors. 相似文献
382.
V. Thirunavukkarasu A. T. Anitha Nandhini C. V. Anuradha 《Experimental diabetes research》2004,5(3):195-200
This study investigated the effect of administration of
α-lipoic acid (LA) on lipid metabolism in high fructose–fed insulin-resistant rats. High-fructose feeding (60 g/100 g
diet) to normal rats resulted in a significant increase in
the concentrations of cholesterol, triglycerides (TGs), free
fatty acids (FFAs), and phospholipids in plasma, liver, kidney,
and skeletal muscle. Reduced activities of lipoprotein
lipase (LPL) and lecithin cholesterol acyl transferase
(LCAT) and increased activity of the lipogenic enzyme
hydroxymethylglutaryl–coenzyme A (HMG-CoA) reductase
were observed in plasma and liver. High-density
lipoprotein cholesterol (HDL-C) was significantly lowered
and very low-density lipoprotein cholesterol (VLDL-C) and
low-density lipoprotein cholesterol (LDL-C) were significantly
elevated. Treatment with LA (35 mg/kg body weight
intraperitoneal) reduced the effects of fructose. The rats
showed near-normal levels of lipid components on plasma
and tissues. Activities of key enzymes of lipid metabolism
were also restored to normal values. Cholesterol distribution
in the plasma lipoproteins was normalized, resulting in
a favorable lipid profile. This study demonstrates that LA
can alter lipid metabolism in fructose-fed insulin-resistant
rats and may have implications in the treatment of insulin
resistance. 相似文献
383.
384.
It has been shown that interaction of dissolved oxygen with DNA in an aqueous solution causes oscillations in the DNA structure and leads to the formation of a loose DNA-oxygen complex. These results have been compared with those obtained with solution of DNA in high salt concentration. 相似文献
385.
386.
Molecular electrostatic potential(MEP) maps of azido thymidine (AZT), some of its analogs and derivatives and certain other 2′,3′-dideoxy nucleosides having different anti-HIV activities have been studied. The optimised hybridization displacement charges (HDC) combined with MNDO Löwdin charges, continuosly distributed in three dimension spherically symmetrically as a Slater cloud at each site were used to compute the MEP maps. The negative MEP region near the O5′ sites of these molecules appears to be of primary importance from the point of view of their anti-HIV activity. The roles of the azido group in AZT and fluorine atoms substituted at different positions in the sugar moiety have been evaluated. The azido group in AZT behaves as a strongly electronegative group. 相似文献
387.
Selvan Nehru John Abraham Anitha Priya Sekar Hariharan Rajadurai Vijay Solomon Selvakumar Veeralakshmi 《Journal of biomolecular structure & dynamics》2020,38(7):2057-2067
AbstractFor efficient designing of metallodrugs, it is imperative to analyse the binding affinity of those drugs with drug-carrying serum albumins to comprehend their structure–activity correlation for biomedical applications. Here, cobalt(II) and cobalt(III) complexes comprising three phendione ligands, [Co(phendione)3]Cl2 (1) and [Co(phendione)3]Cl3 (2), where, phendione = 1,10-phenanthroline-5,6-dione, has been chosen to contrast the impact of their hydrophobicity and ionicity on binding with bovine serum albumin (BSA) through spectrophotometric titrations. The attained hydrophobicity values using octanol/water partition coefficient method manifested that complex 1 is more hydrophobic than complex 2, which could be attributed to lesser charge on its coordination sphere. The interaction of complexes 1 and 2 with BSA using steady state fluorescence studies revealed that these complexes quench the intrinsic fluorescence of BSA through static mechanism, and the extent of quenching and binding parameters are higher for complex 2. Further thermodynamics of BSA-binding studies revealed that complexes 1 and 2 interact with BSA through hydrophobic and hydrogen bonding/van der Waals interactions, respectively. Further, UV–visible absorption, circular dichroism and synchronous fluorescence studies confirmed the occurrence of conformational and microenvironmental changes in BSA upon binding with complexes 1 and 2. Molecular docking studies have also shown that complex 2 has a higher binding affinity towards BSA as compared to complex 1. This sort of modification of ionicity and hydrophobicity of metal complexes for getting desirable binding mode/strength with drug transporting serum albumins will be a promising pathway for designing active and new kind of metallodrugs for various biomedical applications.Communicated by Ramaswamy H. Sarma 相似文献
388.
V. Thirunavukkarasu A. T. Anitha Nandhini C. V. Anuradha 《Experimental diabetes research》2004,5(4):237-244
Nonenzymatic glycation of proteins, leading to chemical
modification and cross-linking are of importance in the
pathology of diabetic complications.We studied the effect of
α-lipoic acid (LA) on the content and characteristics of the
protein collagen from skin of high-fructose fed rats. The
rats were divided into 4 groups of 6 each. Two groups of
rats were fed with a high fructose diet (60 g/100 g diet) and
administered either LA (35 mg/kg b.w., i.p) (FRU+LA) or
0.2 ml vehicle (saline) (FRU) for 45 days. The other 2 groups
were fed with control diet containing starch (60 g/100 g
diet) and administered either saline (CON) or lipoic acid
(CON+LA). The rats were maintained for 45 days and then
sacrificed. Plasma glucose, insulin, fructosamine, protein
glycation, and blood glycated hemoglobin (HbA1C) were
measured. Collagen was isolated from skin and the physicochemical
properties of collagen were studied. Fructose administration
caused accumulation of collagen in skin. Extensive
cross-linking was evidenced by enhanced glycation
and AGE-linked fluorescence. Increased peroxidation and
changes in physicochemical properties such as shrinkage
temperature, aldehyde content, solubililty pattern, susceptibility
to denaturing agents were observed in fructose-fed
rats. SDS gel pattern of collagen from these rats showed
elevated β component of type I collagen. These changes
were alleviated by the simultaneous administration of LA.
Administration of LA to fructose-fed rats had a positive
influence on both quantitative and qualitative properties of collagen. The results suggest a mechanism for the ability
of LA to delay diabetic complications. 相似文献