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Articles
by
C. Karthikeyan |
Total Records (
5 ) for
C. Karthikeyan |
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Ashutosh Jamloki
,
C. Karthikeyan
,
S.K. Sharma
,
N.S. Hari Narayana Moorthy
and
P. Trivedi
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A quantitative structure-activity relationship study on 6-aryl-pyrazolo (3,4-b) pyridines was performed to gain structural insight into the binding mode of the molecules to the glycogen synthase kinase -3α, an enzyme phosphorylate and inhibit Glycogen Synthase (GS) which is the rate limiting enzyme in the glycogen biosynthesis. The molecular modeling studies were performed using CS Chem. Office 2001 molecular modeling software version 6.0. Allinger`s MM2 force field by fixing Root Mean Square Gradient (RMS) to 0.1 Kcal mol-1 and semiemperical AM1 Hamiltonian method (MOPAC module) were used to minimize the energy and calculate descriptors. The thermodynamic and steric features of 6-aryl-pyrazolo (3,4-b) pyridines are highly correlated with GSK-3α inhibitory activity. The results of the study suggests that introduction of bulky groups at C-5 position of the pyrazolopyridine ring will increase the GSK-3α inhibitory potency as it may involve in hydrophobic interaction with the ATP binding site of the enzyme. The results of the study reveal that the conformational rigidity and orientation of molecule play significant role in the GSK-3α inhibitory activity. Additionally, electronic interactions between molecule and enzyme were found to be crucial for GSK-3α inhibitory activity. |
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Garvita Chaudhary
,
C. Karthikeyan
,
N.S. Hari Narayana Moorthy
and
Piyush Trivedi
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Quantitative Structure Activity Relationship (QSAR)
studies were performed on some tubulin-binding agents. The compounds in
the selected series were characterized by topological and Approximate
Surface Area descriptors calculated using QuaSAR module of Molecular Operating
Environment (MOE). Significant equations were derived from regression
analysis shows significance of different descriptors contributing towards
the cytotoxic activity. The results of the study show that cytotoxic activity
of diarylsulphonylurea can be successfully explained in terms of topology
of the molecule. VSA_don contribution towards the activity indicates molecules
capable of hydrogen bonding will be beneficial for tubulin polymerization
inhibitory activity. Another descriptor contributing beneficially to the
cytotoxic action of diarylsulphonylurea is SMR_VSA5. SMR deals with polarizibility;
hence increasing polarizibility will increase cytotoxic activity. Negative
contribution of a_nN descriptor to the biological activity, signifies
that the introduction of nitrogen should be kept minimum while designing
new cytotoxic diarylsulphonylurea compounds. The negative coefficient
of the descriptor Wiener Path suggests that increased branching in the
side chain and resultant decrease in its flexibility is conducive for
cytotoxic activity. |
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C.M. Lucksha
,
D. Agarwal
,
N.S.H.N. Moorthy
,
C. Karthikeyan
and
P. Trivedi
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Synthesis and biological evaluation of amino acid conjugates of cinmetacin was carried out to improve some pharmacokinetic properties and to minimize some undesirable side effects (especially ulcerogenic effect). Dissolution studies and hydrolysis studies on simulated intestinal fluid (pH 7.4) follow the first order kinetics. The quantitative structure property relationship studies reveals that rate of hydrolysis of the compounds is inversely related to partition coefficient values. The study of acute and chronic anti-inflammatory and ulcerogenic activity gave statistically significant results and it concluded that the compounds minimize the gastric side effects of cinmetacin remarkably. |
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C. Karthikeyan
,
S. Siva kumar
,
P. Chandrasekar
,
A. Heber
,
S.J.H. Robert
and
N.S.H.N. Moorthy
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Antisecretory, gastric transit time and wound healing activity of various extract of the shade-dried powder of Asclepias daemia leaves was studied in albino rat and mice respectively. Concentration of gastric hydrogen ions was determined for antisecretory activity by titration with 0.01 N sodium hydroxide using Tofers reagent as an indicator. The gastric transit activity was determined by using charcoal meal. The results showed that chloroform and aqueous extract produced significant action on antisecretory, gastric transit time and wound healing activities, while petroleum ether extract have no remarkable activity. Aqueous extract showed highly significant (p<0.01) antisecretory and gastric transit activities. |
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