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Junbiao Chang - One of the best experts on this subject based on the ideXlab platform.
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synthesis of 2 amino 1 3 4 oxadiazoles and 2 amino 1 3 4 thiadiazoles via sequential condensation and i2 mediated oxidative c o c s bond formation
Journal of Organic Chemistry, 2015Co-Authors: Jinfeng Kang, Xianhai Tian, Lina Song, Jie Wu, Wenquan Yu, Junbiao ChangAbstract:2-Amino-substituted 1,3,4-oxadiazoles and 1,3,4-thiadiazoles were synthesized via condensation of Semicarbazide/thioSemicarbazide and the corresponding aldehydes followed by I2-mediated oxidative C–O/C–S bond formation. This transition-metal-free sequential synthesis process is compatible with aromatic, aliphatic, and cinnamic aldehydes, providing facile access to a variety of diazole derivatives bearing a 2-amino substituent in an efficient and scalable fashion.
Toshio Obata - One of the best experts on this subject based on the ideXlab platform.
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Semicarbazide-Sensitive Amine Oxidase (SSAO) in the Brain
Neurochemical Research, 2002Co-Authors: Toshio ObataAbstract:Semicarbazide-sensitive amine oxidase (SSAO) is widely distributed in almost tissues. However, its presence in brain microvessels is still controversial. The affinity of SSAO towards benzylamine (Bz) is considerably higher than that of monoamine oxidase (MAO). SSAO plays a role in the toxicity of several environmental and endogenous amines. SSAO-mediated production of toxic aldehydes has been proposed to be related to pathophysiological conditions. The most potent of inhibition of SSAO in monkey brain was observed by tricyclic antidepressant drug imipramine, as compared to tetracyclic drug maprotiline or non-cyclic drug nomifensine. An endogenous SSAO modulator in rat brain cytosol after immobilization stress (IMMO) was found and that this inhibitor could be induced by IMMO. SSAO activity in rat brain might be regulated by the level of this inhibitor. Semicarbazide, a SSAO inhibitor, enhances the formation of •OH products of efflux/oxidation due to 1-methyl-4-phenylpyridinium ion (MPP^+). The precise physiological functions of SSAO could play an important role in the control of energy balance in adipose tissue. SSAO could play an important role in the regulation of adipocyte homeostasis.
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Inhibition of monkey brain Semicarbazide-sensitive amine oxidase by various antidepressants.
Neuroscience letters, 2000Co-Authors: Toshio Obata, Yasumitsu YamanakaAbstract:We examined whether the antidepressant drugs, such as the dicyclic drug zimeldine, the tricyclic drug imipramine, tetracyclic drug maprotiline, and the non-cyclic drug nomifensine, inhibit in vitro Semicarbazide-sensitive amine oxidase (SSAO) activity in monkey brain. The deamination of 1 μM benzylamine was not inhibited at high concentrations of clorgyline or deprenyl, while it was highly sensitive for Semicarbazide. When corresponding experiments were performed with 100 μM benzylamine, the opposite results were obtained. The most potent of inhibition of SSAO was observed by imipramine, followed by maprotiline, zimeldine and nomifensine. Inhibition of SSAO was not enhanced by varying the time of preincubation of the enzyme and various antidepressant drugs, indicating direct action on and reversible inhibition of SSAO. We found the tricyclic antidepressant drug to be the most selective inhibitors of SSAO activity in monkey brain, as compared with other type of antidepressant drugs.
Jinfeng Kang - One of the best experts on this subject based on the ideXlab platform.
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synthesis of 2 amino 1 3 4 oxadiazoles and 2 amino 1 3 4 thiadiazoles via sequential condensation and i2 mediated oxidative c o c s bond formation
Journal of Organic Chemistry, 2015Co-Authors: Jinfeng Kang, Xianhai Tian, Lina Song, Jie Wu, Wenquan Yu, Junbiao ChangAbstract:2-Amino-substituted 1,3,4-oxadiazoles and 1,3,4-thiadiazoles were synthesized via condensation of Semicarbazide/thioSemicarbazide and the corresponding aldehydes followed by I2-mediated oxidative C–O/C–S bond formation. This transition-metal-free sequential synthesis process is compatible with aromatic, aliphatic, and cinnamic aldehydes, providing facile access to a variety of diazole derivatives bearing a 2-amino substituent in an efficient and scalable fashion.
Senthil R Ayyannan - One of the best experts on this subject based on the ideXlab platform.
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design synthesis and pharmacological evaluation of 2 amino 5 nitrothiazole derived semicarbazones as dual inhibitors of monoamine oxidase and cholinesterase effect of the size of aryl binding site
Journal of Enzyme Inhibition and Medicinal Chemistry, 2018Co-Authors: Rati K P Tripathi, Vishnu M Sasi, Sukesh Kumar Gupta, Sairam Krishnamurthy, Senthil R AyyannanAbstract:AbstractA series of 2-amino-5-nitrothiazole derived semicarbazones were designed, synthesised and investigated for MAO and ChE inhibition properties. Most of the compounds showed preferential inhibition towards MAO-B. Compound 4, (1-(1-(4-Bromophenyl)ethylidene)-4-(5-nitrothiazol-2-yl)Semicarbazide) emerged as lead candidate (IC50 = 0.212 µM, SI = 331.04) against MAO-B; whereas compounds 21 1-(5-Bromo-2-oxoindolin-3-ylidene)-4-(5-nitrothiazol-2-yl)Semicarbazide (IC50 = 0.264 µM) and 17 1-((4-Chlorophenyl) (phenyl)methylene)-4-(5-nitrothiazol-2-yl)Semicarbazide (IC50 = 0.024 µM) emerged as lead AChE and BuChE inhibitors respectively; with activity of compound 21 almost equivalent to tacrine. Kinetic studies indicated that compound 4 exhibited competitive and reversible MAO-B inhibition while compounds 21 and 17 showed mixed-type of AChE and BuChE inhibition respectively. Docking studies revealed that these compounds were well-accommodated within MAO-B and ChE active sites through stable hydrogen bonding an...
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Design, synthesis, and pharmacological evaluation of 2-amino-5-nitrothiazole derived semicarbazones as dual inhibitors of monoamine oxidase and cholinesterase: effect of the size of aryl binding site
'Informa UK Limited', 2018Co-Authors: Rati K P Tripathi, Vishnu M Sasi, Sukesh Kumar Gupta, Sairam Krishnamurthy, Senthil R AyyannanAbstract:A series of 2-amino-5-nitrothiazole derived semicarbazones were designed, synthesised and investigated for MAO and ChE inhibition properties. Most of the compounds showed preferential inhibition towards MAO-B. Compound 4, (1-(1-(4-Bromophenyl)ethylidene)-4-(5-nitrothiazol-2-yl)Semicarbazide) emerged as lead candidate (IC50 = 0.212 µM, SI = 331.04) against MAO-B; whereas compounds 21 1-(5-Bromo-2-oxoindolin-3-ylidene)-4-(5-nitrothiazol-2-yl)Semicarbazide (IC50 = 0.264 µM) and 17 1-((4-Chlorophenyl) (phenyl)methylene)-4-(5-nitrothiazol-2-yl)Semicarbazide (IC50 = 0.024 µM) emerged as lead AChE and BuChE inhibitors respectively; with activity of compound 21 almost equivalent to tacrine. Kinetic studies indicated that compound 4 exhibited competitive and reversible MAO-B inhibition while compounds 21 and 17 showed mixed-type of AChE and BuChE inhibition respectively. Docking studies revealed that these compounds were well-accommodated within MAO-B and ChE active sites through stable hydrogen bonding and/or hydrophobic interactions. This study revealed the requirement of small heteroaryl ring at amino terminal of semicarbazone template for preferential inhibition and selectivity towards MAO-B. Our results suggest that 5-nitrothiazole derived semicarbazones could be further exploited for its multi-targeted role in development of anti-neurodegenerative agents. A library of 2-amino-5-nitrothiazole derived semicarbazones (4–21) was designed, synthesised and evaluated for in vitro MAO and ChE inhibitory activity. Compounds 4, 21 and 17 (shown) have emerged as lead MAO-B (IC50:0.212 µM, competitive and reversible), AChE (IC50:0.264 µM, mixed and reversible) and BuChE (IC50:0.024 µM, mixed and reversible) inhibitor respectively. SAR studies disclosed several structural aspects significant for potency and selectivity and indicated the role of size of aryl binding site in potency and selectivity towards MAO-B. Antioxidant activity and neurotoxicity screening results further suggested their multifunctional potential for the therapy of neurodegenerative diseases
Murli Dhar Kharya - One of the best experts on this subject based on the ideXlab platform.
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novel limonene and citral based 2 5 disubstituted 1 3 4 oxadiazoles a natural product coupled approach to semicarbazones for antiepileptic activity
Bioorganic & Medicinal Chemistry Letters, 2013Co-Authors: Harish Rajak, Bhupendra Singh Thakur, Prabodh Chander Sharma, Avineesh Singh, Kamlesh Raghuvanshi, Rajesh Singh Pawar, Ravichandran Veerasamy, Murli Dhar KharyaAbstract:Abstract Two novel series of N4-(5-(2/3/4-substituted-phenyl)-1,3,4-oxadiazol-2-yl)-N1-(2-methyl-5-(prop-1-en-2-yl)cyclohex-2-enylidene)Semicarbazide and N4-(5-(2/3/4-substituted-phenyl)-1,3,4-oxadiazol-2-yl)-N1-(3,7-dimethylocta-3,6-dienylidene)-Semicarbazide were synthesized to meet structural prerequisite indispensable for anticonvulsant activity. The anticonvulsant activities of the compounds were investigated using maximal electroshock seizure (MES), subcutaneous pentylenetrtrazole (scPTZ) and subcutaneous strychnine (scSTY) models. The rotorod test was conducted to evaluate neurotoxicity. Some of the selected active compounds were subjected to GABA assay to confirm their mode of action. The outcome of the present investigations proved that the four binding sites pharmacophore model is vital for anticonvulsant activity. The efforts were also made to establish structure–activity relationships among test compounds.
