The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Takashi Ohuchi - One of the best experts on this subject based on the ideXlab platform.
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Total synthesis of (-)-neoechinulin A
Synlett, 2006Co-Authors: Toshiaki Aoki, Masaaki Kimoto, Kensuke Ohnishi, Yoichi Takakusagi, Kenji Kuroiwa, Atsuo Nakazaki, Kouji Kuramochi, Shinji Kamisuki, Yoshifumi Takeda, Takashi OhuchiAbstract:A total synthesis of neoechinulin A was accomplished with high enantiomeric excess. Our total synthesis of neoechinulin A established the absolute configuration of natural neoechinulin A. The synthetic route features aldol condensation of a 3-formyl Indole Derivative and intramolecular cyclization.
Cheolhong Cheon - One of the best experts on this subject based on the ideXlab platform.
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total synthesis of luotonin a and rutaecarpine from an aldimine via the designed cyclization
Organic Letters, 2016Co-Authors: Se Hyun Kwon, Cheolhong CheonAbstract:The total synthesis of rutaecarpine (1) and luotonin A (2) is described through controlled cyclization of a common aldimine intermediate 5 derived from ethyl-2-aminocinnamate and quinazolinone-2-carbaldehyde. The cyanide-mediated imino-Stetter reaction of aldimine 5 provided the corresponding Indole Derivative 3, from which the total synthesis of rutaecarpine (1) was completed via the formation of a 6-membered C-ring. On the other hand, microwave-assisted thermal 6π-electrocyclization of the common intermediate 5, followed by the formation of a 5-membered C′-ring, allowed the completion of the total synthesis of luotonin A (2).
Subramaniapillai Selva Ganesan - One of the best experts on this subject based on the ideXlab platform.
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oleic acid a benign bronsted acidic catalyst for densely substituted Indole Derivative synthesis
RSC Advances, 2015Co-Authors: Asaithampi Ganesan, Jagatheeswaran Kothandapani, Jagadeesh Babu Nanubolu, Subramaniapillai Selva GanesanAbstract:Oleic acid was identified to catalyse bis(indolyl)methane and densely functionalized 4H-chromene, spirooxIndole and spiro[indoline-3,4′-pyrano[2,3-c]pyrazole] Derivative synthesis in good to excellent yields. The synergy between Bronsted acidity and surfactant ability of naturally available oleic acid was exploited to carry out the aforementioned transformations.
Rei Kinjo - One of the best experts on this subject based on the ideXlab platform.
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isolation of a diborane 6 dication formation and cleavage of an electron precise b sp3 b sp3 bond
Journal of the American Chemical Society, 2016Co-Authors: Lingbing Kong, Rakesh Ganguly, Wei Lu, Yongxin Li, Rei KinjoAbstract:One-electron oxidation of organoboron L2PhB: 1 (L = oxazol-2-ylidene) afforded a dicationic diborane(6) species [L2PhB–BPhL2]·2X (X = OTf, BF4, AlCl4) 3, representing a new strategy to construct a B(sp3)–B(sp3) covalent bond. Each boron atom in 3 is in the formal oxidation state +II, and tetracoordinate with a Ph group and two oxazol-2-ylidenes. The cyclic voltammetry of 3 shows irreversible reduction and oxidation. Indeed, two-electron reduction of 3 with potassium graphite (KC8) afforded 1, making a fully reversible 1 ↔ 3 redox system, whereas two-electron oxidation with AuCl produced a boronium [L2PhBCl]OTf 4. Moreover, the reactions of 3 with isonitrile Derivatives RNC: under heating conditions gave a cyano-substituted boronium [L2PhBCN]BF4 5 and a 2-boranyl-Indole Derivative 6, depending on the substituent R. The proposed reaction mechanism involves a borinylium radical 1•+ which is generated via a homolytic cleavage of the B–B bond of 3.
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Isolation of a Diborane(6) Dication: Formation and Cleavage of an Electron-Precise B(sp3)–B(sp3) Bond
2016Co-Authors: Lingbing Kong, Rakesh Ganguly, Rei KinjoAbstract:One-electron oxidation of organoboron L2PhB: 1 (L = oxazol-2-ylidene) afforded a dicationic diborane(6) species [L2PhB–BPhL2]·2X (X = OTf, BF4, AlCl4) 3, representing a new strategy to construct a B(sp3)–B(sp3) covalent bond. Each boron atom in 3 is in the formal oxidation state +II, and tetracoordinate with a Ph group and two oxazol-2-ylidenes. The cyclic voltammetry of 3 shows irreversible reduction and oxidation. Indeed, two-electron reduction of 3 with potassium graphite (KC8) afforded 1, making a fully reversible 1 ↔ 3 redox system, whereas two-electron oxidation with AuCl produced a boronium [L2PhBCl]OTf 4. Moreover, the reactions of 3 with isonitrile Derivatives RNC: under heating conditions gave a cyano-substituted boronium [L2PhBCN]BF4 5 and a 2-boranyl-Indole Derivative 6, depending on the substituent R. The proposed reaction mechanism involves a borinylium radical 1•+ which is generated via a homolytic cleavage of the B–B bond of 3
Bo Yang - One of the best experts on this subject based on the ideXlab platform.
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a novel Indole Derivative compound gy3 improves glucose and lipid metabolism via activation of amp activated protein kinase pathway
European Journal of Pharmacology, 2013Co-Authors: Youyou Yan, Lei Tang, Bo YangAbstract:The AMP-activated protein kinase (AMPK) is a ubiquitously expressed serine/threonine protein kinase that functions as an intracellular fuel sensor. It has been demonstrated to mediate the activities of a number of pharmacological and physiological factors that exert beneficial effects on type2 diabetes mellitus. GY3 is a novel synthesized Indole compound derived from indomethacin, a non-steroid anti-inflammatory drug. In a previous study, we found that GY3 could improve insulin resistance and lower glucose levels in db/db mice, although its mechanism of action is not yet clear. In this study, we demonstrate that in vivo administration of GY3 improved serum triglyceride levels and decreased lipid accumulation in the livers of db/db mice. In vitro studies show that GY3 increased glucose consumption in HepG2 cells and 3T3-L1 adipocytes, decreased free fatty acid (FFA)-induced lipid accumulation in HepG2 cells and lipid accumulation in 3T3-L1 adipocytes. In vitro studies further show that GY3 improved glucose and lipid metabolism through an AMPK-dependent pathway but not the PI3K pathway. These findings suggest that GY3 is an effective agent for the improvement of glucose and lipid metabolism through AMPK pathway activation.
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the potential insulin sensitizing and glucose lowering effects of a novel Indole Derivative in vitro and in vivo
Pharmacological Research, 2007Co-Authors: Lei Tang, Churui Feng, Yushe Yang, Bo YangAbstract:Thiazolidinediones (TZDs) such as rosiglitazone are antidiabetic peroxisome proliferator-activated receptor gamma (PPARgamma) agonists. PPARgamma agents improve diabetes by increasing insulin sensitivity and enhancing the differentiation of preadipocytes into adipocytes. The present study aimed to identify if 1-(4-chlorobenzoyl)-5-hydroxy-2-methyl-3-Indoleacetitic acid (GY3), a newly synthesized Indole compound, could enhance adipocytes differentiation and insulin sensitivity. The results showed that both GY3 and rosiglitazone significantly increased the lipid accumulating of 3T3-L1 adipocytes induced by isobutylmethylxanthine, dexamethasone and insulin mixture, but GY3 (not rosiglitazone) failed to increase the lipid accumulation when induced by insulin alone. In addition, GY3- or rosiglitaozne-induced protein expression of GLUT4 and adiponectin was determined by Western blot analysis. GY3 activated PPARalpha weakly but did not affect PPARgamma, while rosiglitazone activated PPARgamma significantly, suggesting different mechanisms between GY3 and rosiglitazone on adipocyte differentiation. Furthermore, both GY3 and rosiglitazone enhanced the adiponectin and insulin pathway proteins expression and adiponectin secretion in mature adipocytes, but only GY3 not rosiglitazone elevated gene expression of leptin and resistin. Both GY3 and rosiglitazone enhanced glucose consumption in HepG2 cells especially in the presence of insulin. In the in vivo study, GY3 decreased serum glucose and insulin in db/db mice, indicating the insulin sensitizing effect might contribute to its antidiabetic mechanism. Altogether, these results suggest that GY3 could improve insulin resistance and lower glucose level, GY3 and its Derivatives might be developed as a substitution therapy for diseases with insulin resistance.