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30 results on '"Zhang, Huichang"'

10. Synthesis and characterization of the dimethyl-substituted bisbenzimidazole ligand and its manganese complex

Author

Kwok, Wai Him, Zhang, Huichang, Hung, Shao-ching, Payra, Pramatha, Chan, Michael K., Duan, Maosheng, Skrzypczak-Jankun, E, Johnston, Dean H., and Gallucci, Judith

Subjects
Porphyrins -- Research, Porphyrins -- Chemical properties, Methyl groups -- Research, Methyl groups -- Chemical properties, Chemistry
Abstract

The dimethyl-substituted bisbenzimidazole ligand (Me(sub 2)BBZ) has structural similarities to porphyrins and phthalocyanines, one major difference is its inherent non-planarity. The Mn - Me(sub 2)-BBZ structure reveals a distinct two dimensional 'staircase' lattice and the metal ions within this lattice display weak antiferromagnetic interactions.

Published
2000

11. Structural trends in first-row transition-metal bis(benzimidazole) complexes

Author

Payra, Pramatha, Zhang, Huichang, Wai Him Kwok, Maosheng Duan, Gallucci, Judith, and Chan, Michael K.

Subjects
Metal ions -- Research, Metal ions -- Magnetic properties, Metal ions -- Chemical properties, Porphyrins -- Chemical properties, Porphyrins -- Research, Chemistry
Abstract

The structures of a periodic series of dimethyl-substituted bis(benzimidazole) Me2BBZ complexes bound to Mn(II), Fe(II), Co(II), Ni(II) and Cu(II) are determined to examine the effects of the metal-ion binding on the magnitude of this nonplanarity. The results indicate that the relative sizes of the metal ion and the Me2BBZ ligand cavity have profound effects on the structural features of the metal-ligand complex.

Published
2000

12. Design of N-Benzoxaborole Benzofuran GSK8175—Optimization of Human Pharmacokinetics Inspired by Metabolites of a Failed Clinical HCV Inhibitor

Author

Chong, Pek Y., primary, Shotwell, J. Brad, additional, Miller, John, additional, Price, Daniel J., additional, Maynard, Andy, additional, Voitenleitner, Christian, additional, Mathis, Amanda, additional, Williams, Shawn, additional, Pouliot, Jeffrey J., additional, Creech, Katrina, additional, Wang, Feng, additional, Fang, Jing, additional, Zhang, Huichang, additional, Tai, Vincent W.-F., additional, Turner, Elizabeth, additional, Kahler, Kirsten M., additional, Crosby, Renae, additional, and Peat, Andrew J., additional

Published
2019
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13. Design of N‑Benzoxaborole Benzofuran GSK8175Optimization of Human Pharmacokinetics Inspired by Metabolites of a Failed Clinical HCV Inhibitor.

Author

Chong, Pek Y., Shotwell, J. Brad, Miller, John, Price, Daniel J., Maynard, Andy, Voitenleitner, Christian, Mathis, Amanda, Williams, Shawn, Pouliot, Jeffrey J., Creech, Katrina, Wang, Feng, Fang, Jing, Zhang, Huichang, Tai, Vincent W.-F., Turner, Elizabeth, Kahler, Kirsten M., Crosby, Renae, and Peat, Andrew J.

Published
2019
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14. Base and cation effects on the Suzuki cross-coupling of bulky arylbroonic acid with halopyridines: Synthesis of pyridylphenols

Author

Zhang, /huichang, Kwong, Fuk Yee, Tian, Yuan, and Shing Chan, Kin

Subjects
Chemical reactions -- Observations, Organometallic compounds -- Research, Palladium catalysts -- Observations, Biological sciences, Chemistry
Abstract

Notable palladium-mediated cross-coupling reactions of organic electrophiles with organometallics to form carbon-carbon bonds, are the Stille and Suzuki coupling. Pyridylphenols have been successfully synthesized, and the base effects on the Suzuki coupling of bulky boronic acid with halopyridines in nonaqueous solvent have been studied. The rate and yield of Suzuki coupling accelerated with strong base and large size cation.

Published
1998

16. Enantioselectivity increases with reactivity: electronically controlled asymmetric addition of diethylzinc to aromatic aldehydes catalyzed by a chiral pyridylphenol

Author

Zhang, Huichang, Xue, Feng, Mak, T.C.W., and Chan, Kin Shing

Subjects
Reactivity (Chemistry) -- Research, Diethylzinc -- Analysis, Aldehydes -- Reactivity, Biological sciences, Chemistry
Abstract

The new chiral pyridylphenol (R)-(+)-(4) is shown to act as a catalyst in the addition of diethylzinc to aromatic aldehydes with moderate to high enantioselectivity. Such enantioselectivity follows a linear free energy relationship and increases remarkably with more reactive aryl aldehydes. The enantioselective catalytic addition of diethylzinc to aromatic aldehydes is characterized. A remarkable feature of the reactions is that their enantioselectivity is subjected to a remote electronic effect, with the substrates bearing electron-withdrawing groups showing higher enantioselectivity than those with electron-donating groups.

Published
1996

17. Hepatitis C Replication Inhibitors That Target the Viral NS4B Protein

Author

Miller, John F., primary, Chong, Pek Y., additional, Shotwell, J. Brad, additional, Catalano, John G., additional, Tai, Vincent W.-F., additional, Fang, Jing, additional, Banka, Anna L., additional, Roberts, Christopher D., additional, Youngman, Michael, additional, Zhang, Huichang, additional, Xiong, Zhiping, additional, Mathis, Amanda, additional, Pouliot, Jeffery J., additional, Hamatake, Robert K., additional, Price, Daniel J., additional, Seal, John W., additional, Stroup, Lisa L., additional, Creech, Katrina L., additional, Carballo, Luz H., additional, Todd, Dan, additional, Spaltenstein, Andrew, additional, Furst, Sylvia, additional, Hong, Zhi, additional, and Peat, Andrew J., additional

Published
2013
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18. Rational Design of Potent Non-Nucleoside Inhibitors of HIV-1 Reverse Transcriptase

Author

Chong, Pek, primary, Sebahar, Paul, additional, Youngman, Michael, additional, Garrido, Dulce, additional, Zhang, Huichang, additional, Stewart, Eugene L., additional, Nolte, Robert T., additional, Wang, Liping, additional, Ferris, Robert G., additional, Edelstein, Mark, additional, Weaver, Kurt, additional, Mathis, Amanda, additional, and Peat, Andrew, additional

Published
2012
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20. Synthesis and resolution of novel chiral pyridylphenols and their applications in catalytic asymmetric addition of diethylzinc to aldehydes.

Author

Zhang, Huichang., Chinese University of Hong Kong Graduate School. Division of Chemistry., Zhang, Huichang., and Chinese University of Hong Kong Graduate School. Division of Chemistry.

Abstract

by Huichang Zhang., Thesis (Ph.D.)--Chinese University of Hong Kong, 1996., Includes bibliographical references (leaves 114-130)., Acknowledgment --- p.i, p.ii, Abbreviations --- p.iii, Table of Contents --- p.iv-v, Chapter Chapter I --- Introduction --- p.1, Chapter I --- The basis of asymmetric catalysis --- p.6, Chapter II --- Chiral catalyst --- p.8, Chapter II-I --- Center metal --- p.9, Chapter II-II --- Chiral ligand --- p.10, Chapter III --- Structural analysis of effective chiral ligands --- p.13, Chapter III-I --- Monodentate ligand --- p.15, Chapter III-II --- Bidentate Ligand --- p.16, Chapter 1 --- Bidentate phosphine ligand --- p.16, Chapter 2 --- Bidentate oxygen ligand --- p.17, Chapter 3 --- Bidentate nitrogen ligand --- p.19, Chapter 4 --- "Bidentate ligand with N, 0，P, or S donor atom" --- p.21, Chapter III-III --- Potentially tridentate ligand --- p.22, Chapter III-IV --- Potentially tetradentate ligand --- p.23, Chapter IV --- Tentative conclusions on the effect of structural elements --- p.24, Chapter Chapter II --- "Design, synthesis and resolution of novel chiral pyridylphenols" --- p.27, Chapter I --- Design of chiral ligand --- p.27, Chapter II --- Synthesis of chiral ligands --- p.29, Chapter II-I --- "Synthesis of the chiral N, O-donor ligands" --- p.29, Chapter 1 --- Synthesis of the chiral ligands 75a-75c --- p.29, Chapter 2 --- Synthesis of the chiral ligands 93a and 93b --- p.37, Chapter 3 --- Synthesis of the chiral ligands 97a-97c --- p.41, Chapter II-II --- "Synthesis of the chiral N, P-donor ligand 98 and N, S-donor ligand 101" --- p.42, Chapter III --- Resolution of racemates of chiral ligands --- p.44, Chapter III-I --- Resolution of of the pyridylphenol 75b --- p.44, Chapter III-II --- Resolution of of the pyridylphenol 93a --- p.48, Chapter III-III --- Racemization study of 75b and 93a --- p.52, Chapter 1 --- Racemization test of 75b --- p.52, Chapter 2 --- Racemization test of 93a --- p.52, Chapter Chapter III --- Asymmetric addition of diethylzinc to aromatic aldehydes catalyzed by chiral pyridylphenols, Chapter I --- Backgound --- p.53, Chapter II --- Asmmetric addition of Et2Zn to aldehydes catalyzed by chiral pyridylphenols --- p.61, Chapter II-I --- Asmmetric addition of Et2Zn to aldehydes catalyzed by (R)-(+)-75b --- p.61, Chapter 1 --- The influence of the solvent --- p.61, Chapter 2 --- The influence of the reaction temperature --- p.64, Chapter 3 --- The influence of the concentration of catalyst --- p.66, Chapter 4 --- Electronic effect on the enantioselectivity of asymmetric addition of Et2Zn to aromatic aldehydes --- p.67, Chapter II-II --- Asmmetric addition of Et2Zn to aldehydes catalyzed by (5)-(+)-75b --- p.73, Chapter II-III --- Asmmetric addition of Et2Zn to aldehydes catalyzed by (R)-(+)-93a --- p.75, Chapter III --- Conclusions --- p.78, Chapter Chapter V --- Experimental Section --- p.79, References --- p.114, NMR Spectra --- p.131, http://library.cuhk.edu.hk/record=b5889970, Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Published
1996

22. HepatitisC Replication Inhibitors That Target the Viral NS4B Protein.

Author

Miller, John F., Chong, Pek Y., Shotwell, J. Brad, Catalano, John G., Tai, Vincent W.-F., Fang, Jing, Banka, Anna L., Roberts, Christopher D., Youngman, Michael, Zhang, Huichang, Xiong, Zhiping, Mathis, Amanda, Pouliot, Jeffery J., Hamatake, Robert K., Price, Daniel J., Seal, John W., Stroup, Lisa L., Creech, Katrina L., Carballo, Luz H., and Todd, Dan

Published
2014
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30. Hepatitis C replication inhibitors that target the viral NS4B protein.

Author

Miller JF, Chong PY, Shotwell JB, Catalano JG, Tai VW, Fang J, Banka AL, Roberts CD, Youngman M, Zhang H, Xiong Z, Mathis A, Pouliot JJ, Hamatake RK, Price DJ, Seal JW 3rd, Stroup LL, Creech KL, Carballo LH, Todd D, Spaltenstein A, Furst S, Hong Z, and Peat AJ

Subjects
Animals, Antiviral Agents chemistry, Antiviral Agents pharmacokinetics, Area Under Curve, Disease Models, Animal, Hepacivirus physiology, Hepatitis C virology, Mice, Prodrugs chemistry, Prodrugs pharmacokinetics, Prodrugs pharmacology, Antiviral Agents pharmacology, Hepacivirus drug effects, Viral Nonstructural Proteins antagonists & inhibitors, Virus Replication drug effects
Abstract

We describe the preclinical development and in vivo efficacy of a novel chemical series that inhibits hepatitis C virus replication via direct interaction with the viral nonstructural protein 4B (NS4B). Significant potency improvements were realized through isosteric modifications to our initial lead 1a. The temptation to improve antiviral activity while compromising physicochemical properties was tempered by the judicial use of ligand efficiency indices during lead optimization. In this manner, compound 1a was transformed into (+)-28a which possessed an improved antiviral profile with no increase in molecular weight and only a modest elevation in lipophilicity. Additionally, we employed a chimeric "humanized" mouse model of HCV infection to demonstrate for the first time that a small molecule with high in vitro affinity for NS4B can inhibit viral replication in vivo. This successful proof-of-concept study suggests that drugs targeting NS4B may represent a viable treatment option for curing HCV infection.

Published
2014
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