uthai wichai - Academia.edu (original) (raw)

Papers by uthai wichai

Research paper thumbnail of Biotransformation of various natural sterols to androstenones by Mycobacterium sp. and some steroid-converting microbial strains

Journal of Molecular Catalysis B-enzymatic, 2006

The selected standard bacterial strains (Arthrobacter citreus TISTR 820, Bacillus sphaericus ATCC... more The selected standard bacterial strains (Arthrobacter citreus TISTR 820, Bacillus sphaericus ATCC 13805, Bacilllus stearothermophilus TISTR 329, Corynebacterium aquaticum TISTR 823, Pseudomonas acidovorans TISTR 356, Streptomyces peucetius TISTR 3355) and fungal strains (Aspergillus niger TISTR 3254, Aspergillus terreus TISTR 3109, Cunninghemella elegans TISTR 3370, Curvularia lunata TISTR 3292, Penicillin siamensis TISTR 1253, Rhizopus arrhizus TISTR 3188) were screened for sterol side-chain cleavage activity using ␤-sitosterol as a model substrate. In various solubility conditions, the main predicted products, 4-androstene-3,17-dione (AD), 1,4-androstadiene-3,17-dione (ADD) and testosterone (TS) were not obtained in all screening species. Both of Mycobacterium sp. NRRL B-3683 and Mycobacterium sp. NRRL B-3805 were able to convert ␤-sitosterol to AD and ADD. The principal product from Mycobacterium sp. NRRL B-3683 was AD, meanwhile Mycobacterium sp. NRRL B-3805 was ADD. Structural feature of sterol substrates affected to androstenone production. Compared to all tested sterols, ␤-sitosterol was higher converted into total androstenones in yield of 75.87 and 83.86% by Mycobacterium sp. NRRL B-3683 and Mycobacterium sp. NRRL B-3805, respectively. Almost equivalent of maximum AD and ADD with total conversion of 81.83% was observed in mixed cultures of both strains.

Research paper thumbnail of ChemInform Abstract: An Improved Route to 1,2-Dideoxy-β-1-phenyl-D-ribofuranose

Cheminform, 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Research paper thumbnail of ChemInform Abstract: Disiloxane-Protected 2-Deoxyribonolactone as an Efficient Precursor to 1,2-Dideoxy-1-β-aryl-D-ribofuranoses

Cheminform, 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Research paper thumbnail of Disiloxane-Protected 2-Deoxyribonolactone as an Efficient Precursor to 1,2-Dideoxy-1-β-aryl- d -ribofuranoses

Organic Letters, 1999

[formula: see text] Aryl C-nucleosides are analogues of natural nucleosides where the bases have ... more [formula: see text] Aryl C-nucleosides are analogues of natural nucleosides where the bases have been replaced with aromatic moieties. Work herein describes the highly stereoselective syntheses of non-hydrogen-bonding carbocyclic derivatives using a disiloxane-protected 2-deoxy-D-ribono-1,4-lactone as a stable and readily accessible starting material. Unlike the bis(TBDMS)-protected congener, this compound enables the use of sterically congested ortho-substituted aryllithium reagents in the initial addition reaction.

Research paper thumbnail of An improved route to 1,2-dideoxy-β-1-phenyl- d-ribofuranose

Bioorganic & Medicinal Chemistry Letters, 1998

An efficient synthesis of the aryl nucleoside analogue 1,2-dideoxy-~-1-phenyl-D-ribofuranose ( 1 ... more An efficient synthesis of the aryl nucleoside analogue 1,2-dideoxy-~-1-phenyl-D-ribofuranose ( 1 ) is described. This route utilizes the addition of phenyllithium to a protected 2-deoxyribonolactone Iollowed by reduction with triethylsilane/boron trifluoride etherate to selectively produce the ]3-anomer. Deprotection yields the desired aryl C-nucleoside in 27% overall yield from 2-deoxy-D-ribose. © 1998 Elsevier Science Ltd. All rights reserved.

Research paper thumbnail of Biotransformation of various natural sterols to androstenones by Mycobacterium sp. and some steroid-converting microbial strains

Journal of Molecular Catalysis B-enzymatic, 2006

The selected standard bacterial strains (Arthrobacter citreus TISTR 820, Bacillus sphaericus ATCC... more The selected standard bacterial strains (Arthrobacter citreus TISTR 820, Bacillus sphaericus ATCC 13805, Bacilllus stearothermophilus TISTR 329, Corynebacterium aquaticum TISTR 823, Pseudomonas acidovorans TISTR 356, Streptomyces peucetius TISTR 3355) and fungal strains (Aspergillus niger TISTR 3254, Aspergillus terreus TISTR 3109, Cunninghemella elegans TISTR 3370, Curvularia lunata TISTR 3292, Penicillin siamensis TISTR 1253, Rhizopus arrhizus TISTR 3188) were screened for sterol side-chain cleavage activity using ␤-sitosterol as a model substrate. In various solubility conditions, the main predicted products, 4-androstene-3,17-dione (AD), 1,4-androstadiene-3,17-dione (ADD) and testosterone (TS) were not obtained in all screening species. Both of Mycobacterium sp. NRRL B-3683 and Mycobacterium sp. NRRL B-3805 were able to convert ␤-sitosterol to AD and ADD. The principal product from Mycobacterium sp. NRRL B-3683 was AD, meanwhile Mycobacterium sp. NRRL B-3805 was ADD. Structural feature of sterol substrates affected to androstenone production. Compared to all tested sterols, ␤-sitosterol was higher converted into total androstenones in yield of 75.87 and 83.86% by Mycobacterium sp. NRRL B-3683 and Mycobacterium sp. NRRL B-3805, respectively. Almost equivalent of maximum AD and ADD with total conversion of 81.83% was observed in mixed cultures of both strains.

Research paper thumbnail of ChemInform Abstract: An Improved Route to 1,2-Dideoxy-β-1-phenyl-D-ribofuranose

Cheminform, 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Research paper thumbnail of ChemInform Abstract: Disiloxane-Protected 2-Deoxyribonolactone as an Efficient Precursor to 1,2-Dideoxy-1-β-aryl-D-ribofuranoses

Cheminform, 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Research paper thumbnail of Disiloxane-Protected 2-Deoxyribonolactone as an Efficient Precursor to 1,2-Dideoxy-1-β-aryl- d -ribofuranoses

Organic Letters, 1999

[formula: see text] Aryl C-nucleosides are analogues of natural nucleosides where the bases have ... more [formula: see text] Aryl C-nucleosides are analogues of natural nucleosides where the bases have been replaced with aromatic moieties. Work herein describes the highly stereoselective syntheses of non-hydrogen-bonding carbocyclic derivatives using a disiloxane-protected 2-deoxy-D-ribono-1,4-lactone as a stable and readily accessible starting material. Unlike the bis(TBDMS)-protected congener, this compound enables the use of sterically congested ortho-substituted aryllithium reagents in the initial addition reaction.

Research paper thumbnail of An improved route to 1,2-dideoxy-β-1-phenyl- d-ribofuranose

Bioorganic & Medicinal Chemistry Letters, 1998

An efficient synthesis of the aryl nucleoside analogue 1,2-dideoxy-~-1-phenyl-D-ribofuranose ( 1 ... more An efficient synthesis of the aryl nucleoside analogue 1,2-dideoxy-~-1-phenyl-D-ribofuranose ( 1 ) is described. This route utilizes the addition of phenyllithium to a protected 2-deoxyribonolactone Iollowed by reduction with triethylsilane/boron trifluoride etherate to selectively produce the ]3-anomer. Deprotection yields the desired aryl C-nucleoside in 27% overall yield from 2-deoxy-D-ribose. © 1998 Elsevier Science Ltd. All rights reserved.