- Biosynthesis of the thiamin thiazole in Bacillus subtilis: Identification of the product of the thiazole synthase-catalyzed reaction
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In this paper, we describe an optimized reconstitution of the thiamin thiazole synthase (ThiG) catalyzed reaction and demonstrate that the enzymatic product is an unanticipated dearomatized thiazole tautomer.
- Hazra, Amrita,Chatterjee, Abhishek,Begley, Tadhg P.
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supporting information; experimental part
p. 3225 - 3229
(2009/07/30)
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- The Biosynthesis of Thiamine. Syntheses of -1-Deoxy-D-threo-2-pentulose and Incorporation of this Sugar in Biosynthesis of Thiazole by Escherichia coli Cells
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Non-growing, washed cells of Escherichia coli, depressed for the synthesis of thiamine, were incubated in the presence of -1-deoxy-D-threo-2-pentulose (9) in a medium containing the pyrimidine moiety of thiamine, L-tyrosine, and glucose.The thiamine thus biosynthesized was extracted and cleaved to give 5-(2-hydroxyethyl)-4-methylthiazole (HET) which was examined as the trifluoroacetate derived by electron-impact mass spectrometry.The distribution of the label in the fragments indicated that the pentulose (9) was a precursor of the C5-chain of HET without C-C bond cleavage.Several routes to 1-deoxypentuloses are described.Condensation of 2,4-O-benzylidene-D-threose (23) with trideuteriomethylmagnesium iodide gave the protected 1-deoxypentitols (24) and (25).Brominolysis of the mixed dibutylstannylidenes then afforded -3,4-O-benzylidene-1-deoxy-D-threo-2-pentulose (26), which was converted into the free sugar (9) by acidic hydrolysis. 1-Deoxy-D-erythro-2-pentulose was prepared in similar manner.Condensation of 2-(-methyl)-1,3-dithian with 2,3-O-isopropylidene-D-glyceraldehyde, followed by a C-3 epimerization step also led, after deprotection, to a mixture of -1-deoxy-D-erythro- and -1-deoxy-D-threo-2-pentulose, (5) and (6).
- David, Serge,Estramareix, Bernard,Fischer, Jean-Claude,Therisod, Michel
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p. 2131 - 2138
(2007/10/02)
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