Precursors of the pyrimidine and thiazole rings of thiamine

Adaptive Biosynthesis of Thiazole and Bypassing of the Thiazole Requirement in Exobasidium by Acetyl Phosphate, Tween and Ethanol

“…The addition of methionine or homocysteine drastically reduces the lag phase (Sundstrom 1968). This agrees with the findings of Johnson et al (1966) and Tomlinson et al (1967), who suggested that methionine as well as alanine is a precursor in thiazole synthesis. Consequently in Exobasidium the regulation of methionine synthesis may affect the biosynthesis of thiazole.…”

“…In most cases in which growth occurs there seems to be a pre-requisite for synthesis of acetyl-CoA and acetylhomoserine, which are the probable precursors of methionine. As it is well documented that methionine is a precursor for thiazole synthesis (Tomlinson et al 1967), why does the synthesized methionine not induce synthesis of thiazole in E. vaccinii "myrt"? This problem will now be touched upon.…”

Thiamin biosynthesis in Saccharomyces cerevisiae. Origin of carbon-2 of the thiazole moiety

“…In some cases, the target compound [in this case 5-(fl-hydroxyethyl)-4-methylthiazole] was not isolated, but it was assumed that a chromatographic fraction containing the desired product did not contain any other radioactive compound (Johnson et al, 1966;Iwashima & Nose, 1971). Alternatively, the desired compound was isolated, but no derivatives were prepared and no degradation attempted, and it was assumed that the isolated product was free of radiochemical contaminants (Tomlinson et al, 1967).…”

Effect of Aliphatic Amino Acids and Citric Acid Cycle Compounds on Early Thiamine Production by Thiazoleless Mutant of Escherichia coli

“…The reason might be attributed to the different strain of E. coli. Recently, a result which was obtained by Tomlinson using pulsing log phase cultures of Bacillus subtilis indicated that pyrimidine ring of thiamine was primarily derived from aspartate (12).…”