François Frappier

Separation of biotin and its analogs by high-performance liquid chromatography: Convenient labeling for ultraviolet or fluorimetric detection

Abstract d-Biotin, dethiobiotin, d-biotin sulfoxides, and d-biotin sulfone are converted to uv-absorbing or fluorescent derivatives by reaction with ω-4-dibromoacetophenone or 4-bromomethyl methoxy coumarin. High-performance liquid chromatographic separation conditions of these esters are described using C18 bonded phase.

On the mechanism of conversion of dethiobiotin to biotin in Escherichia coli. Discussion of the occurence of an intermediate hydroxylation

Abstract The last step of the biosynthesis of biotin, i.e. the conversion of dethiobiotin to biotin was studied using E. coli . The three dethiobiotin derivatives hydroxylated at C-2 or C-5 were synthesized and tested as potential precursors of biotin. It appears that none of these compounds is able to support the growth of E. coli C124 , a mutant which does not synthesize dethiobiotin, but converts it into biotin. These results strongly disfavour the hypothesis of the activation of the saturated carbons by an hydroxylation process.

On the mechanism of conversion of dethiobiotin to biotin in Escherichia coli. III isolation of an intermediate in the biosynthesis of biotin from dethiobiotin (1,2)

Abstract An intermediate in the biosynthetic pathway between dethiobiotin and biotin has been isolated for the first time, from the incubation medium of resting cells of E. Coli C124 (bio A−, His−) with ∥3H∥ or/and ∥14C∥ dethiotiotin. This compound contains sulfur. It promotes the growth of E. Coli 124 as well as other strains which are strictly biotin requiring, i.e. blocked between dethiobiotin and biotin. The conversion of the labeled intermediate into biotin by growing cells of E. Coli C124 has been established.

On the biosynthesis of biotin in Achromobacter IVSW. A reinvestigation.

[3-14C, 35S]-L-cysteine was tested as precursor of biotin in Achromobacter IVSW. No significant incorporation was observed, in contradiction with the data previously reported. On the other hand, Achromobacter IVSW converts [3H, 14C]-dethiobiotin into biotin. This suggests that biotin is biosynthesized in Achromobacter according to the classical dethiobiotin pathway.