Biochemical oxidations preparative procedure

The aim of sample preparation is that the components of interest should be extracted from complex matrices with the least time and energy consumption but with highest efficiency and reproducibility. Conditions should be mild enough to avoid oxidation, thermal degradation, and other chemical and biochemical changes. Some procedures — CE, for example — necessitate more rigorous sample pretreatment than others. On the other hand, TLC requires an absolute minimum of sample preparation. 

The synthesis of the title compositions has been selected as representative of compounds that can readily be prepared by the flux-reaction technique. In this technique, a halide melt serves both as a flux and as a constituent component of the basic reaction. The procedure has been described in the literature1 and has served for the preparation of a variety of ternary oxides, usually in the form of small, well-defined, single crystals. The halide phosphates and vanadates of strontium represent the apatite and spodiosite structures, both interesting compositions from a biochemical and solid-state point of view. 

The first cyclic intermediate on the shikimate pathway is 3-dehydro-quinic acid (38) and it was first obtained by Weiss, Davis and Mingioli from cultures of Escherichia coli mutant 170-27 by charcoal chromatography and precipitation of the brucine salt. Probably the first chemical preparation of this biochemical intermediate was reported by Hesse in 1859 who oxidised (—)-quinic acid (42) with bromine water Several procedures have since been reported for the preparation of this metabolite Yields of almost 80 per cent of 3-hydroquinic acid (38) were reported by Whiting and Coggins after a seven-day incubation of (—)-quinic acid (42) with Acetomonas oxydans CR-49 and similar selective oxidation of the axial 3-hydroxyl group in (—)-quinic acid with nitric acid or platinum and oxygen " forms the basis of chemical methods of preparation. 

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