Vitamin B, 2, cobalamin

Figure 45-13. Vitamin B,2(cobalamin). R may be varied to give the various forms of the vitamin, eg,...

Radioisotope dilution assays are based on the principle of competition between radioactive labeled ( Co) vitamin B 2 cobalamins extracted from matrices for binding sites on the intrinsic factor (a glycoprotein). Binding is in proportion to the concentration of the radioactive and nonradio active B 2 with the concentration of intrinsic factor as the limiting factor. Free cobalamins are separated from those bound on the intrinsic factor by absorption... 

Numerous papers deal with the chemistry of vitamin B]2> cobalamins, cobinamides, and their synthetic models, the cobaloximes [Co(dmgH)2(R)(L)], including the synthesis of new species,225-228 structural studies,229-239 the stereochemistry of formation and isomerisation,240-244 and reactivity.245-248 jhe effects of viscosity,249 pressure, temperature,250,25l and base coordination252... 

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