The substrate spectrum of mandelate racemase: Minimum structural requirements for substrates and substrate model
Mandelate racemase (EC 5.1.2.2) is one of the few biochemically well-characterized racemases. The remarkable stability of this cofactor-independent enzyme and its broad substrate tolerance make it an ideal candidate for the racemization of non-natural α-hydroxycarboxylic acids under physiological reaction conditions to be applied in deracemization protocols in connection with a kinetic resolution step. This review summarizes all aspects of mandelate racemase relevant for the application of this enzyme in preparative-scale biotransformations with special emphasis on its substrate tolerance. Collection and evaluation of substrate structure-activity data led to a set of general guidelines, which were used as basis for the construction of a general substrate model, which allows a quick estimation of the expected activity for a given substrate.
Felfer, Ulfried,Goriup, Marian,Koegl, Marion F.,Wagner, Ulrike,Larissegger-Schnell, Barbara,Faber, Kurt,Kroutil, Wolfgang
Selective Isomerization of Glycidates and Their Analogues with Triphenylsilyl Perchlorate or Electrogenerated Acid
Isomerization of glycidic esters and nitriles to the corresponding 2-hydroxy-3-alkenoates and their nitrile derivatives occurred on treatment with triphenylsilyl perchlorate or electrogenerated acid (EG acid).The cyanohydrin moiety of the nitriles 4 was transformed to a formyl group, giving the corresponding enals on treatment with weak base.