20072-97-3Relevant articles and documents
Synthesis of modified aldonic acids and studies of their substrate efficiency for dihydroxy acid dehydratase (DHAD)
Limberg, Gerrit,Thiem, Joachim
, p. 349 - 356 (2007/10/03)
Modified aldopentonic and aldohexonic acids were synthesized in order to study the electronic requirements for a successful enzymatic conversion into their corresponding 2-keto 3-deoxy analogues by dihydroxy acid dehydratase (DHAD), an enzyme from the biosynthetic pathway of branched chain amino acids. Analytical tests with the novel artificial substrates (18)-(21) and (27) provided evidence that the amount of conversion could be enhanced by replacement of the hydroxy group at C 4 of L-arabinonic acid (21) with less electron-withdrawing, ambivalent or electron-donating substituents. Modified aldohexonic acids were no substrates for DHAD, perhaps due to less perfect binding to the active site presumably for steric reasons. For 4-deoxy-L-threo-pentonic acid (18) the enzymatic conversion into 3,4-dideoxy-2-ketopentonic acid (29) by DHAD could be achieved on a preparative scale.
Sugar Enolones, XI. 2-Halopentopyranosyl Halides: Preparation, Configurational Elucidation, and Conversion into Enantiomeric Dihydropyranones
Lichtenthaler, Frieder W.,Sakakibara, Tohru,Egert, Ernst
, p. 471 - 488 (2007/10/02)
Addition of chlorine or bromine to the enediol grouping of tribenzoyl-pentenitol 2 exclusively yields cis-adducts, i.e. 1,2-dihalides of α-D-lyxo (4, 6) and β-D-xylo configuration (5, 7).Configurational assignments were based on the titanium tetrahalide-i