13089-53-7Relevant academic research and scientific papers
Donor-Acceptor Distance Sampling Enhances the Performance of "better than Nature" Nicotinamide Coenzyme Biomimetics
Geddes, Alexander,Paul, Caroline E.,Hay, Sam,Hollmann, Frank,Scrutton, Nigel S.
, p. 11089 - 11092 (2016)
Understanding the mechanisms of enzymatic hydride transfer with nicotinamide coenzyme biomimetics (NCBs) is critical to enhancing the performance of nicotinamide coenzyme-dependent biocatalysts. Here the temperature dependence of kinetic isotope effects (
MECHANISM AND TRANSITION-STATE STRUCTURE OF HYDRIDE-TRANSFER REACTIONS MEDIATED BY NAD(P)H - MODELS
Verhoeven, J. W.,Gerresheim, W. van,Martens, F. M.,Kerk, S. M. van der
, p. 975 - 992 (2007/10/02)
The energy to transfer one electron from NAD(P)H and related 1,4-dihydropyridines to a series of substrates is calculated and compared with the experimental activation energy for transfer of a hydride equivalent between these species.It is concluded that single electron-transfer (SET) cannot occur as a primary step in the overall hydride-transfer process except for substrates with very strong one-electron oxidizing properties.A simple valence-bond configuration mixing (VBCM) model is presented, that rationalizes the general occurrence of concerted hydride transfer as the lowest energy reaction-pathway and furthermore explains why the activtion energy of such a concerted pathway is often linearly related to that of a -hypothetical- SET process.For one intramolecular and two related, intermolecular hydride-transfer reactions the temperature dependence of the primary kinetic isotope effect (TDKIE) was studied.For the intramolecular reaction, where a face to face orientation of the reactants is enforced, the TDKIE parameters suggest the occurence of a bent hydride-transfer pathway.For both intermolecular reactions, however, a linear transition-state geometry is indicated.MNDO calculations of the reaction profile for hydride transfer from a 1,4-dihydropyridine to either a positively charged substrate (i.e. the pyridinium-ion) or to a neutral substrate (i.e. 1,1-dicyanoethylene) confirm, that a linear transition-state geometry is favoured, unless the system is geometrically restrained to prevent such a geometry.The MNDO calculations furthermore indicate that in a linear transition-state almost unimpeded rotation can occur about the C...H...C axis.This rotation interconverts the relative orientation of the reactants between parallel-exo and tilted-endo, which may have important consequences for the interpretation of the stereochemical outcome of reactions involving (pro)chiral reactants.
TEMPERATURE DEPENDENCE OF THE PRIMARY KINETIC ISOTOPE EFFECT FOR HYDRIDE TRANSFER MEDIATED BY A NAD(P)H-MODEL; DISCRIMINATION BETWEEN BENT AND LINEAR TRANSITION STATES
Gerresheim, W. van,Verhoeven, J. W.
, p. 339 - 340 (2007/10/02)
Temperature dependence of the primary kinetic isotope effect for hydride transfer from 1-benzyl-1,4-dihydronicotinamide (a NAD(P)H-model) to the 10-methyl-9-phenylacridinium ion conclusively shows the reaction to proceed through a linear transition state.
