37589-77-8Relevant academic research and scientific papers
Straightforward Regeneration of Reduced Flavin Adenine Dinucleotide Required for Enzymatic Tryptophan Halogenation
Ismail, Mohamed,Schroeder, Lea,Frese, Marcel,Kottke, Tilman,Hollmann, Frank,Paul, Caroline E.,Sewald, Norbert
, p. 1389 - 1395 (2019/02/10)
Flavin-dependent halogenases are known to regioselectively introduce halide substituents into aromatic moieties, for example, the indole ring of tryptophan. The process requires halide salts and oxygen instead of molecular halogen in the chemical halogena
Mimicking nature: Synthetic nicotinamide cofactors for C=C bioreduction using enoate reductases
Paul, Caroline E.,Gargiulo, Serena,Opperman, Diederik J.,Lavandera, Iván,Gotor-Fernández, Vicente,Gotor, Vicente,Taglieber, Andreas,Arends, Isabel W. C. E.,Hollmann, Frank
supporting information, p. 180 - 183 (2013/04/24)
A series of synthetic nicotinamide cofactors were synthesized to replace natural nicotinamide cofactors and promote enoate reductase (ER) catalyzed reactions without compromising the activity or stereoselectivity of the bioreduction process. Conversions and enantioselectivities of >99% were obtained for C=C bioreductions, and the process was successfully upscaled. Furthermore, high chemoselectivity was observed when employing these nicotinamide cofactor mimics (mNADs) with crude extracts in ER-catalyzed reactions.
Dithionite adducts of pyridinium salts: Regioselectivity of formation and mechanisms of decomposition
Carelli, Vincenzo,Liberatore, Felice,Scipione, Luigi,Di Rienzo, Barbara,Tortorella, Silvano
, p. 10331 - 10337 (2007/10/03)
1H and 13C NMR spectroscopy has been used to detect and to characterize the adducts formed, in alkaline solutions, by the attack of dithionite anion on 3-carbamoyl or 3-cyano substituted pyridinium salts. In all studied cases, only 1,4-dihydropyridine-4-sulfinates, formed by attack of dithionite oxyanion on the carbon 4 of pyridinium ring, were found. This absolute regioselectivity seems to suggest a very specific interaction between the pyridinium cation and the dithionite through the formation of a rigidly oriented ion pair, determining the position of attack. In weak alkaline solution, the adducts decompose according to two mechanisms SNi and SNi′: the SNi path is operative in all studied cases and preserves the 1,4-dihydro structure yielding the corresponding 1,4-dihydropyridines, whereas the SNi′ path involves the shift of 2,3 or 5,6 double bonds yielding 1,2- or 1,6-dihydropyridines, respectively. The formation of 1,2- or 1,6-dihydropyridines, in addition to 1,4-dihydro isomers, depends on their respective thermodynamic stabilities.
Process of synthesis of vinblastine and vincristine
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, (2008/06/13)
The present invention relates to the synthesis of dimer alkaloid compounds, particularly those of the Catharantus (Vinca) family, from an indole unit, such as cantharanthine, and a dihydroindole unit, such as vindoline. A multi-step process is disclosed including the steps of (1) of 1,4-reduction of a first dimeric iminium intermediate to an enamine compound by reaction with a 1,4-dihydropyridine compound; (2) oxidative transformation of the resulting enamine to a second iminium intermediate under controlled aeration; (3) reduction of the second iminium intermediate to form the target dimer alkaloid compounds. The entire process can be conducted in a one-pot operation to obtain the target compounds without isolation of the intermediates.
Structure Sensitivity of the Marcus λ for Hydride Transfer between NAD+ Analogues
Kreevoy, Maurice M.,Ostovic, Drazen,Lee, In-Sook Han,Binder, David A.,King, Gary W.
, p. 524 - 530 (2007/10/02)
Thirty-five rate constants, kij, for transfer of hydride between various pyridinium, quinilinium, acridinium, and phenantridinium ions spanning a range of over 10E11 in their equilibrium constants Kij and over 10E6 in kij
Marcus Theory of Hydride Transfer from an Anionic reduced Deazaflavin to NAD+ Analogues
Lee, In-Sook Han,Ostovic, Drazen,Kreevoy, Maurice
, p. 3989 - 3993 (2007/10/02)
Eighteen rate constants, kij for hydride transfer from the conjugate base of 1,5-dihydro-3,10-dimethyl-5-diazaisoalloxazine to a variety of pyridinium, quinolinium, phenanthridinium, and acridinium ions have been determined. (All the oxidizing agents can be regarded as analogues of NAD+.) The kij values span 7 powers of 10 and the corresponding equilibrium constants, Kij, span more than 13 powers of 10.For reactions with ΔG0 near zero, the kij values are close to those given by modified Marcus theory (ref 10).However, with more negative ΔG0 values, the observed kij increase more strogly than the calculated values.Agreement can be produced by making the standard free energy of precursor complex formation, symbolized WT +- here, to indicate that it applies to reactants of opposite charge, a linear function of ΔG0, and treating the slope and interrcept of the linear relation as adjustable parameters.The best fit is obtained with WT+-(in kJ*mol-1)=-9.4+0.11ΔG0.An avarage discrepancy between calculated and observed ln kij values of 0.5 is achieved, which is a good as the overall fit achieved for hydride transfer from neutral NADH analogues to NAD+ analogues (ref 10).The form and the parameterization of Wf are shown to be a physically reasonable approximation for reactions with ΔG00.These results strengthen the conclusion (ref 10) that a wide range of hydride transfer rates can be quantitavely understood without introducing high-energy metastable intermediates (radicals and radical ions).
Kinetics of the reduction of nicotinonitrile cations by 1,4-dihydronicotinamides
Bunting, John W.,Brewer, John C.
, p. 1245 - 1249 (2007/10/02)
The rates of reduction of a series of 1-(Z-benzyl)nicotinonitrile cations by a series of 1-(X-benzyl)-1,4-dihydronicotinamides have been studied at 25 deg C in 20percent CH3CN - 80percent H2O (pH 7.0 (5 mM phosphate), ionic strength 1.0 (KCl)).Spectral st
Hydride Transfer and Oxyanion Addition Equilibria of NAD+ Analogues
Ostovic, Drazen,Lee, In-Sook Han,Roberts, Roger M. G.,Kreevoy, Maurice M.
, p. 4206 - 4211 (2007/10/02)
Equilibrium constants, K, have been determined for the reduction of 10-methylacridinium ion by 15 N-heterocyclic hydride donors: acridine, quinoline, pyridine, and phenanthridine derivatives.The solvent was a mixture of 2-propanol and water in the ratio 4 : 1 by volume.Reduction potentials have been estimated for the corresponding cations in aqueous solution by assuming that the K's would be the same and accepting -361 mV as the reduction potential of the 3-(aminocarbonyl)-1-benzylpyridinium ion.These reduction potentials span 430 mV.Values of pKR have also been determined for six of the cations in the same solvent.For derivatives of the same ring system, -ΔlogK is approximately equal to ΔpKR, but a 4 log unit discrepancy appears when phenanthridine derivatives are compared with the 9-methylacridinium ion.
