caa a22 4500 463240014 CHVBK 20180405153310.0 cr unu---uuuuu 170326e20070701xx s 000 0 eng 10.1007/s10947-007-0094-9 doi (NATIONALLICENCE)springer-10.1007/s10947-007-0094-9 DFT study of oxaloacetic acid condensation — The first step of the citric acid cycle [Elektronische Daten] [V. Delchev, G. Delcheva] The mechanism of acylation of oxaloacetic acid (OA) with acetyl-CoA was studied at the DFT level using the basis functions 6-311G(d,p) and different numbers of diffuse functions. Four mechanisms are considered in this study. It is found that the most probable mechanism, in the approximation of isolated molecules, starts with the enol forms of oxaloacetic acid and acetylcystamine (final fragment from acetyl-CoA). The mechanisms are commented from the viewpoint of their thermodynamics. The calculations and UV/VIS spectroscopic analysis of OA showed that the enol form of the compound is available in ethanol, water and diethyl ether. The higher stability of the OA enol form (compared to the stability of the ketoform) was also reconfirmed by its experimental IR spectrum. The energy barrier of the enolization reaction of OA was calculated to be very high. Springer Science+Business Media, Inc., 2007 acylaton nationallicence B3LYP functional nationallicence Krebs cycle nationallicence mechanism nationallicence oxaloacetate nationallicence theoretical study nationallicence Delchev V. Department of Physical Chemistry, University of Plovdiv, Plovdiv, Bulgaria aut Delcheva G. Department of Biochemistry, University of Food Technologies, Plovdiv, Bulgaria aut Journal of Structural Chemistry Springer US 48/4(2007-07-01), 615-622 0022-4766 48:4<615 2007 48 10947 https://doi.org/10.1007/s10947-007-0094-9 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10947-007-0094-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Delchev V. Department of Physical Chemistry, University of Plovdiv, Plovdiv, Bulgaria aut NATIONALLICENCE 700 1- Delcheva G. Department of Biochemistry, University of Food Technologies, Plovdiv, Bulgaria aut NATIONALLICENCE 773 0- Journal of Structural Chemistry Springer US 48/4(2007-07-01), 615-622 0022-4766 48:4<615 2007 48 10947 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer