Conformational inversion processes in phytic acid: NMR spectroscopic and molecular modeling studies

Tetrahedron Letters

Volumn 40, Issue 24, 1999, Pages 4489-4492

  Bauman, Andrew T ^a   Chateauneuf, Ginger M ^a   Boyd, Brian R ^a   Brown, Richard E ^a   Murthy, Pushpalatha P N ^a  

^a MICHIGAN TECHNOLOGICAL UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

PHYTIC ACID;

ARTICLE; CONFORMATIONAL TRANSITION; IONIZATION; MOLECULAR DYNAMICS; MOLECULAR MODEL; NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY; PH;

EID: 0033546248     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0040-4039(99)00816-3     Document Type: Article

References (7)

1. 1. Barrinetos, L.G.; Murthy, P.P.N. Carbohydrate Res. 1996, 296, 39-54.
2. 2. Bauman, A.; Brown, R.; Dettman, R.; Mellen, A.; Pandey, R.; Podila, G.K.; Xiang, K.-H.; Murthy, P. Workshop on the Biochemistry of Plant Phytate and Phytases. Ed. Rasmussen, S., Kluwer Academic Publishers, Copenhagen, Denmark (In print).
3. c/k)] J/mol. In the chairto-chair interconversion of a 6-membered ring, the formation of an intermediate (boat form) is involved. The rate constant k is the rate of exchange of protons from an equatorial site to an axial site or vice-versa. Once the molecule reaches the boat form, there is an equal probability that the intermediate will revert back to the initial chair form, or continue on to the inverted conformation. As the experiment measures the rate of chair-to-chair interconversion, the probability of the reverse step can be accounted for by doubling the rate constant k.
4. c, which is the lowest temperature at which the peaks coalesce into broad bands, was determined by monitoring the NMR spectra as a function of temperature.
5. 1 increments, each consisting of four transients with a relaxation delay of 4 s between successive transients, were obtained. A shifted Gaussian window was applied in both dimensions. The data matrix was expanded to a 1024 × 1024 real matrix.
6. 6. Gaussian 94 (Rev. E.2), Frisch, M.J.; Trucks, G.W.; Schlegel, H.B.; Gill, P.M.W.; Johnson, B.G.; Robb, M.A.; Cheeseman, J.R.; Keith, T.; Petersson, G.A.; Montgomery, J.A.; Raghavachari, K.; Al-Laham, M.A.; Zakrzewski, V.G.; Ortiz, J.V.; Foresman, J.B.; Cioslowski, J.; Stefanov, B.B.; Nanayakkara, A.; Challacombe, M.; Peng, C.Y.; Ayala, P.Y.; Chen, W.; Wong, M.W.; Andres, J.L.; Replogle, E.S.; Gomperts, R.; Martin, R.L.; Fox, D.J.; Binkley, J.S.; Defrees, D.J.; Baker, J.; Stewart, J.P.; Head-Gordon, M.; Gonzalez, C.; Pople, J.A., Gaussian, Inc., Pittsburgh PA, 1995.
7. 7. MacroModel V6.0: Mohamadi, F.; Richards, N.G.J.; Guida, W.C.; Liskamp, R.; Lipton, M.; Caulfield, C.; Chang, G.; Hendrickson, T.; Still, W.C. "MacroModel-An Integrated Software System for Modeling Organic and Bioorganic molecules using Molecular Mechanics" J. Comput. Chem. 1990, 11, 440-467.