PM3 and DFT Computational Studies of the Reaction Mechanism of Formaldehyde and Isoleucine

Umar Hamza (Chemistry Department, Federal University of Education, Kano, Nigeria.)
Adamu Uzairu (Chemistry Department, Ahmadu Bello University, Zaria, Nigeria)
Muhammad S. Sallau
Stephen E. Abechi
Gideon A. Shallangwa

Aceh International Journal of Science and Technology
Vol 5, No 1 (2016): April 2016

The reaction of formaldehyde and Isoleucine was studied using semi-empirical and density functional theory methods. Possible reactive sites are proposed and reaction mechanism postulated. It was found that the Isoleucine nitrogen attacks the carbonyl carbon of formaldehyde and forms a methylol intermediate that undergoes a condensation with another Isoleucine to produce a Methylenediisoleucine through a methylene bridge (cross-linking). The enthalpies of the reaction are -78.79 kJ/mol and -39.14kJ/mol for PM3 and DFT respectively also ΔSo and ΔGo, for the PM3 and DFT studies predicted. The reaction was found to be exothermic and second order.