J. Mrozek et A. Michalak, CHEMICAL-REACTIVITY TRENDS OF ERGOTAMINE AND BUTENOLIDE FROM ELECTROSTATIC POTENTIALS AND CHARGE SENSITIVITIES, International journal of quantum chemistry, 56(5), 1995, pp. 633-644
A set of reactivity indices, including maps of the electrostatic poten
tial and local and condensed Fukui function (FF) indices in the atomic
resolution, are reported for two vasoconstricting mycotoxins: butenol
ide and ergotamine; both the finite difference approach of Parr and Ya
ng as well as charge sensitivity analysis, determining the charge resp
onses via the inversion of the hardness tenser, have been used to gene
rate the FF data. These two routes of arriving at the atomic FF indice
s provide an opportunity to evaluate the available parametrizations of
the semiempirical NDDO-type of methods which have been used to determ
ine the input charge distribution; namely, the best parametrization sh
ould generate consistent FF predictions resulting from both approaches
. For butenolide, the MNDO parametrization was found to fulfill this c
onsistency requirement. The chemical reactivity information has been u
sed to trace possible similarities in reactivity trends of the butenol
ide molecule and the related fragment of ergotamine, toward hypothetic
al nucleophilic, electrophilic, and radical attacks. These predictions
have been compared to experimental data available for other unsaturat
ed lactones. (C) 1995 John Wiley & Sons, Inc.