Ab initio studies of receptor interactions with AMPA ((S)-2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl) propionic acid) and kainic acid (2S-(2 alpha, 3 beta, 4 beta))-2-carboxy-4-(1-methylethenyl)-3-pyrrolidineacetic acid.

The optimum geometries and binding energies of the complexes formed by AMPA and Kainic acid, as well as their anions with tyrosine, proline and some tripeptides are investigated with quantum chemical calculations (HF/6-31G**). It was found that receptors featuring the Tyr-Ala-Pro sequence exhibit stronger binding energies to the substrates than the Tyr-Ser-Pro and Tyr-Ser-Ser. As expected, the anions are more bound than the neutral species.

A step on the path in the discovery of new latent fingerprint development reagents: substituted Ruhemann's purples and implications for the law.

Energies corresponding to optimum geometries of ninhydrin, some of its analogs, the corresponding Ruhemann's Purple analogs and some of the intermediates of the reaction between ninhydrin analogs and amino acids are calculated at Hartree-Fock/6-31G** level of theory. Such a study is significant from a forensic science point of view because of the strong interest in the forensic chemistry and law enforcement communities in developing alternatives to the current generation of ninhydrin-like chemicals for the detection and development of latent fingerprints. In examining our new predictions for the net energetics of the reactions in the formation of substituted Ruhemann's Purples, we find that a fluorine-containing analog is the most thermodynamically feasible reaction.

Ab initio studies of some amino acid residue complexes with 4-mercaptopyridine as a model for thymitaq (AG337), an inhibitor of thymidylate synthase.

The complex formed by isopentane, as a model for the isoleucine residue present in the wild-type thymidylate synthase, with 4-mercaptopyridine as a fragment of the thymidylate synthase inhibitor Thymitaq (AG337) is investigated with ab initio quantum chemical calculations at Hartree-Fock and MP2 levels, using the 3-21G* basis set. The binding energy is compared with the binding energies of 4-mercaptopyridine with amino acid residues found in mutant thymidylate synthase enzymes. As compared with isoleucine, alanine and glycine do not show binding, in agreement with enzyme-inhibition results.

Quantum chemical studies employing an ab initio combination approach on the binding of the bis-benzimidazole Hoechst 33258 to the minor groove of DNA.

Ab initio calculations (Hartree-Fock) using the 3-21G and the STO-3G Gaussian basis sets were performed on the sequence selective minor groove binding bis-benzimidazole Hoechst 33258. Geometry optimized conformations, energies and distribution of electrostatic charges within the molecule were derived. The binding of the optimized conformations of the drug to both alternating and non-alternating (AT)n sequences was studied.