A study of GABA and its analogues using the molecular orbital method

Tsuda, Mitsunori; Takada, Takahiro; Miyazaki, Masao; Uda, Yoshiyuki; Kuzuhara, Shigeki; Kitaura, Kazuo

doi:10.1016/0166-1280(93)80013-p

Cited by 11 publications

(5 citation statements)

References 7 publications

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“…Andrews and Johnston [58] have obtained the lowest energy structure at the O1-C3-C4-N1 dihedral angle of 679.5 with employing semi empirical MINDO/3 calculations with full geometry optimization. The same dihedral angle was reported 180 with MNDO calculations [59,60]; however, this is in disagreement with MNDO calculations reported by Boulanger et al [61]. in which the energy minima has been found at the O1-C3-C4-N1 dihedral angle of 671.2 .…”

Section: Methodssupporting

confidence: 59%

DFT and Ab initio computational study on the reactivity sites of the GABA and its agonists, such as CACA, TACA, DABA, and muscimol: In the gas phase and dielectric media

Serdaroğlu

2010

Int J of Quantum Chemistry

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The reactive behavior of GABA and its agonist molecules have been investigated using B3LYP hybrid density functional method at the 6-311þþG** basis set level, in the gas phase and dielectric media. The calculations have been performed to obtain optimized geometries, relative energies, net atomic charges, HOMO, and LUMO energies. Solvent effects have been analyzed using isodensity polarized continuum model (IPCM) for four different solvents, which are chloroform, ethanol, DMSO, and H 2 O. The results have suggested that both the amino group and carboxyl group have been two of the most important active site for interactions between all compounds and their receptors. In addition they have suggested that the amino group reflects the difference in biological activity for each all molecules. The structures of these agonists have provided an essential foundation for subsequent structure-activity analysis of ligand binding at GABA receptors, neuronal uptake inhibitors and transporters.

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Section: Methodssupporting

confidence: 59%

DFT and Ab initio computational study on the reactivity sites of the GABA and its agonists, such as CACA, TACA, DABA, and muscimol: In the gas phase and dielectric media

Serdaroğlu

2010

Int J of Quantum Chemistry

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“…The results of these calculations differ widely. Armstrong et al [43] find the lowest energy minimum at an O1--C5--C6--N1 dihedral angle of +61~ while Boulanger et al [44] find the lowest energy structure at 5-2.3 ~ Tsuda et al [41], using STO-3G with full geometry optimization, report a lowest energy structure with a corresponding dihedral angle of ca. 0 ~ Cioslowski and Fleischman [45] have reported HF/6-31G** calculations on the muscimol zwitterion.…”

Section: Ab Initio Calculationsmentioning

confidence: 98%

“…Lipkowitz et al [39] used the AM 1 method to study the potential energy as a function of rotation about the C5--C6 bond and found energy minima at ca. +60 ~ with barriers at 0 and 180 ~ of 1.8 and 7.0 kcal/mol, respectively 9 Recently, Tsuda et al [40,41] reported MNDO calculations displaying a preferred muscimol conformation with an O1--C5--C6--N1 dihedral angle of ca. 180 ~ .…”

Section: Ab Initio Calculationsmentioning

confidence: 98%

Structural features of muscimol, a potent GABAA receptor agonist, crystal structure and quantum chemicalab initio calculations

Brehm¹,

Frydenvang²,

Hansen³

et al. 1997

Struct Chem

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Muscimol, a constituent of the mushroom Amanita muscaria, is a semirigid analogue of the inhibitory neurotransmitter 4-aminobutyric acid (GABA). X-ray structure determinations and quantum chemical ab initio calculations (HF/6-3 IG*) have been carried out on the muscimol zwitterion. The solid-state conformations of the muscimol zwitterion are calculated to be 1.6-2.2 kcal/ mol higher in energy than that of the calculated minimum energy structure in vacuo. A comparison of the calculated and experimental structures indicates that the hydrogen bonding network in the solid state significantly affects the geometry of the molecular structure. This conclusion is supported by results of ab initio calculations on binary complexes between muscimol and an ammonium ion and between muscimol and a methoxide anion, simulating observed hydrogen bonding in the crystal structures.

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“…Figures were produced with the SYBYL software275 using atomic monopoles after Gasteiger and Marsili.274 and several other problems of pharmacological interest. [261][262][263][264][265][266][267] The MEP is used also in the CoMFA analysis268-270 that became recently very popular in structure-based molecular design. It was also pos-sible to design a transition-state analogue of nucleoside hydrolase on the basis of the MEP.…”

Section: B Solvationmentioning

confidence: 99%