On the spectral properties of tryptamine derivatives
Article first published online: 19 OCT 2004
Copyright © 1993 John Wiley & Sons, Inc.
International Journal of Quantum Chemistry
Supplement: Proceedings of the International Syposium on the Application of Fundamental Theory to Problems of Biology and Pharmacology
Volume 48, Issue Supplement 20, pages 107–116, 13/20 March 1993
How to Cite
Da Motta Neto, J. D. and De Alencastro, R. B. (1993), On the spectral properties of tryptamine derivatives. Int. J. Quantum Chem., 48: 107–116. doi: 10.1002/qua.560480713
- Issue published online: 19 OCT 2004
- Article first published online: 19 OCT 2004
- Manuscript Received: 23 JUN 1993
We report quantum chemical semiempirical calculations of the electronic structure of serotonin (5-hydroxytryptamine, 5-HT) and 5,7-dihydroxytryptamine (5,7-DHT). Those substances are important in the context of Alzheimer's disease. Moreover, the tautomerism of 5,7-DHT, which is not present in serotonin, is also examined. We have found that the phenol form of 5,7-DHT is more stable than is the 4-keto form in the gas phase. However, the large dipole moment of the keto form suggests that a large stabilization of this form can occur in a polar environment, which is confirmed by further supermolecule calculations. We have also calculated the absorption spectra of both 5,7-DHT and serotonin (5-HT) using the INDO/S method at the calculated AM1 geometries, with good agreement with experimental data. Our results give strong support to the hypothesis of the phenol–keto tautomerism of 5,7-DHT being responsible for the UV-visible spectroscopic features. © 1993 John Wiley & Sons, Inc.