Asian Journal of Biochemistry1815-99231815-9931Academic Journals Inc.10.3923/ajb.2008.109.117HuqFazlul 2200832In present study, molecular modelling analyses based on molecular mechanics,
semi-empirical (PM3) and DFT (at B3LYP/6-31G* level) calculations have
been carried out to obtain information on relative toxicity of UDF and
its metabolites. The results of the analyses show that UDF and its metabolites
have LUMO-HOMO energy differences of the order of 4.1 to 4.2 eV so that
the compounds would all be moderately inert kinetically. The molecular
surfaces of UDF and NDUDF are found to abound in neutral green and electron-deficient
blue regions so that they can be subject to lyophilic and nucleophilic
attacks. The latter attack can be due to glutathione and nucleobases in
DNA so that the two compounds may induce cellular toxicity due to glutathione
depletion and DNA damage due to oxidation of nucleobases in DNA. The other
two metaboltes UDFM1 and UDFM3 abound in electron-rich red and yellow
regions so that they are more likely to be subject to electrophilic attacks
and may very well act as antioxidants.]]>Choi, S.J., H.Y. Ji, H.Y. Lee, D.S. Kim, W.B. Kim and H.S. Lee,2002In vitro metabolism of a novel phosphodiesterase-5 inhibitor DA-8159 in rat liver preparations using liquid chromatography/electronspray mass spectrometry.]]>16395399Hegde, S. and M. Schmidt,200641439477Huq, F. and A. Alshehri,20061359373Huq, F.,20061155163Huq, F.,20061328336Ji, H.Y., H.W. Lee, H.H. Kim, D.S. Kim, M. Yoo, W.B. Kim and H.S. Lee,200434973982Kim, J., S. Kim, H.Y. Ji, J.K. Jin, S.S. Lee, D.S. Kim, M. Yoo, W.B. Kim and H.S. Lee,200357447450Kim, Y.C., H.J. Shim, H.L. Joo, S.K. Dong, W.K. Jong, B.K. Won, I. Lee and G.L. Myung,200526309320Lee, S.J., S.K. Bae, J.W. Kwon, M. You, D.C. Lee and M.G. Lee,20055713971405Wavefunction, Inc.,2004