International Science Community Association Research Journal of Chemical Sciences 2231 - 606X 7 7 2017 07 18 A density functional theory (DFT) calculation and vibrational analysis of smeathxanthone A 6 10 EN Seleem H.S. 1 Department of Chemistry, Faculty of Education, Ain Shams University, Roxy, Cairo, Egypt El-Inany G.A. 2 Department of Chemistry, Faculty of Education, Ain Shams University, Roxy, Cairo, Egypt El-Shafiy H. 3 Department of Chemistry, Faculty of Education, Ain Shams University, Roxy, Cairo, Egypt Mousa M. 4 Department of Chemistry, Faculty of Education, Ain Shams University, Roxy, Cairo, Egypt Madyan A. 5 Department of Chemistry, Faculty of Education, Ain Shams University, Roxy, Cairo, Egypt El-Shetary B.A. 6 Department of Chemistry, Faculty of Education, Ain Shams University, Roxy, Cairo, Egypt Axel Lontsi Tiwa 1 Institute of Medical Research and Medicinal Plants Studies (IMPM), P.O. Box 6163, Yaoundé, Cameroon and Department of Organic Chemistry, University of Yaoundé I, P.O Box 812, Yaoundé, Cameroon Alembert Tiabou Tchinda 2 Institute of Medical Research and Medicinal Plants Studies (IMPM), P.O. Box 6163, Yaoundé, Cameroon > Research Paper 2017 5 3 2017 07 18 Natural products are now a source of many drugs for the pharmaceutical industry. For this reason, there has been an increased focus on phytochemistry over the world, which has led to the isolation of many natural substances. Herein we report molecular structure and vibrational analysis of a secondary metabolite, smeathxanthone A. high level computational theory employing M06 coupled with 6-311G simple basis set were used. Infrared data have been computed, scaled with a standard value and compared with the experimental one. We also report Fukui functions and electrostatic potential surfaces maps to study chemically reactive moieties and qualitative structure-activity relationships (QSAR). HOMO-LUMO energy gap and optimized geometry parameters have been also computed. Copyright@ International Science Community Association