Publications scientifiques
Eric Robert Tiam
Dominique Ngono Bikobo
Ibrahim Mbouombouo Ndassa
Norbert Mbabi Nyemeck
Auguste Abouem À Zintchem
Bruno Lenta Ndjakou
Dieudonné Emmanuel Pegnyemb
Lawrence Ayong
Patrick Betote Diboué
Research Square
Abstract Background: some chemical and pharmacological investigations were performed on the EtOAc and/or CH 2 Cl 2 extracts of the stems of Cordia batesii (Boraginaeae); one of its components was subjected to some quantum calculations to get improvement in the understanding of its 13 C–NMR and UV properties along with geometric, electronic, thermodynamic data and reactivity descriptors. Results: a new allantoin ( 1 ) derivative named batesiin ( 2 ) was characterized from the EtOAc extract; thirteen known compounds including allantoin ( 1 ) were either isolated or identified by means of MS, NMR, LC–MS and GC–MS. GC–MS was applied on a fraction of essential oil which was composed of a mixture of fatty acids ( 9 – 14 ). Density functional theory (DFT) calculations were applied on batesiin ( 2 ). Data were simulated using B3LYP and MPW1PW91 functionals; calculated chemical shifts at B3LYP/6–31G(d,p) and MPW1PW91/6–31G+(d,p) showed much better correlations with the experimental data. Time dependent DFT applied on 2 at B3LYP/6–31G+(d,p) displayed a major absorption band at λ max = 299.01 nm using chloroform as solvent, 3.01 nm higher than the experimental value. In addition, The MeOH extract of the stems and some isolated compounds were tested in vitro against Pf 7G8 CQS and Pf Dd2 CQR strains of Plasmodium falciparum ; meanwhile, the CH 2 Cl 2 extract and the mixture of fatty acids ( 9 – 14) were tested on a resistant mycobacterial strain of Mycobacterium tuberculosis codified AC45. Stems disclosed a moderate antiplasmodial activity (IC 50 = 50 μg/mL) and the mixture 9 – 14 a potent antimycobacterial activity with a MIC = 9.52 μg/mL.Conclusion: these results tend to emphasize on the use of DFT studies when trying to learn more about the chemical structure through spectroscopic data of a natural compound, especially the case of a derivative of allantoin ( 1 ); essential oil from Cordia batesii presents interesting antimycobacterial activities which need to gain more visibility; further antiplasmodial tests should rely on batesiin ( 2 ) and other components of the species.
