Experimental and computational studies of an antiplasmodial derivative of allantoin; antimycobacterial essential oil from Cordia batesii WERNHAM (Boraginaceae)

Eric Robert Tiam; Dominique Serge Ngono Bikobo; Ibrahim Mbouombouo Ndassa; Norbert Mbabi Nyemeck Ii; Auguste Abouem A Zintchem; Lawrence Ayong; Patrick Hervé Betote Diboué; Bruno Lenta Ndjakou; Joséphine Ngo Mbing; Dieudonné Emmanuel Pegnyemb

doi:10.1186/s13065-021-00742-5

Experimental and computational studies of an antiplasmodial derivative of allantoin; antimycobacterial essential oil from Cordia batesii WERNHAM (Boraginaceae)

BMC Chem. 2021 Mar 5;15(1):15. doi: 10.1186/s13065-021-00742-5.

Affiliations

¹ Department of Organic Chemistry, Faculty of Science, University of Yaoundé I, P.O Box 812, Yaounde, Cameroon.
² Department of Inorganic Chemistry, Faculty of Science, University of Yaoundé I, P.O Box 812, Yaounde, Cameroon.
³ Department of Chemistry, Higher Training College, University of Yaoundé I, P.O Box 47, Yaounde, Cameroon.
⁴ Department of Organic Chemistry, Faculty of Science, University of Yaoundé I, P.O Box 812, Yaounde, Cameroon. augabouem@yahoo.fr.
⁵ Department of Chemistry, Higher Training College, University of Yaoundé I, P.O Box 47, Yaounde, Cameroon. augabouem@yahoo.fr.
⁶ Centre Pasteur du Cameroun, Yaounde, Cameroon.
⁷ Centre for Research on Medicinal Plants and Traditional Medicine, Institute of Medical Research and Medicinal Plants Studies, Yaounde, Cameroon.

^# Contributed equally.

Abstract

Background: Chemical and pharmacological investigations were performed on the stems of Cordia batesii (Boraginaeae); chemical studies included quantum calculations applied on a newly described compound.

Results: A new derivative of allantoin (1) named batesiin (2) was characterized. Thirteen other known compounds involving allantoin (1) were either isolated or identified. GC-MS enabled the identification of six compounds from a fraction containing essential oil. MeOH extract and some isolated compounds were tested in vitro against Pf7G8 CQS and Pf Dd2 CQR strains of Plasmodium falciparum; extract disclosed a moderate antiplasmodial activity (IC₅₀ = 50 μg mL^-1). Meantime, the CH₂Cl₂ extract and essential oil fraction were tested on a resistant mycobacterial strain of Mycobacterium tuberculosis; a potent antimycobacterial activity with a MIC = 9.52 μg mL^-1 was deduced from essential oil. Density functional theory (DFT) calculations were carried on batesiin (2). 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 at B3LYP/6-31G+(d,p) displayed a major absorption band 3.01 nm higher than the experimental value.

Conclusion: Cordia batesii can be considered as promising in search of compounds with antimalarial and antitubercular properties. DFT studies are very helpful when trying to learn more about the spectroscopic insights of a derivative of allantoin (1).

Keywords: Allantoin; Batesiin; Cordia batesii; DFT; Essential oil; Molecular orbitals; Mycobacterium tuberculosis; Plasmodium falciparum; Spectroscopy.