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

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

doi:10.1186/s13065-021-00742-5

Abstract

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

Highlights

One of the main goals of World Health Organization (WHO) is to end the epidemics of neglected tropical diseases, tuberculosis (TB) and malaria by 2030 [1, 2]
Results from bioassays against 7G8 P. falciparum strain reveal that an increase in concentration (10 to 100 μg mL−1) marks an increase in percentages of inhibition for MeOH extract, 2 and 3, but a decrease for 5, which should indicate that the latter is totally inactive at high concentrations
Batesiin (2) has been characterized for the first time by means of 1H, 13C-NMR and UV spectroscopies; its structure was confirmed by Density functional theory (DFT) and time dependent DFT (TD-DFT) calculations at B3LYP/6-31G(d,p), 6-31G+(d,p), 6-311G++(d,p) and MPW1PW91/6-31G+(d,p) from this study

Summary

Introduction

One of the main goals of World Health Organization (WHO) is to end the epidemics of neglected tropical diseases, tuberculosis (TB) and malaria (which remains the major public health and mortality problem in the tropics) by 2030 [1, 2]. Natural products can be isolated from plants, which are considered to be an important source of major compounds in drug development because of their successful use in treating various human ailments since millenniums. In this context, searching for new natural products from medicinal plants could provide new ways for antimalarial and antitubercular drugs. Among these plants, some species of the genus Cordia (Boraginaceae) are reported to be useful in the treatment of tuberculosis, bronchitis and malaria [9]. Chemical and pharmacological investigations were performed on the stems of Cordia batesii (Boraginaeae); chemical studies included quantum calculations applied on a newly described compound

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Conclusion