Chemical characterisation of Nigerian red propolis and its biological activity against Trypanosoma Brucei

Omar, Ruwida M K and Igoli, John and Gray, Alexander I and Ebiloma, Godwin Unekwuojo and Clements, Carol and Fearnley, James and Edrada Ebel, Ru Angeli and Zhang, Tong and De Koning, Harry P and Watson, David G (2016) Chemical characterisation of Nigerian red propolis and its biological activity against Trypanosoma Brucei. Phytochemical Analysis, 27 (2). 107–115. ISSN 0958-0344 (https://doi.org/10.1002/pca.2605)

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Abstract

INTRODUCTION: A previous study showed the unique character of Nigerian red propolis from Rivers State, Nigeria (RSN), with regards to chemical composition and activity against Trypanosoma brucei in comparison with other African propolis. OBJECTIVE: To carry out fractionation and biological testing of Nigerian propolis in order to isolate compounds with anti-trypanosomal activity. To compare the composition of the RSN propolis with the composition of Brazilian red propolis. METHODOLOGY: Profiling was carried out using HPLC-UV-ELSD and HPLC-Orbitrap-FTMS on extracts of two samples collected from RSN with data extraction using MZmine software. Isolation was carried out by normal phase and reversed phase MPLC. Elucidation of the compounds with a purity > 95% was performed by 1D/2D NMR HRMS and HRLC-MS(n) . RESULTS: Ten phenolic compounds were isolated or in the case of liquiritigenin partially purified. Data for nine of these correlated with literature reports of known compounds i.e. one isoflavanone, calycosin (1); two flavanones, liquiritigenin (2) and pinocembrin (5); an isoflavan, vestitol (3); a pterocarpan, medicarpin (4); two prenylflavanones, 8-prenylnaringenin (7) and 6-prenylnaringenin (8); and two geranyl flavonoids, propolin D (9) and macarangin (10). The tenth was elucidated as a previously undescribed dihydrobenzofuran (6). The isolated compounds were tested against Trypanosoma brucei and displayed moderate to high activity. Some of the compounds tested had similar activity against wild type T. brucei and two strains displaying pentamidine resistance. CONCLUSION: Nigerian propolis from RSN has some similarities with Brazilian red propolis. The propolis displayed anti-trypanosomal activity at a potentially useful level.

ORCID iDs

Omar, Ruwida M K, Igoli, John, Gray, Alexander I, Ebiloma, Godwin Unekwuojo, Clements, Carol, Fearnley, James, Edrada Ebel, Ru Angeli, Zhang, Tong, De Koning, Harry P and Watson, David G ORCID logoORCID: https://orcid.org/0000-0003-1094-7604;