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

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‐MSn. 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. Copyright © 2015 John Wiley & Sons, Ltd.

The Chemical Characterization of Nigerian Propolis samples and Their Activity Against Trypanosoma brucei

“…When the loadings plot for the model (Figure S5) was examined it was clear that the compounds predicted to be most responsible for anti-trypanosomal were isomers of denticulatain, which we observed previously 6 . Most of the isomers had a characteristic fragment ion at m/z 241.05 as described in our previous paper 6 where a detailed elucidation of the MS 2 spectra is given.…”

“…Most of the isomers had a characteristic fragment ion at m/z 241.05 as described in our previous paper 6 where a detailed elucidation of the MS 2 spectra is given. These compounds probably are obtained from Macaranga species 22 .…”

“…Ten phenolic compounds were isolated and identified from the Rivers State samples (Coded BRN and RSN) in our previous work 6 .…”

“…In our previous work we examined propolis collected from many parts of Africa using a range of analytical methods 5 and observed that there was no clear geographic delineation for the classification of these African propolis samples. One sample from Rivers State, Nigeria stood out as having a unique chemical composition and strong anti-trypanosomal activity and we went on to isolate ten compounds from this sample, which all displayed some degree of anti-trypanosomal activity 6 . Recently we carried out profiling and anti-protozoal testing of propolis samples from different regions in Libya 7 which had a diverse chemical composition dependent on exact geographical origin.…”

Antimicrobial Activity of Propolis From Tabora and Iringa Regions, Tanzania and Synergism with Gentamicin

“…Literature indicates that propolis is associated with a number of important biological activities including antimicrobial, antioxidant, anticancer, hepatoprotective, anti-inflammatory, immunostimulant, anticariogenic, antiprotozoan, allergenic, antibrowning, antidiabetic and antitumour activities (Ophori et al, 2010;Siripatrawan et al, 2013;Wagh, 2013;Wiȩckiewicz et al, 2013;Wojtyczka et al, 2013a, b;Omar et al, 2016). Furthermore propolis has been reported to exhibit synergism with a number of antibiotics against various bacteria species (Stepanović et al, 2003;Fernandes Júnior et al, 2005;Scazzocchio et al, 2006) and to be active against methicillin resistant Staphylococcus aureus [MRSA] (Darwish et al, 2010).…”