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.

Profiling of extracts from twelve propolis samples collected from eight regions in Nigeria was carried out using high performance liquid chromatography (LC) coupled with evaporative light scattering (ELSD), ultraviolet detection (UV) and mass spectrometry (MS), gas chromatography mass spectrometry (GC-MS) and nuclear magnetic resonance spectroscopy (NMR). Principal component analysis (PCA) of the processed LC-MS data demonstrated the varying chemical composition of the samples. Most of the samples were active against Trypanosoma b. brucei with the highest activity being in the samples from Southern Nigeria. The more active samples were fractionated in order to isolate the component(s) responsible for their activity using medium pressure liquid chromatography (MPLC). Three xanthones, 1,3,7-trihydroxy-2,8-di-(3-methylbut-2-enyl)xanthone, 1,3,7-trihydroxy-4,8-di-(3-methylbut-2-enyl)xanthone a previously undescribed xanthone and three triterpenes: ambonic acid, mangiferonic acid and a mixture of α-amyrin with mangiferonic acid (1:3) were isolated and characterised by NMR and LC-MS. These compounds all displayed strong inhibitory activity against T.b. brucei but none of them had higher activity than the crude extracts. Partial least squares (PLS) modelling of the anti-trypanosomal activity of the sample extracts using the LC-MS data indicated that high activity in the extracts, as judged from LCMS2 data, could be correlated to denticulatain isomers in the extracts.

This study aims to identify bioactive anticancer and anti-trypanosome secondary metabolites from the fermentation culture of Aspergillus flocculus endophyte assisted by modern metabolomics technologies. The endophyte was isolated from the stem of the medicinal plant Markhamia platycalyx and identified using phylogenetics. Principle component analysis was employed to screen for the optimum growth endophyte culturing conditions and revealing that the 30-days rice culture (RC-30d) provided the highest levels of the bioactive agents. To pinpoint for active chemicals in endophyte crude extracts and successive fractions, a new application of molecular interaction network is implemented to correlate the chemical and biological profiles of the anti-trypanosome active fractions to highlight the metabolites mediating for bioactivity prior to purification trials. Multivariate data analysis (MVDA), with the aid of dereplication studies, efficiently annotated the putatively active anticancer molecules. The small-scale RC-30d fungal culture was purified using high-throughput chromatographic techniques to yield compound 1, a novel polyketide molecule though inactive. Whereas, active fractions revealed from the bioactivity guided fractionation of medium scale RC-30d culture were further purified to yield 7 metabolites, 5 of which namely cis-4-hydroxymellein, 5-hydroxymellein, diorcinol, botryoisocoumarin A and mellein, inhibited the growth of chronic myelogenous leukaemia cell line K562 at 30 μM. 3hydroxymellein and diorcinol exhibited a respective inhibition of 56% and 97% to the sleeping sickness causing parasite Trypanosoma brucei brucei. More interestingly, the antitrypanosomal activity of A. flocculus extract appeared to be mediated by the synergistic effect of the active steroidal compounds i.e. ergosterol peroxide, ergosterol and campesterol. The isolated structures were elucidated by using 1D, 2D NMR and HR-ESIMS.

Extracts from twelve samples of propolis collected from different regions of Libya were tested for their activity against Trypanosoma brucei, Leishmania donovani, Plasmodium falciparum, Crithidia fasciculata and Mycobacterium marinum and the cytotoxicity of the extracts was tested against mammalian cells. All the extracts were active to some degree against all of the protozoa and the mycobacterium, exhibiting a range of EC50 values between 1.65 and 53.6 μg/ml. The toxicity against mammalian cell lines was only moderate; the most active extract against the protozoan species, P2, displayed an IC50 value of 53.2 μg/ml. The extracts were profiled by using liquid chromatography coupled to high resolution mass spectrometry. The data sets were extracted using m/z Mine and the accurate masses of the features extracted were searched against the Dictionary of Natural Products (DNP). A principal component analysis (PCA) model was constructed which, in combination with hierarchical cluster analysis (HCA), divided the samples into five groups. The outlying groups had different sets of dominant compounds in the extracts, which could be characterised by their elemental composition. Orthogonal partial least squares (OPLS) analysis was used to link the activity of each extract against the different micro-organisms to particular components in the extracts.

No abstract