Chromatographic analysis with different detectors in the chemical characterisation and dereplication of African propolis.
Propolis or bee glue has very diverse composition and is potentially a source of biologically active compounds. Comprehensive chemical profiling was performed on 22 African propolis samples collected from the sub-Saharan region of Africa by using various hyphenated analytical techniques including Liquid Chromatography (LC)-UltraViolet Detection (UV)-Evaporative Light Scattering Detection (ELSD), LC-High Resolution Mass Spectrometry (HRMS), Gas Chromatography (GC)-MS and LC-Diode Array Detector (DAD)-HRMS/MS. The diversity of the composition of these African propolis samples could be observed by heat mapping the LC-UV and ELSD data. The characteristic chemical components were uncovered by applying Principal Component Analysis (PCA) to the LC-HRMS data and a preliminary dereplication was carried out by searching their accurate masses in the Dictionary of Natural Products (DNP). A further identification was achieved by comparing their GC-MS or LC-DAD-HRMS/MS spectra with previously published data. Generally no clear geographic delineation was observed in the classification of these African propolis samples. Triterpenoids were found as the major chemical components in more than half of the propolis samples analysed in this study and some others were classified as temperate and Eastern Mediterranean type of propolis. Based on the comparative chemical profiling and dereplication studies one uncommon propolis from southern Nigeria stood out from others by presenting prenylated isoflavonoids, which indicated that it was more like Brazilian red propolis, and more significantly a high abundance of stilbenoid compounds which could be novel in propolis.
University of Strathclyde, Department of Pharmaceutical Sciences, Strathclyde Institute of Pharmacy and Biomedical Science, 27 Taylor Street, Glasgow G4 0NR, UK. Electronic address: tong.zhang.101@strath.ac.uk.
Tong
T
Zhang
University of Strathclyde, Department of Pharmaceutical Sciences, Strathclyde Institute of Pharmacy and Biomedical Science, 27 Taylor Street, Glasgow G4 0NR, UK.
Ruwida
R
Omar
University of Strathclyde, Department of Pharmaceutical Sciences, Strathclyde Institute of Pharmacy and Biomedical Science, 27 Taylor Street, Glasgow G4 0NR, UK.
Weam
W
Siheri
University of Strathclyde, Department of Pharmaceutical Sciences, Strathclyde Institute of Pharmacy and Biomedical Science, 27 Taylor Street, Glasgow G4 0NR, UK.
Sultan
S
Al Mutairi
University of Strathclyde, Department of Pharmaceutical Sciences, Strathclyde Institute of Pharmacy and Biomedical Science, 27 Taylor Street, Glasgow G4 0NR, UK.
Carol
C
Clements
BeeVital, Whitby, North Yorkshire YO22 5JR, UK.
James
J
Fearnley
University of Strathclyde, Department of Pharmaceutical Sciences, Strathclyde Institute of Pharmacy and Biomedical Science, 27 Taylor Street, Glasgow G4 0NR, UK.
RuAngelie
R
Edrada-Ebel
University of Strathclyde, Department of Pharmaceutical Sciences, Strathclyde Institute of Pharmacy and Biomedical Science, 27 Taylor Street, Glasgow G4 0NR, UK.
David
D
Watson
D017954:Africa South of the Sahara; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D013058:Mass Spectrometry / Q000379:methods; D025341:Principal Component Analysis; D011429:Propolis / Q000737:chemistry*; D013267:Stilbenes / Q000032:analysis*
D013267:Stilbenes; D011429:Propolis
Chemical profiling; Dereplication; Liquid Chromatography–High Resolution Mass Spectometry (LC–HRMS); Principal Component Analysis (PCA); Propolis; Stilbenoid