Compositional Differences Between Brazilian and Chinese Propolis

<u><b><i></i></b></u> <u><b><i>Background:</i></b></u> There has been an increased prevalence of positive patch test reactions to propolis in recent years. Different reaction rates have been described when using propolis supplied by different manufacturers. <u><b><i>Objective:</i></b></u> Compare compositions of Brazilian propolis prepared by Allergeaze and Chinese propolis prepared by Chemotechnique. <u><b><i>Methods:</i></b></u> Both samples were analyzed using electrospray ionization mass spectrometry, and compounds were identified via the mzCloud, ChemSpider, and MassList databases. Data processing with Compound Discoverer software identified the top 6 compounds based on relative abundance. <u><b><i>Results:</i></b></u> A very low compositional overlap between the 2 propolis types: 8% match with ChemSpider, 9% with MassList, and 27% with mzCloud. The six most abundant compounds in Brazilian propolis included lauryldimethylamine oxide, (9Z)-9-octadecenamide, trioctylmethylammonium cation, monocillin VI and istamycin C1, while Chinese propolis contained pinocembrin, 16-([ethylcarbamoyl]amino) hexadecanoic acid, (4E)-6-hydroxy-4-octadecenoic acid/bee glue, linoleamide, and MFCD00083068. Prenylgermacrene B was the only common compound in both samples' top 6. <u><b><i>Conclusion:</i></b></u> These findings highlight significant compositional differences between Brazilian and Chinese propolis. Chinese propolis (catalog number NA71) was discontinued by Allergeaze in October 2019 and replaced by Brazilian propolis (catalog number NH400), likely contributing to the increased prevalence of positive reactions in recent years.