Identification of characteristic markers for monofloral honey of Astragalus membranaceus var. mongholicus Hsiao: A combined untargeted and targeted MS-based study

Astragalus membranaceus var. mongholicus Hsiao (Am) is a widely used traditional Chinese herbal medicine. The monofloral honey from Am plant nectar collected by honeybees (MH-Am) has potential medicinal activities. Quality control of MH-Am requires discovery of characteristic markers. In this study, calycosin and formononetin were identified as reliable chemical markers for MH-Am authentication, which were shared with its plant (P-Am), but absent in other honeys based on untargeted mass spectrometry (MS) analysis. The contents of calycosin and formononetin in MH-Am, other honeys and P-Am were determined through a targeted MS-based quantitative approach. Furthermore, free radical scavenging assays showed that calycosin functioned directly in the antioxidative activity of MH-Am. Thus, calycosin has great potential to be certified as a bioactive marker contributing to future quality control of commercial MH-Am products.