Investigating the plant bioactive compounds in unifloral safflower honey from Xinjiang, China, is helpful for verifying its botanical origin and evaluating its functional properties. Therefore, this study quantifying hydroxysafflor yellow A (HSYA), anhydroxysafflor yellow B (ASYB), quercetin, kaempferol, rutin, myricetin, hyperoside, gallic acid, quinic acid, and ferulic acid in safflower honey by high-performance liquid chromatography; HSYA and ASYB accounted for 16.12–28.83% and 13.63–33.09%, respectively, of the quantified plant bioactive compounds and were considered characteristic markers for authentication. These compounds also exhibit angiotensin converting enzyme (ACE) inhibitory activity; the IC50 ranges from 13.33 to 132.45 μmol L−1, and the inhibition constant (Ki) is between 17.13 and 121.34 μmol L−1. HSYA (IC50 = 20.24 μmol L−1, Ki = 19.63 μmol L−1) and ASYB (IC50 = 19.33 μmol L−1, Ki = 17.13 μmol L−1) exhibited the strongest inhibitory effects. Molecular simulation studies have shown that these bioactive compounds bind key residues in the active pocket of ACE through hydrogen bonding and hydrophobic interactions, leading to ACE inhibition. Overall, HSYA and ASYB could be considered bioactive chemical markers for verifying the botanical origin of Xinjiang, China, unifloral safflower honey, and safflower honey may be a potential functional food by inhibiting ACE.
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