Abstract:The active components inhibiting angiotensin-converting enzyme (ACE) in polygonati rhizoma were screened using liquid chromatography-mass spectrometry (LC-MS) and molecular docking technology. ACE was used as the target to identify the ACE-inhibitory site in polygonati rhizoma and ultra-performance liquid chromatography-electrostatic field orbital trap high-resolution mass spectrometry (UPLC-Q-Exactive MS) was used to identify the potential ACE-inhibiting active components. Molecular docking technology was used to further verify the potential ACE-inhibiting active components. The results showed that the ethyl acetate component of polygonati rhizoma had the highest ACE inhibition rate in vitro, and the IC50 of ACE inhibition rate was 1.174 mg/mL. Through LC-MS analysis of the ethyl acetate component of polygonati rhizoma, a total of 30 compounds were identified, including tianshic acid, cimicifugic acid E, brucine, polygonatine B, and kingianoside B among the 15 compounds in the positive ion mode; N-trans-p-coumaroyloctopamine, pseudo-dolaric acid, isomer of 25R, 22S-hydroxylwattinide C, skullcapflavone I, and 3,3′,7-trimethyl-4′,5-dihydroxyflavone among the 15 compounds in the negative ion mode. Molecular docking revealed that these compounds had negative binding energy and could spontaneously bind to ACE; 80% of the compounds showed binding energy lower than -5 kcal/mol. Visual analysis of the compounds with the lowest binding energy revealed that the ACE-inhibiting active ingredient in xanthine mainly interacts with the ACE active center through three to four hydrogen bonds and inhibits its activity. These results provide a reference for future studies aimed at screening the ACE-inhibiting active components in polygonati rhizoma.
