RESUMEN
Objective: To preliminarily screen out the estrogen-like quality markers of small grain Cuscuta chinensis from Heilongjiang Province, so as to provide reference for its subsequent experimental research and quality control. Methods: UPLC- Q-TOFMS/MS was used to qualitatively analyze the extract of C. chinensis and the fingerprints of different polar fractions were established. The estrogenic activity of different polar fractions was evaluated with uterine coefficient, endometrial thickness and serum estrogen level of mice. The bivariate correlation analysis and gray relational analysis were used to construct the composition-activity relationship between chemicals and the effects of estrogen for screening quality markers. And the content determination methods of the five quality markers were established. Results: A total of 10 quality markers related to the estrogenic effect from C. chinensis were found in the positive and negative ion scanning modes. They were hyperoside, astragalin, stigmasterol, neocuscutoside C, apigenin, kaempferol, 6-O-(E)-p-coumaroyl-β-D-fructofuranosyl-(2→1)-α-D-glucopyranoside, quercetin, isorhamnetin, and 2,6-octadecadiynoic acid. The contents of the five quality markers were determined as follows: hyperoside (2.753 ± 0.097) mg/g, quercetin (1.139 ± 0.107) mg/g, apigenin (1.104 ± 0.047) mg/g, kaempferol (1.144 ± 0.079) mg/g and isorhamnetin (0.697 ± 0.074) mg/g. Conclusion: The quality markers of small grain C. chinensis from Heilongjiang Province can be screened out according to the composition-activity relationship, and the method for the detect the concentrations of the quality markers is accurate and stable.