Targeted and non-targeted metabolic characteristics of 6,7-dihydroxy-2,4- dimethoxyphenanthrene during simulated gastrointestinal digestion.

6,7-dihydroxy-2,4-dimethoxyphenanthrene (PC4), isolated and identified from Chinese yam, was one of the important characteristic active ingredients. The present study established simulated gastrointestinal digestion and caco-2 intestinal epithelial models to investigate the digestive and metabolic characteristics of PC4. The results indicated that PC4 was mainly digested and metabolized in the intestine, with a digestion rate of 94 %, producing active characteristic metabolites including 2,6-dimethoxy-4-phenanthrenol (MC1) and 1-methoxyphenanthrene (MC2). Molecular docking indicated that the COX-2 enzyme inhibitory activity of MC1 might be superior to that of the prototype PC4. During 24 h co-incubation of PC4 with caco-2 monolayer epithelial, the signal pathway related to lipid decomposition was up-regulated within 0-12 h, while the diabetes complications AGE-RAGE was inhibited just in 0-6 h period significantly. The research database provided scientific basis for the digestion and metabolism of PC4, and laid theoretical foundation for the scientific development of Chinese yam functional foods.