Pharmacokinetic characterization and metabolic fate of trans-Pet3R5G from the fruits of Lycium ruthenicum Murray in rats

Black Goji Berry (Lycium ruthenicum Murray) is rich in anthocyanins, primarily composed of petunidin-3-O-rutinoside (trans-p-coumaroyl)-5-O-glucoside (trans-Pet3R5G). Trans-Pet3R5G exhibits multiple biological activities. However, its in vivo exposure characteristics and metabolic pathways remain poorly understood. This study aims to elucidate the metabolic processes of trans-Pet3R5G in the body by developing a highly sensitive ultra-performance liquid chromatography-multiple reaction monitoring-mass spectrometry (UPLC-MRM-MS) method. Thirty-two male rats were randomly assigned to a control group and three Lycium ruthenicum anthocyanin extract (LAE)-treated groups at doses of 50, 100, and 300 mg·kg⁻¹·body weight, and were gavaged daily for 35 consecutive days. Blood and fecal samples were collected and analyzed by UPLC-MRM-MS. The results showed that trans-Pet3R5G and its metabolites, petunidin-3,5-di-O-glucoside (Pet3G5G), petunidin-3-O-glucoside (Pet3G), petunidin (Pet), and 3-O-methylgallic acid (Megal), exhibited a typical double absorption peak in plasma (t₁ ≈ 15 minutes, t₂ ≈ 2 hours). In contrast, the plasma concentration of 2,4,6-trihydroxybenzaldehyde (THBA) increased monotonically throughout the 6-hour observation period without reaching a maximum concentration (Cmax). Furthermore, comparative analysis revealed significantly lower concentrations of trans-Pet3R5G, Pet3G5G, Pet, and THBA in the inferior vena cava versus the hepatic portal vein (P < 0.05). Further fecal analysis showed that the excretion of trans-Pet3R5G was dose-dependent, with a 24-hour recovery rate of approximately 33.75% in the H-LAE group. We finally developed a sensitive UPLC-MRM-MS method for quantitative analysis of trans-Pet3R5G and its metabolites in plasma. These results showed that the liver and intestine play important roles in the metabolism of trans-Pet3R5G.