Department of Pharmacy, The First Affiliated Hospital of Kangda College of Nanjing Medical University/The First People's Hospital of Lianyungang, Lianyungang, P. R. China.
Jiangsu Wanbang Pharmaceutical Technology Co. Ltd, P. R. China.
J Sep Sci. 2022 Aug;45(15):2914-2923. doi: 10.1002/jssc.202200250. Epub 2022 Jun 26.
Dihydromethysticin, a natural component from Piper methysticum Forst, has been reported to display pharmacological effects in mental disorders and some malignant tumors. However, the metabolism of this component remained unknown. The goal of this work was conducted to discover the metabolic profiles of dihydromethysticin. The in vitro incubation was performed by incubating dihydromethysticin with rat, monkey, and human liver microsomes and hepatocytes. An analytical assay of ultra-high performance liquid chromatography combined with Orbitrap high-resolution mass spectrometry was utilized to detect and identify the metabolites. With high resolution mass spectrometric determination, the accurate mass, elemental composition, and product ions of the metabolites were determined, which enabled structural characterization to become easy. Under the present conditions, four phase-I metabolites, as well as six phase-II metabolites, were detected and their tentative structures were characterized by mass spectra. M4 was found as the most abundant metabolite both in liver microsomes and hepatocytes. Cytochrome P450 1A2, 2C9, and 3A4 contributed to the formation of this metabolite by using human recombinant P450 enzymes. M4 can be oxidized into reactive ortho-quinone intermediate followed by conjugating with glutathione. M4 was also subject to glucuronidation (M1 and M2) and methylation (M5). Demethylenation, oxidation, hydroxylation, glucuronidation, glutathionylation, and methylation were the primary metabolic pathways of dihydromethysticin. This study provides in vitro metabolism data of dihydromethysticin, which is indispensable for understanding the disposition of this compound.
二氢醉椒素是一种来自胡椒科醉椒的天然成分，据报道具有治疗精神障碍和某些恶性肿瘤的药理学作用。然而，其代谢途径仍不清楚。本研究旨在发现二氢醉椒素的代谢产物。采用大鼠、猴和人肝微粒体和肝细胞进行体外孵育，通过超高效液相色谱-轨道阱高分辨质谱联用分析方法检测和鉴定代谢产物。利用高分辨质谱测定，确定了代谢产物的精确质量、元素组成和产物离子，使结构特征易于确定。在目前的条件下，在肝微粒体和肝细胞中检测到了 4 种 I 相代谢产物和 6 种 II 相代谢产物，并通过质谱对其暂定结构进行了表征。M4 是在肝微粒体和肝细胞中含量最丰富的代谢产物。使用人重组 P450 酶发现细胞色素 P450 1A2、2C9 和 3A4 有助于形成该代谢产物。M4 可以氧化成活性邻醌中间产物，然后与谷胱甘肽结合。M4 还可以发生葡萄糖醛酸化（M1 和 M2）和甲基化（M5）。脱甲基化、氧化、羟化、葡萄糖醛酸化、谷胱甘肽化和甲基化是二氢醉椒素的主要代谢途径。本研究提供了二氢醉椒素的体外代谢数据，这对于了解该化合物的处置至关重要。
