代谢
Tixocortol在红细胞内迅速被修饰,并且会立即通过首次通过肝脏代谢。Tixocortol的代谢物主要表现为形成磺酸和葡萄糖醛酸共轭物,这些共轭物随后被水解,形成中性类固醇。代谢转化包括3-酮和Δ4系统的还原,C-20羰基团的还原,C-11醇的氧化以及在C-17处侧链的断裂。C-21硫醇酯功能的特定代谢途径是其转化为甲硫基、甲磺酰基和甲磺酰基衍生物,以及C-21-S键的还原断裂,导致21-甲基结构。所有代谢物对糖皮质激素受体没有亲和力。这以及广泛的代谢解释了Tixocortol的独家局部活性。
Tixocortol is rapidly modified within red blood cells and it is immediately metabolized by a first-pass liver metabolism. The metabolites of tixocortol are mainly represented by the formation of sulfo- and glucurono-conjugates which are later hydrolyzed from the conjugate forming neutral steroids. The metabolic transformations are the reduction of the 3-keto and delta 4 system, reduction of the C-20 carbonyl group, oxidation of the C-11 alcohol and cleavage of the side chain at C-17. The specific metabolic pathways of the C-21 thiol ester function were its transformation into methylthio, methylsulfonyl and methylsulfonyl derivatives and reductive cleavage of the C-21-S bond leading to 21-methyl structures. None of the metabolites have affinity for glucocorticoid receptors. This and the extensive metabolism explains the exclusive local activities of tixocortol.
来源:DrugBank