甲酰四氢叶酸(化学上称为5-甲酰四氢叶酸)临床上广泛地用于抗肿瘤和抗微生物已30多年,但对其代谢作用了解甚少,近来的研究已确定丝氨酸羟甲基转移酶(SHMT)催化5-次甲基四氢叶酸水解为不可逆转的5-甲酰四氢叶酸,并证实此反应是体内5-甲酰四氢叶酸的来源。5-甲酰四氢叶酸不仅抑制SHMT和磷酸核糖氨基咪唑甲酰胺(AICAR)甲酰转移酶,还抑制一碳单位代谢的其它一些酶。这些研究证据已重新引起人们对测定该叶酸衍生物代谢作用的兴趣。 Leucovorin (chemically termed 5-leucovorin) has been used clinically for antitumor and antimicrobial activities for more than 30 years but little is known about its metabolism, and recent studies have established that serotonin Transferase (SHMT) catalyzes the hydrolysis of 5-methyltetrahydrofolic acid to irreversible 5-formyltetrahydrofolate and confirms that this reaction is the source of 5-formyltetrahydrofolate in vivo. 5-leucovorin not only inhibits SHMT and other phosphorylated ribosylimidazolecarboxamide (AICAR) formyltransferases, but also some of the enzymes that inhibit one carbon unit metabolism. The evidence from these studies has rekindled interest in determining the metabolic effects of this folate derivative.