Department of Chemistry, Texas A&M University, College Station, Texas 77842, United States.
Biochemistry. 2021 Jun 29;60(25):1947-1951. doi: 10.1021/acs.biochem.1c00257. Epub 2021 Jun 18.
MqnD catalyzes the conversion of cyclic dehypoxanthine futalosine () to 5,8-dihydroxy-2-naphthoic acid () and an uncharacterized product. This study describes a chemoenzymatic synthesis of . This synthesis achieved a 2-fold yield enhancement by using titanium(III) citrate as the reducing agent and another 5-fold yield enhancement using a fluorinated analogue of dehypoxanthine futalosine () that was converted to by an ipso substitution mechanism. This synthetic route enabled the synthesis of in sufficient quantity to identify the second reaction product and to determine that the MqnD-catalyzed reaction proceeds by a hemiacetal ring opening-tautomerization-retroaldol sequence.
MqnD 催化环去黄嘌呤呋咱核苷（）转化为 5,8-二羟基-2-萘甲酸（）和一种未鉴定的产物。本研究描述了一种化学酶促合成的方法。该合成方法通过使用柠檬酸钛（III）作为还原剂，将产率提高了 2 倍，并用去黄嘌呤呋咱核苷（）的氟化类似物作为另一种反应物，将产率提高了 5 倍，该类似物通过邻位取代机制转化为。这条合成路线使足以合成第二个反应产物，从而确定 MqnD 催化的反应通过半缩醛开环-互变异构-逆羟醛缩合序列进行。
