MqnD
catalyzes the conversion of cyclic dehypoxanthine futalosine
(6) to 5,8-dihydroxy-2-naphthoic acid (7) and an uncharacterized product. This study describes a chemoenzymatic
synthesis of 6. 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 (5) that was converted to 6 by
an ipso substitution mechanism. This synthetic route enabled the synthesis
of 6 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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.