Biosynthesis and structure assignment of a hydroxylated metabolite of the orexin-1 receptor antagonist JNJ-61393215

JNJ-61393215, a deuterated compound, is a selective OX1R antagonist. In both preclinical and clinical studies, a hydroxylated metabolite designated M54 was observed to be the most abundant metabolite in plasma. Screening of Hypha PolyCYPs®⁺ kit revealed PolyCYP 152 was the most proficient at producing M54 from JNJ-61393215 and subsequent scale up with PolyCYP 152 provided small but sufficient quantities of M54 for initial structure elucidation by NMR analyses. A microbial biosynthesis, using a Streptomyces strain from which PolyCYP 152 was genetically derived, provided gram quantities of M54. It allowed chemical epimerization of the chiral hydroxylated carbon of M54 and unequivocally established the metabolite's absolute stereo-configuration. The biotransformation provided remarkably efficient methodologies for quick synthesis of the metabolite M54 with stereoselective hydroxylation on the deuterated unique 2-aza-[2.2.1]-bicycle core structure, for which structure assignment via classical synthesis of speculative structures would be challenging and resource-intensive. Moreover, the microbial biosynthesis provided M54 with high purity for ongoing preclinical studies.