Figure 1.

Proposed biocatalytic route to Molnupiravir. (a) Wild-type cytidine deaminase (CD) catalyzes the hydrolysis of 2 to 3. (b) The active site of CD with uridine bound (PDB code: 1AF2). The Zn²⁺ ion is shown in gray. His102, Cys129, Cys132, and catalytic Glu104 are shown as atom-colored sticks with blue carbons. Uridine ligand is shown as atom-colored sticks with black carbons. (c) Proposed synthetic route to Molnupiravir 1. 2 is converted to 4 by an engineered CD followed by acylation using Novozym 435.^3,4