Table 1.

Reaction optimization and control experiments^a.

Entry	Deviation from standard conditions	Yield (%)b	D-incorporation (%)d
1	Standard conditions	99 (75c)	93
2	Free FAD	0	–
3	No CvFAP	0	–
4	No light	0	–
5	No DMSO	17	93
6	CH3CN instead of DMSO	96	95
7	H2O instead of D2O	99	0
8	Air	99	93

^aReaction conditions: Substrate (0.40 mmol), crude enzyme powder (containing CvFAP about 20 mg), D₂O (4 mL), DMSO (1 mL), 450 nm LED, 20 °C, 12 h.

^bYields were determined by GC.

^cIsolated yield.

^dD-incorporation are determined by ¹H NMR or HRMS.