(1S,4S)-4-[(4-hydroxyphenyl)methyl]-2,5-diazaspiro[bicyclo[3.2.1]octane-6,1'-cyclohexane]-2',5'-dien-4'-one + 2 NADPH + 2 H(+) = (1S,4S)-4-[(4-hydroxyphenyl)methyl]-2,5-diazaspiro[bicyclo[3.2.1]octane-6,1'-cyclohexan]-4'-one + 2 NADP(+) — reaction