Table 3. Application of ERs in the Synthesis of Isopulegon, Isopulegol, Dihydroperillaldehyde and Dihydro-β-ionone.

entry	whole cell or ene reductase	performance	reference
1	IPR from Mentha piperita	cis-isopulegone, 91% yield, 19% de	(102)
		(R)-pulegone, 28% yield, >99% ee
2	YqjM + AacSHC-I261A from Alicyclobacillus acidocaldarius	(−)-iso-isopulegol, 10.8% yield	(103)
3	OYE1 → OYE1-W116	(1S,4S)-DHPA, 42% conv., 79% de	(13)
		→
		(1R,4R)-DHPA, 20% conv., 52% de
4	DBR1 from Artemisia annua	dihydro-β-ionone, 93.8% conv.	(110)
5	PhCCD1 from Petunia hybrid + DBR1	dihydro-β-ionone, 85.8% conv.	(112)