Mandelonitrile → Mandelonitrile
Reaction equation
[C:1]([OH:11])(=[O:10])[C@@H:2]([C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=1)[OH:3].[C:12](#[N:21])[CH:13]([C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1)[OH:14].[C:22]([NH2:32])(=O)[CH:23]([C:25]1[CH:30]=[CH:29][CH:28]=[CH:27][CH:26]=1)[OH:24]>>[C:1]([OH:11])(=[O:10])[C@@H:2]([C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=1)[OH:3].[C:12](#[N:21])[CH:13]([C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1)[OH:14].[C:22](#[N:32])[C@H:23]([C:25]1[CH:30]=[CH:29][CH:28]=[CH:27][CH:26]=1)[OH:24]Participants
Procedure
Yamamoto et al. (1991) tested various isolates (wildtype strains) with respect to their ability to convert mandelonitrile into (R)-(−)-mandelic acid. A. faecalis strain ATCC 8750 was found to have the highest level of activity and enantioselectivity to produce (R)-(−)-mandelic acid from racemic mandelonitrile (Yamamoto et al., 1991). In particular, the (R)-(−)-mandelic acid made of mandelonitrile by resting cells was present in a 100% enantiomeric excess. A. faecalis ATCC 8750 has an (R)-enantioselective nitrilase and an amidase used to process mandelonitrile and mandelamide, respectively. As (R)-(−)-mandelic acid was produced from racemic mandelonitrile in a yield of 91%, whereas no (S)-mandelonitrile was left, the (S)-(−)-mandelonitrile remaining in the reaction is spontaneously racemised because of the chemical equilibrium of the (R)- and the (S)-isomer of mandelonitrile on the one hand and benzaldehyde/HCN on the other hand. Consequently, almost all the mandelonitrile is consumed and converted to (R)-(−)-mandelic acid. It is noted that, according to Yamamoto et al. (1991), the A. faecalis cells employed for production of (R)-mandelic acid require specifically optimized culture conditions.
Sources & evidence
- ORD record
- ord-2783a0f4de564691b5c7750ee621255b
- Source dataset
- uspto-grants-2015_02
- Patent number
- US08945887B2
Reaction notes
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