Membrane Separations for Green Chemistry - Process Intensification for Green Chemistry - page 332

Table 12.11 Examples of differences between (S)-enantiomers and (R)-enantiomers (adapted
from [67]).

Component Enantiomer differences

Dopa (S)-enantiomer: anti-Parkinson

(R)-enantiomer: serious side effects

Penicillamine (S)-enantiomer: antiarthritic

(R)-enantiomer: mutagen

Tahlidomide (S)-enantiomer: teratogen

(R)-enantiomer: sedative

Ketamine (S)-enantiomer: anaesthetic

(R)-enantiomer: hallucinogen

Ethambutol (S)-enantiomer: (S,S)-tuberculostatic

(R)-enantiomer: (R,R)-; blindness

Novrad (S)-enantiomer: (2R, 3S); analgesic

(R)-enantiomer: (2S, 3R)-(-); antitussive

Indacrinone (S)-enantiomer: uricosuric

(R)-enantiomer: diuretic

Plactobutrazol (S)-enantiomer: (2R, 3S); plant growth regulation

(R)-enantiomer: (2R, 3S); fungicide

Asparagine (S)-enantiomer: bitter

(R)-enantiomer: sweet

Aspartame (S)-enantiomer: (S,S); sweet

(R)-enantiomer: (R,R); bitter

Limonene (S)-enantiomer: lemon odour

(R)-enantiomer: orange odour

Metadone

L -methadone: antiallodynic
D -methadone: inactive

Citalopram (S)-citalopram is over 100-fold more potent an inhibitor of the serotonin

reuptake transporter than (R)-citalopram

Verapamil The bioavailability of (R)-verapamil is more than double that of

(S)-verapamil, due to reduced hepatic first-pass metabolism

Ibuprofen The (S)-enantiomer is over 100-fold more potent as an inhibitor of cyclo-

oxygenase than (R)-ibuprofen

Table 12.12 Technologies actually available for the production enantiomers.

Physical methods Classical resolution (diasteromeric crystallization)

Membrane separation
Chromatography
Capillary electrophoresis
Sensors
Liquid-liquid extraction

Asymmetric synthesis Using chemical and biochemical catalysts

Biological methods Biotransformation-based processes (e.g. biocatalytic membrane

reactor)