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The eutomer is the enantiomer having the desired pharmacological activity, [4] e.g., as an active ingredient in a drug. The distomer , on the other hand, is the enantiomer of the eutomer which may have undesired bioactivity or may be bio-inert.
An example of such an enantiomer is the sedative thalidomide, which was sold in a number of countries around the world from 1957 until 1961. It was withdrawn from the market when it was found to cause birth defects. One enantiomer caused the desirable sedative effects, while the other, unavoidably [23] present in equal quantities, caused birth ...
An enantiopure drug is a pharmaceutical that is available in one specific enantiomeric form. Most biological molecules (proteins, sugars, etc.) are present in only one of many chiral forms, so different enantiomers of a chiral drug molecule bind differently (or not at all) to target receptors.
In chemistry, racemization is a conversion, by heat or by chemical reaction, of an optically active compound into a racemic (optically inactive) form. This creates a 1:1 molar ratio of enantiomers and is referred to as a racemic mixture (i.e. contain equal amount of (+) and (−) forms).
In some cases, the less therapeutically active enantiomer can cause side effects. For example, ( S -naproxen is an analgesic but the ( R -isomer causes renal problems. [ 31 ] In such situations where one of the enantiomers of a racemic drug is active and the other partner has undesirable or toxic effect one may switch from racemate to a single ...
The drug was withdrawn from world market when it became evident that the use in pregnancy causes phocomelia (clinical conditions where babies are born with deformed hand and limbs). Later in late 1970s studies indicated that the (R)- enantiomer is an effective sedative, the (S)-enantiomer harbors teratogenic effect and causes fetal abnormalities.
Pseudouridine is the most abundant RNA modification in cellular RNA [2] and one of over 100 chemically distinct modifications that may affect translation or other functions of RNA. Pseudouridine is the C5- glycoside isomer of uridine that contains a C-C bond between C1 of the ribose sugar and C5 of uracil , rather than usual C1-N1 bond found in ...
in what is known as the Horeau effect [3] the relationship between mole based ee and optical rotation based ee can be non-linear i.d. in the succinic acid example the optical activity at 50% ee is lower than expected. the specific rotation of enantiopure 1-phenylethanol can be enhanced by the addition of achiral acetophenone as an impurity. [4]