Naslov
Influence of the Acyl Moiety on the Hydrolysis of Quinuclidinium Esters Catalyzed by Butyrylcholinesterase

Autori
Primožič, Ines ; Tomić, Srđanka

Izvornik
Croatica chemica acta (0011-1643) 84 (2011), 2; 245-249

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
esters of quinuclidin-3-ol/ enzymic resolution/ butyrylcholinesterase/ hydrolysis kinetics/ inhibition constants/

Sažetak
Eight chiral esters of quinuclidin-3-ol and butyric, acetic, pivalic and benzoic acid were synthesized as well as their racemic and chiral, quaternary N-benzyl derivatives. All racemic and chiral quaternary compounds were studied as substrates and/or inhibitors of horse serum butyrylcholinesterase (BChE). The best substrate for the enzyme was (R)-N-benzyl butyrate. The rates of hydrolysis decreased in order (R)-butyrate >> (R)-acetate (7-fold slower) > (R)-pivalate (8-fold slower) > (R)-benzoate (9-fold slower reaction), while (S)-N-benzyl esters were much poorer substrates (320 (butyrate) - 4360-fold slower (pivalate) than the appropriate (R)-enantiomer). For all (S)-N-benzyl esters excluding (S)-N-benzyl acetate inhibition constants were determined (Ka=3.3-60 µM). The hydrolysis of racemic mixtures of N-benzyl esters proceeded 1.4 (for acetate) - 5.1 (for benzoate) times slower than that of pure (R)-enantiomers of the corresponding concentrations due to the inhibition with (S)-enantiomers. Change of the acyl moiety of the substrate effected both activity and stereoselectivity of the BChE.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA