Inhibition of (+)-Aristolochene Synthase with Iminium Salts Resembling Eudesmane Cation
摘要:
Trigonal iminium halides of (4aS,7S)-1,4a-dimethyl- and (4aS,7S)-4a-methyl-7-(prop-1-en-2-yl)-2,3,4,4a,5,6,7,8-octahydroquinolinium ions, aimed to mimic transition states associated with the aristolochene synthase-catalyzed cyclization of (-)-germacrene A to eudesmane cation, were evaluated under standard kinetic steady-state conditions. In the presence of inorganic diphosphate, these analogues were shown to competitively inhibit the enzyme, suggesting a stabilizing role for the diphosphate leaving group in this apparently endothermic transformation.
Intermediacy of Eudesmane Cation during Catalysis by Aristolochene Synthase
作者:Juan A. Faraldos、Benson Kariuki、Rudolf K. Allemann
DOI:10.1021/jo902397v
日期:2010.2.19
PPi to enhance the binding affinity of 6 for PR-AS could be interpreted against an eudesmyl cation/diphosphate anion pair mechanism as the enzymatic strategy to stabilize the highly reactive eudesmane cation 4. In addition, these observations seem to rule out simple favorable electrostatic and/or hydrogen bonding interactions between the activesite anchored diphosphate ion and the ammoniumion 6 as
Inhibition of (+)-Aristolochene Synthase with Iminium Salts Resembling Eudesmane Cation
作者:Juan A. Faraldos、Rudolf K. Allemann
DOI:10.1021/ol2000843
日期:2011.3.4
Trigonal iminium halides of (4aS,7S)-1,4a-dimethyl- and (4aS,7S)-4a-methyl-7-(prop-1-en-2-yl)-2,3,4,4a,5,6,7,8-octahydroquinolinium ions, aimed to mimic transition states associated with the aristolochene synthase-catalyzed cyclization of (-)-germacrene A to eudesmane cation, were evaluated under standard kinetic steady-state conditions. In the presence of inorganic diphosphate, these analogues were shown to competitively inhibit the enzyme, suggesting a stabilizing role for the diphosphate leaving group in this apparently endothermic transformation.