ACE inhibitors의 합성과 억제효과에 관한 연구

Abstract

Angiotensin converting enzyme (ACE)와 공유결합하여 효소활성 억제효과를 나타내는 mechanism (mechanism-based inactivation, affinity labeling agent의 ACE 억제제로 epoxide류와 α,β-unsaturated acylamino acid유도체를 합성하였다. 즉, 효소의 active site 중의 S_(1') pocket과 강한 hydrophobic interaction을 할 수 있는 aromatic ring을 도입한 epoxide유도체, dipeptide를 이용하여 amide의 α위치 methyl기를 도입하여 S_(1') pocket과 강한 hydrophobic interaction을 할 수 있는 epoxide유도체 및 affinity labeling agent로 기대되는 α,β-unsaturated acyl amino acid유도체와 amide결합의 α위치에 leaving group(Br)을 도입한 유도체를 합성하였다. 합성된 화합물 중 α,β-unsaturated acyl amino acid유도체가 ACE 저해효과를 나타내었는데, 이는 carbonyl group이 Zn^(2+)와 배위결합한 다음 활성부위내에 있는 glutamic acid의 carboxylate가 nucleophile로 작용하여 Michael addition이 일어나 저해제가 효소에 결합되기 때문인 것으로 추정하였다.;Mechanism-based inactivators and affinity labeling agents inhibit enzyme activity irreversibly through the covalent bond formation with enzyme. In this study, the following three-type derivatives were synthesized as potential irreversible ACE(angiotensin converting enzyme) inhibitors: epoxide derivatives, α,β-unsaturated acylamino acid derivatives and derivatives with the leaving group(Br). The various epoxide derivatives with phenyl substitution were designed to have the strong hydrophobic interaction with S_(1) pocket on the active site of enzyme, while epoxide group acts as electrophilic site for covalent binding. The α,β-unsaturated acylamino acid derivatives were also designed to make covalent bond with the enzyme by Michael addition which was triggered by the coordinate bond of carbonyl group with zinc ion and the nucleophilic action of glutamic acid in the enzyme. The dipeptide analogues were designed to fix the stereochemistry of methyl group (α position to the carbonyl) as S using natural L-amino acids. The compounds with bromine on a position of amide bond were also synthesized to make affinity labeling. Among the synthesized compounds, epoxide derivatives showed very week ACE inhibition, but α,β-unsaturated acylamino acid derivatives showed higher ACE inhibition (IC_(50) of compound 7 is 0.16 mM).