ACE inhibitor로서의 epoxide류 합성과 억제효과에 관한 연구

Abstract

2-Benzyl-3, 4-epoxybutanoic acid (BEBA)가 carboxypeptidase A에 공유결합하여 pseudomechanism based inactivator로 작용한다는 결과 (김동한, J. Am.Chem. Soc., 113, 3200, 1991)를 토대로 하여 구조가 유사한 epoxide류를 angiotensin converting enzyme(ACE)과 공유결합 할 수 있는 비가역적 mechanism의 저해제 후보물질로서 개발하였다. ACE는 carboxy-peptidase A와는 달리 2개의 아미노산 단위를 끊어주므로 BEBA보다 amide결합이 하나 더 많은 epoxide류 10여종을 합성하였다. 합성경로는 여러가지 불포화 지방산을 출발물질로 하여 acid chloride로 변환, phenylalanine등과 결합 및 oxone을 이용한 epoxidation이었다. 합성된 화합물의 ACE에 대한 IC_(50)를 측정하였을때, 그 값은 0.6-5.5mM이었다. IC_(50)의 측정 결과로 부터 epoxide기의 존재, amide기에서 epoxide기의 거리 및 carbonyl기의 α위치 탄소에 붙은 methyl기 등이 약효에 중요한 역할을 하는 것을 알 수 있었다.;Renin-angiotensin system is one of the most important control mechanisms for blood pressure. Therefore angiotensin-converting enzyme(ACE)inhibitors such as captopril are widely used as mild antihypertensive agents. In this study, new ACE inhibitors with a different inhibition mechanism are synthesized and their activity was investigated. Carboxypeptidase A served as a prototypic enzyme for ACE. From the resemblence to carboxypeptidase A, the binding site of ACE was hypothesized as zinc ion, carboxylate-binding group and a group that binds the C-terminal amino acid side chain. It was reported that 2-benzyl-3,4-epoxybutanic acid(BEBA) was pseudomechanism-based inactivator against carboxypeptidase A and formed a covalent linkage with the carboxylate of Glu. in carboxypeptidase A. Therefore a series of epoxides which has a more amide bond than BEBA were synthesized. The synthetic route for the epoxide derivatives was as follows. The corresponding unsaturated fatty acids were frequently converted into their amides via the acid chlorides. And the final products, epoxides, were formed when these amides were reacted with dimethyl-dioxirane which was a new class of powerful oxidants. ACE inhibition was evaluated in vitro against rabbit lung ACE using hippuryl-histidyl-leucine as substrate, and IC_(50) value for inhibition of ACE by epoxide derivatives was 0.6-5.5mM range. The structure-activity relationship was concluded that (1) epoxide group is necessary, (2) the distance between a amide group and a epoxide group is not important, and (3) the α-methyl group of a carbonyl group is a significant pharmacophore.