All of the selective COX-2 inhibitors described to date inhibit the isoform by binding tightly but noncovalently at the substrate binding site. Recently, we reported the first account of selective covalent modification of COX-2 by a novel inactivator, 2-acetoxyphenyl hept-2-ynyl sulfide (70) (Science 1998, 280, 1268-1270). Compound 70 selectively inactivates COX-2 by acetylating the same serine residue that aspirin acetylates. This paper describes the extensive structure-activity relationship (SAR) studies on the initial lead compound 2-acetoxyphenyl methyl sulfide (36) that led to the discovery of 70. Extension of the S-alkyl chain in 36 with higher alkyl homologues led to significant increases in inhibitory potency. The heptyl chain in 2-acetoxyphenyl heptyl sulfide (46) was optimum for COX-2 inhibitory potency, and introduction of a triple bond in the heptyl chain (compound 70) led to further increments in potency and selectivity. The alkynyl analogues were more potent and selective COX-2 inhibitors than the corresponding alkyl homologues. Sulfides were more potent and selective COX-2 inhibitors than the corresponding sulfoxides or sulfones or other heteroatom-containing compounds. In addition to inhibiting purified COX-2, 36, 46, and 70 also inhibited COX-2 activity in murine macrophages. Analogue 36 which displayed moderate potency and selectivity against purified human COX-2 was a potent inhibitor of COX-2 activity in the mouse macrophages. Tryptic digestion and peptide mapping of COX-2 reacted with [1-14C-acetyl]-36 indicated that selective COX-2 inhibition by 36 also resulted in the acetylation of Ser516. That COX-2 inhibition by aspirin resulted from the acetylation of Ser516 was confirmed by tryptic digestion and peptide mapping of COX-2 labeled with [1-14C-acetyl]salicyclic acid. The efficacy of the sulfides in inhibiting COX-2 activity in inflammatory cells, our recent results on the selectivity of 70 in attenuating growth of COX-2-expressing colon cancer cells, and its selectivity for inhibition of COX-2 over COX-1 in vivo indicate that this novel class of covalent modifiers may serve as potential therapeutic agents in inflammatory and proliferative disorders.

中文翻译：

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通过2-乙酰氧基苯基烷基硫醚（一种新型的选择性COX-2灭活剂）对环氧合酶2（COX-2）进行共价修饰。

迄今为止描述的所有选择性COX-2抑制剂都通过与底物结合位点紧密但非共价结合来抑制同工型。最近，我们首次报道了一种新型灭活剂2-乙酰氧基苯基庚-2-炔基硫醚对COX-2的选择性共价修饰（70）（Science 1998，280，1268-1270）。化合物70通过乙酰化阿司匹林乙酰化的相同丝氨酸残基来选择性灭活COX-2。本文描述了对最初的铅化合物2-乙酰氧基苯基甲基硫化物（36）的广泛的构效关系（SAR）的研究，该研究导致了70的发现。S-烷基链在36个具有较高烷基同系物的情况下延伸导致显着的增加抑制力。2-乙酰氧基苯基庚基硫醚中的庚基链（46）最适合抑制COX-2，在庚基链（化合物70）中引入三键导致效力和选择性进一步提高。炔基类似物比相应的烷基同系物更有效和更具选择性。与相应的亚砜或砜或其他含杂原子的化合物相比，硫化物是更有效和更具选择性的COX-2抑制剂。除抑制纯化的COX-2外，36，46和70还抑制鼠巨噬细胞中的COX-2活性。显示出对纯化的人COX-2具有中等效力和选择性的类似物36是小鼠巨噬细胞中COX-2活性的有效抑制剂。与[1-14C-乙酰基] -36反应的COX-2的胰蛋白酶消化和肽图分析表明，36的选择性COX-2抑制作用还导致Ser516的乙酰化。通过胰蛋白酶消化和用[1-14C-乙酰基]水杨酸标记的COX-2的肽图分析，证实了阿司匹林对Ser516乙酰化产生的COX-2抑制作用。硫化物在炎性细胞中抑制COX-2活性的功效，我们最近的研究结果显示70在抑制表达COX-2的结肠癌细胞生长中的选择性以及在抑制COX-2的过程中对COX-1的抑制作用体内表明，这种新型的共价修饰剂可以作为炎症和增生性疾病中的潜在治疗剂。