A series of beta-aminoamides bearing triazolopiperazines have been discovered as potent, selective, and orally active dipeptidyl peptidase IV (DPP-4) inhibitors by extensive structure-activity relationship (SAR) studies around the triazolopiperazine moiety. Among these, compound 34b with excellent in vitro potency (IC50 = 4.3 nM) against DPP-4, high selectivity over other enzymes, and good pharmacokinetic profiles exhibited pronounced in vivo efficacy in an oral glucose tolerance test (OGTT) in lean mice. On the basis of these properties, compound 34b has been profiled in detail. Further refinement of the triazolopiperazines resulted in the discovery of a series of extremely potent compounds with subnanomolar activity against DPP-4 (42b- 49b), that is, 4-fluorobenzyl-substituted compound 46b, which is notable for its superior potency (IC50 = 0.18 nM). X-ray crystal structure determination of compounds 34b and 46b in complex with DPP-4 enzyme revealed that (R)-stereochemistry at the 8-position of triazolopiperazines is strongly preferred over (S) with respect to DPP-4 inhibition.

中文翻译：

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发现了有效的和选择性的二肽基肽酶IV抑制剂，该抑制剂衍生自带有取代的三唑并哌嗪的β-氨基酰胺。

通过围绕三唑并哌嗪部分的广泛结构-活性关系（SAR）研究，已发现一系列带有三唑并哌嗪的β-氨基酰胺为有效，选择性和口服活性的二肽基肽酶IV（DPP-4）抑制剂。在这些化合物中，对DPP-4具有优异的体外效力（IC50 = 4.3 nM），对其他酶的选择性高以及良好的药代动力学特征的化合物34b在瘦小鼠的口服葡萄糖耐量试验（OGTT）中显示出明显的体内功效。基于这些性质，化合物34b已被详细剖析。对三唑并哌嗪的进一步改良导致发现了一系列对DPP-4（42b-49b）具有亚纳摩尔活性的极其有效的化合物，即4-氟苄基取代的化合物46b，以其优越的效力而著称（IC50 = 0。18 nM）。与DPP-4酶复合的化合物34b和46b的X射线晶体结构测定表明，就DPP-4抑制而言，三唑并哌嗪在8位的（R）-立体化学优于（S）。