Structure–Activity Relationship Studies on Oxazolo[3,4-<i>a</i>]pyrazine Derivatives Leading to the Discovery of a Novel Neuropeptide S Receptor Antagonist with Potent <i>In Vivo</i> Activity
urgent need for new effective therapeutic approaches. Potent NPSR antagonists in vitro have been discovered which, however, require further optimization of their in vivo pharmacological profile. This work describes a new series of NPSR antagonists of the oxazolo[3,4-a]pyrazine class. The guanidine derivative 16 exhibited nanomolar activity in vitro and 5-fold improved potency in vivo compared to SHA-68,
Neuropeptide S 通过与其 G 蛋白偶联受体(称为神经肽 S 受体 (NPSR))相互作用来调节重要的神经生物学功能,包括运动、焦虑和药物滥用。 NPSR 拮抗剂可潜在用于治疗药物滥用疾病,迫切需要新的有效治疗方法。体外有效的 NPSR 拮抗剂已被发现,然而,需要进一步优化其体内药理学特性。这项工作描述了恶唑并[3,4- a ]吡嗪类的一系列新 NPSR 拮抗剂。与该领域的参考药理学工具SHA-68相比,胍衍生物16在体外表现出纳摩尔级活性,在体内效力提高了 5 倍。化合物16可以被认为是研究 NPSergic 系统转化潜力的新工具。还进行了深入的分子建模研究,以获得对观察到的结构-活性关系的新见解,并提供配体/NPSR相互作用的更新模型。
Microwave-Assisted Synthesis of 2,5-Piperazinediones under Solvent-Free Conditions
A general, efficient and environmentally friendly procedure for the synthesis of 2,5-piperazinediones is described, involving the microwave irradiation of N-Boc dipeptide esters.
Highly efficient enantioselective synthesis of 1,3-disubstituted 2,5-diketopiperazine derivatives via microwave irradiation
作者:Si Yeon Han、Young-Dae Gong
DOI:10.1080/00397911.2019.1671983
日期:2019.12.17
Abstract Chiral 2,5-diketopiperazine (2,5-DKP) derivatives have a broad range of biological activities in the medicinal field. The synthetic protocols of 1,3-disubstituted 2,5-DKPs via base-catalyzed cyclization of chloroacetamide have been reported. However, there are several drawbacks, such as an overly long reaction time, low to moderate yield, and racemization of the products. The sequence modified
Synthesis and Structure of 1,4-Dipiperazino Benzenes: Chiral Terphenyl-type Peptide Helix Mimetics
作者:Prantik Maity、Burkhard König
DOI:10.1021/ol8002749
日期:2008.4.1
side-chain functionalities of peptidic alpha-helices. The synthesis of 1,4-dipiperazino benzenes, using stepwise transition metal-catalyzed N-arylation of chiral piperazines to a central benzene core is reported. The structure determination by X-ray crystallography reveals a geometrical arrangement of the hydrophobic side chains resembling the orientation of key i, i + 3, and i + 7 positions in a peptidic
Exploring the Structure−Activity Relationships of [1-(4-<i>tert</i>-Butyl-3‘-hydroxy)benzhydryl-4-benzylpiperazine] (SL-3111), A High-Affinity and Selective δ-Opioid Receptor Nonpeptide Agonist Ligand
作者:Josue Alfaro-Lopez、Toru Okayama、Keiko Hosohata、Peg Davis、Frank Porreca、Henry I. Yamamura、Victor J. Hruby
DOI:10.1021/jm990337f
日期:1999.12.1
SL-3111 [1-(4-tert-butyl-3'-hydroxy)benzhydryl-4-benzylpiperazine] is a de novo designed, high-affinity and selective nonpeptide peptidomimetic agonist of the delta-opioid receptor. In a previous report we had described the unique biological characteristics of this ligand and also a need for further structural evaluation(6). To pursue this, we have introduced a completely different heterocyclic template (2 and 3), which, based on molecular modeling studies, may present the required structural features to properly orient the pharmacophore groups. We also have made more subtle changes to the original piperazine scaffold (5 and 11). The biological activities of these compounds revealed an important participation of the scaffold in the ligand-receptor interaction. To further explore functional diversity on the scaffold, we have maintained the original piperazine ring and introduced four different functionalities at position 2 of the heterocyclic ring (15a-d; a = CH2-O-CH2-Ph; b = Me; c = CH2Ph; d = CH2OH). The biological activities observed for these compounds showed a very interesting trend in terms of the steric effects of the groups introduced at this position. A decrease of almost 2000-fold in affinity and potency at the delta-receptor was observed for 15c compared with 15b. This difference may be explained if we postulate that the bioactive conformation of these peptidomimetics is close to the minimal energy conformations calculated in our study. On the basis of these findings we have realized the importance of this position to further explore and simplify the structure of future generations of peptidomimetic ligands.