Identification of Neuropeptide S Antagonists: Structure–Activity Relationship Studies, X‑ray Crystallography, and in Vivo Evaluation

Modulation of the neuropeptide S (NPS) system has been linked to a variety of CNS disorders such as panic disorder, anxiety, sleeping disorders, asthma, obesity, PTSD, and substance abuse. In this study, a series of diphenyltetrahydro-1<i>H</i>-oxazolo­[3,4-α]­pyrazin-3­(5<i>H</i>)-ones were synthesized and evaluated for antagonist activity at the neuropeptide S receptor. The absolute configuration was determined by chiral resolution of the key synthetic intermediate, followed by analysis of one of the individual enantiomers by X-ray crystallography. The <i>R</i> isomer was then converted to a biologically active compound (<b>34</b>) that had a <i>K</i>_e of 36 nM. The most potent compound displayed enhanced aqueous solubility compared with the prototypical antagonist SHA-68 and demonstrated favorable pharmacokinetic properties for behavioral assessment. In vivo analysis in mice indicated a significant blockade of NPS induced locomotor activity at an ip dose of 50 mg/kg. This suggests that analogs having improved drug-like properties will facilitate more detailed studies of the neuropeptide S receptor system

The nature of cartilage stippling in chondrodysplasia punctata: histopathological study of Conradi-Hünermann syndrome.

The chondrodysplasia punctatas (CDP) are a group of genetic diseases presenting with the common hallmark of epiphyseal calcific deposits. A 21.3 week female fetus with a clinical and molecular diagnosis of X-linked dominant CDP (CDPX2 or Conradi-Hunermann syndrome) has been investigated with particular attention to the morphology of the calcific deposits (stipplings). A variable combination of normal endochondral ossification centers, calcific deposits, and a mixture of these two were observed in the lumbar spine. The calcific deposits were characterized by a growing phase, corresponding to the expansion of calcification, a steady phase, and a resorbing/remodeling phase, when calcification was progressively reduced through different biological mechanisms. The pathological mechanism of cartilage matrix calcification seemed to influence the morphology and the distribution pattern of vessels inside the epiphysis. These findings fit well with the radiographic observations of progressive regression of stippling with advancing age of the child and also give a morphological correlation

Design and Synthesis of 4‑Heteroaryl 1,2,3,4-Tetrahydroisoquinolines as Triple Reuptake Inhibitors

A series of 4-bicyclic heteroaryl 1,2,3,4-tetrahydroisoquinoline inhibitors of the serotonin transporter (SERT), norepinephrine transporter (NET), and dopamine transporter (DAT) was discovered. The synthesis and structure–activity relationship (SAR) of these triple reuptake inhibitors (TRIs) will be discussed. Compound <b>10i</b> (AMR-2), a very potent inhibitor of SERT, NET, and DAT, showed efficacy in the rat forced-swim and mouse tail suspension models with minimum effective doses of 0.3 and 1 mg/kg (<i>po</i>), respectively. At efficacious doses in these assays, <b>10i</b> exhibited substantial occupancy levels at the three transporters in both rat and mouse brain. The study of the metabolism of <b>10i</b> revealed the formation of a significant active metabolite, compound <b>13</b>