Medicinal chemistry driven approaches toward novel and selective serotonin 5-HT6 receptor ligands
ABSTRACT Based on a medicinal chemistry guided hypothetical pharmacophore model, novel series of indolyl sulfonamides have been designed and prepared as selective and high-affinity serotonin 5-HT(6) receptor ligands. Furthermore, based on a screening approach of a discovery library, a series of benzoxazinepiperidinyl sulfonamides were identified as selective 5-HT(6) ligands. Many of the compounds described in this paper possess excellent affinities, displaying pK(i) values greater than 8 (some even >9) and high selectivities against a wide range (>50) of other CNS relevant receptors. First, structure-affinity relationships of these ligands are discussed. In terms of functionality, high-affinity antagonists, as well as agonists and even partial agonists, were prepared. Compounds 19c and 19g represent the highest-affinity 5-HT(6) agonists ever reported in the literature. These valuable tool compounds should allow for the detailed study of the role of the 5-HT(6) receptor in relevant animal models of disorders such as cognition deficits, depression, anxiety, or obesity.
SourceAvailable from: Dorit Moradov[Show abstract] [Hide abstract]
ABSTRACT: A prolonged increase in pro-inflammatory cytokines, TNF-α and IL-6 occurs in inflammatory diseases. Although existing therapies like steroids and TNF-α antagonists are effective they may cause serious adverse effects. We describe the preparation and evaluation for anti-inflammatory activity of 11 novel derivatives of indoline carbamates with a propionic ester, 2-aminoethyl, 3-aminopropyl 2-(dimethylamino)ethyl or 3-(dimethylamino)propyl group in positions 3 or 1. Compounds 25, 26 and 29 were previously shown to inhibit acetylcholinesterase with IC50s ranging from 0.4 to 55μM and to prevent cytotoxicity induced by reactive oxygen species in a concentration range of 100pM-1μM. Compounds 25, 26, 29, 9, 10, 17 and 18, reduced NO, TNF-α and IL-6 at concentrations of 1-10pM in LPS-activated RAW-264.7 and mouse peritoneal macrophages. The reduction in cytokines by compound 25 was associated with an increase in IκBα degradation and a decrease in the phosphorylation of p38 but not that of ERK. Conclusion: Indoline derivatives substituted at position 3 with chains carrying ester or amino groups may have potential for the treatment of chronic inflammatory and neurodegenerative diseases.Bioorganic & medicinal chemistry letters 04/2014; DOI:10.1016/j.bmcl.2014.03.081 · 2.65 Impact Factor
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ABSTRACT: The central 5-hydroxytryptamine (5-HT; serotonin) system is well established as an important regulator of appetite and continues to remain a focus of obesity research. While much emphasis has focussed on the 5-HT2C receptor (5-HT2CR) in 5-HT's anorectic effect, pharmacological manipulation of the 5-HT6 receptor (5-HT6R) also reduces appetite and body weight and may be amenable to obesity treatment. However, the neurological circuits that underlie 5-HT6R-induced hypophagia remain to be identified. Using c-fos immunoreactivity (FOS-IR) as a marker of neuronal activation, here we mapped the neuroanatomical targets activated by an anorectic dose of the 5-HT6R antagonist SB-399885 throughout the brain. Furthermore, we quantified SB-399855 activated cells within brain appetitive nuclei, the hypothalamus, dorsal raphe nucleus (DRN) and nucleus of the solitary tract (NTS). Our results reveal that 5-HT6R antagonist-induced hypophagia is associated with significantly increased neuronal activation in two nuclei with an established role in the central control of appetite, the paraventricular nucleus of the hypothalamus (PVH) and the NTS. In contrast, no changes in FOS-IR were observed between treatment groups within other hypothalamic nuclei or DRN. The data presented here provide a first insight into the neural circuitry underlying 5-HT6R antagonist-induced appetite suppression and highlight the PVH and NTS in the coordination of 5-HT6R hypophagia.Behavioural brain research 02/2014; 266. DOI:10.1016/j.bbr.2014.02.018 · 3.22 Impact Factor
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ABSTRACT: High-throughput screening of a specific set (focused library) of heterocyclic compounds containing an alkylsulfonyl moiety (a total of 2827 compounds from 78 combinatorial libraries) was performed in order to discover highly effective 5-HT6 receptor antagonists. The screening identified several compounds that exhibited pronounced inhibiting properties for 5-HT6 receptors that enabled them to be used to develop new highly effective drugs for treating central nervous system disturbances. The structures of most antagonists corresponded to the PhM2 pharmacophore model, which confirmed its potential in the search for effective 5-HT6 receptor antagonists. It was established that the structure of the substituent introduced in the vicinity of the sulfonyl moiety in the PhM2 ligands could affect their pharmacological activity, including the ability to block serotonin-induced 5-HT6 receptor-mediated cell responses. In particular, bulky electron-donating substituents decreased the activity whereas a methylamino group increased statistically significantly the 5-HT6 antagonistic activity. Based on these findings, a new pharmacophore model for 5-HT6 antagonists, PhM3, was proposed. It was shown that compounds from the combinatorial libraries with a sulfonyl moiety separated from the heterocyclic and/or aromatic moiety by one (or more) methylenes and heterocyclic compounds containing an alkylsulfonyl moiety or endocyclic sulfonyl, (5-aryl-sulfonyl-3H-[1,2,3]triazol-4-yl)amines, and azoles substituted simultaneously by arylsulfonyl and alkylsulfonyl moieties all had low hit rates and were not promising for discovery of new 5-HT6 receptor antagonists.Pharmaceutical Chemistry Journal 08/2012; 46(5). DOI:10.1007/s11094-012-0779-z · 0.30 Impact Factor