Argyrios G. Arvanitis

Synthesis, Structure—Activity Relationships, and In Vivo Evaluation of N3-Phenylpyrazinones as Novel Corticotropin-Releasing Factor-1 (CRF1) Receptor Antagonists

Evidence suggests that corticotropin-releasing factor-1 (CRF(1)) receptor antagonists may offer therapeutic potential for the treatment of diseases associated with elevated levels of CRF such as anxiety and depression. A pyrazinone-based chemotype of CRF(1) receptor antagonists was discovered. Structure-activity relationship studies led to the identification of numerous potent analogues including 12p, a highly potent and selective CRF(1) receptor antagonist with an IC(50) value of 0.26 nM. The pharmacokinetic properties of 12p were assessed in rats and Cynomolgus monkeys. Compound 12p was efficacious in the defensive withdrawal test (an animal model of anxiety) in rats. The synthesis, structure-activity relationships and in vivo properties of compounds within the pyrazinone chemotype are described.

Corticotrophin-releasing factor receptor antagonists

Corticotrophin-releasing factor (CRF) receptor antagonists have attracted considerable attention recently as potential therapeutics for a variety of neuropsychiatric disorders including anxiety, depression and anorexia nervosa. Preliminary results suggest the efficacy of CRF antagonists in animal models of anxiety/depression. This review will cover all patent activity up to and including August 1997 and will focus on the most relevant patents and publications relating to small molecule non-peptide CRF antagonists.

In Vitro Intrinsic Clearance-Based Optimization of N3-Phenylpyrazinones as Corticotropin-Releasing Factor-1 (CRF1) Receptor Antagonists

A series of pyrazinone-based heterocycles was identified as potent and orally active corticotropin-releasing factor-1 (CRF(1)) receptor antagonists. Selected compounds proved efficacious in an anxiety model in rats; however, pharmacokinetic properties were not optimal. In this article, we describe an in vitro intrinsic clearance-based approach to the optimization of pyrazinone-based CRF(1) receptor antagonists wherein sites of metabolism were identified by incubation with human liver microsomes. It was found that the rate of metabolism could be decreased by incorporation of appropriate substituents at the primary sites of metabolism. This led to the discovery of compound 12x, a highly potent (IC(50) = 1.0 nM) and selective CRF(1) receptor antagonist with good oral bioavailability (F = 52%) in rats and efficacy in the defensive withdrawal anxiety test in rats.

Purin-8-ones as corticotropin-releasing hormone (CRH-R1) receptor antagonists

A series of purin-8-ones was prepared and discovered to have excellent binding affinity to the CRH-R1 receptor. Structure-activity studies focused on amine side-chain optimization, urea substitution and pyridyl isostere incorporation. Thus, the highly potent purin-8-ones show promise as a new class of potential anxiolytics and/or antidepressants.

Stable isosteres of neurotensin c-terminal pentapeptides derived by modification of the amide function

Abstract A series of amide bond modified neurotensin c-terminal pentapeptides has been prepared and tested for their in vivo analgesic properties. Reduced amide function and trans double bond isosteres did show analgesic activity.

Alkylbenzyl ethers of hydroquinones as monoamine oxidase B inhibitors

A series of alkylbenzylethers of substituted hydroquinone analogs of 4-(3-chlorophenyl methyloxy)-phenoxybutyronitrile I, and alcohol II were synthesized as monoamine oxidase (MAO) inhibitors. Incorporation of electron-withdrawing groups on the hydroquinone afforded compounds with higher levels of activity and selectivity than I or II for MAO B inhibition.