Design, synthesis, and biological evaluation of polyphenol derivatives as DYRK1A inhibitors. The discovery of a potentially promising treatment for Multiple Sclerosis.

Green tea and its natural components are known for their usefulness against a variety of diseases. In particular, the activity of main catechin Epigallocatechin gallate (EGCG) against Dual-specificity tyrosine-(Y)-phosphorylation Regulated Kinase-1A (DYRK1A) has been reported; here we are showing a structure-activity relationship (SAR) for EGCG against this molecular target. We have studied the influence of all four rings on the activity and the nature of its absolute geometry. This work has led to the identification of the more potent and stable trans fluoro-catechin derivative 1f (IC50 = 35 nM). This molecule together with a novel delivery method showed good efficacy in vivo when tested in a validated model of multiple sclerosis (EAE).

Development of Novel Fluorinated Polyphenols as Selective Inhibitors of DYRK1A/B Kinase for Treatment of Neuroinflammatory Diseases including Parkinson's Disease.

Natural polyphenol derivatives such as those found in green tea have been known for a long time for their useful therapeutic activity. Starting from EGCG, we have discovered a new fluorinated polyphenol derivative (1c) characterized by improved inhibitory activity against DYRK1A/B enzymes and by considerably improved bioavailability and selectivity. DYRK1A is an enzyme that has been implicated as an important drug target in various therapeutic areas, including neurological disorders (Down syndrome and Alzheimer's disease), oncology, and type 2 diabetes (pancreatic ß-cell expansion). Systematic structure-activity relationship (SAR) on trans-GCG led to the discovery that the introduction of a fluoro atom in the D ring and methylation of the hydroxy group from para to the fluoro atom provide a molecule (1c) with more desirable drug-like properties. Owing to its good ADMET properties, compound 1c showed excellent activity in two in vivo models, namely the lipopolysaccharide (LPS)-induced inflammation model and the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) animal model for Parkinson's disease.

Pharmacological and functional characterization of novel EP and DP receptor agonists: DP1 receptor mediates penile erection in multiple species.

INTRODUCTION: Despite the widespread use of prostaglandin E(1) as an efficacious treatment for male erectile dysfunction for more than two decades, research on prostanoid function in penile physiology has been limited. AIM: To characterize the pharmacological and physiological activity of novel subtype-selective EP and DP receptor agonists. METHODS: Radioligand binding and second messenger assays were used to define receptor subtype specificity of the EP and DP agonists. Functional activity was further characterized using isolated human and rabbit penile cavernosal tissue in organ baths. In vivo activity was assessed in rabbits and rats by measuring changes in cavernous pressure after intracavernosal injection of receptor agonists. MAIN OUTCOME MEASURES: Receptor binding and signal transduction, smooth muscle contractile activity, erectile function. RESULTS: In organ bath preparations of human cavernosal tissue contracted with phenylephrine, EP2- and EP4-selective agonists exhibited variable potency in causing relaxation. One of the compounds caused mild contraction, and none of the compounds was as effective as PGE(1) (EC(50) = 0.23 microM). There was no consistent correlation between the pharmacological profile (receptor binding and second messenger assays) of the EP agonists and their effect on cavernosal tissue tone. In contrast, the DP1-selective agonist AS702224 (EC(50) =29 nM) was more effective in relaxing human cavernosal tissue than either PGE(1), PGD(2) (EC(50) = 58 nM), or the DP agonist BW245C (EC(50) =59 nM). In rabbit cavernosal tissue, PGE(1) and PGD(2) caused only contraction, while AS702224 and BW245C caused relaxation. Intracavernosal administration of AS702224 and BW245C also caused penile tumescence in rabbits and rats. For each compound, the erectile response improved with increasing dose and was significantly higher than vehicle alone. CONCLUSIONS: These data suggest that AS702224 is a potent DP1-selective agonist that causes penile erection. The DP1 receptor mediates relaxation in human cavernosal tissue, and stimulates pro-erectile responses in rat and rabbit. Thus, rabbits and rats can be useful models for investigating the physiological function of DP1 receptors.

Synthesis and evaluation of a gamma-lactam as a highly selective EP2 and EP4 receptor agonist.

Gamma-lactam analogs (2) of EP(4) receptor agonists were identified by substitution of the pyrazolidinone ring (1) with a pyrrolidinone ring. Several compounds (such as 2a, 2h) with high potency, selectivity and acceptable PK profiles were discovered. These were assessed in animal models of ovulation induction and bronchoconstriction.

Synthesis and evaluation of novel pyrazolidinone analogs of PGE2 as EP2 and EP4 receptors agonists.

Replacement of the hydroxy cyclopentanone ring in PGE(2) with chemically more stable heterocyclic rings and substitution of the unsaturated alpha-alkenyl chain with a metabolically more stable phenethyl chain led to the development of potent and selective analogs of PGE(2). Compound 10f showed the highest potency and selectivity for EP(4) the receptor.

Novel diketopiperazine enhances motor and cognitive recovery after traumatic brain injury in rats and shows neuroprotection in vitro and in vivo.

The authors developed a novel diketopiperazine that shows neuroprotective activity in a variety of in vitro models, as well as in a clinically relevant experimental model of traumatic brain injury (TBI) in rats. Treatment with 1-ARA-35b (35b), a cyclized dipeptide derived from a modified thyrotropin-releasing hormone (TRH) analog, significantly reduced cell death associated with necrosis (maitotoxin), apoptosis (staurosporine), or mechanical injury in neuronal-glial cocultures. Rats subjected to lateral fluid percussion-induced TBI and then treated with 1 mg/kg intravenous 35b thirty minutes after trauma showed significantly improved motor recovery and spatial learning compared with vehicle-treated controls. Treatment also significantly reduced lesion volumes as shown by magnetic resonance imaging, and decreased the number of TUNEL-positive neurons observed in ipsilateral hippocampus. Unlike TRH or traditional TRH analogs, 35b treatment did not change mean arterial pressure, body temperature, or thyroid-stimulating hormone release, and did not have analeptic activity. Moreover, in contrast to TRH or typical TRH analogs, 35b administration after TBI did not alter free-magnesium concentration or cellular bioenergetic state. Receptor-binding studies showed that 35b did not act with high affinity at 50 classical receptors, channels, or transporters. Thus, 35b shows none of the typical physiologic actions associated with TRH, but possesses neuroprotective actions in vivo and in vitro, and appears to attenuate both necrotic and apoptotic cell death.

Dipolar Cycloaddition Route to Diverse Analogues of Cocaine: The 6- and 7-Substituted 3-Phenyltropanes.

In our quest for an antagonist or partial agonist of cocaine, access to certain 6- and 7-substituted 3-phenyltropanes of type I was required. Starting from 3-hydroxy-1-methyl-4-phenylpyridinium iodide, we disclose a pyridinium betaine-based dipolar cycloaddition route to tropenones of type II. In turn, we show how this intermediate can be transformed to type I products either through the copper-catalyzed conjugate addition reaction of Grignard reagents to the enones 7-9 or by the copper(I)-catalyzed cross coupling reaction of the allylic acetates 15a and 16a with Grignard reagents.

Discovery of novel prostaglandin analogs of PGE2 as potent and selective EP2 and EP4 receptor agonists.

Analogs of PGE(2) with introduction of diene groups at the omega-side chain have been synthesized and evaluated for their binding affinity for EP(2) and EP(4) receptors. An optimized analog (compound 9b) showed high potency and selectivity for the EP(4) receptor over other known receptors.

Mixed cocaine agonist/antagonist properties of (+)-methyl 4beta-(4-chlorophenyl)-1-methylpiperidine-3alpha-carboxylate, a piperidine-based analog of cocaine.

The present study investigated the pharmacological properties of a piperidine-based novel cocaine analog, namely, (+)-methyl 4beta-(4-chlorophenyl)-1-methylpiperidine-3alpha-carboxylic acid [(+)-CPCA]. Like cocaine, (+)-CPCA inhibited rat synaptosomal dopamine and norepinephrine uptake with high affinity, but was 33-fold less potent than cocaine in inhibiting serotonin uptake. Like cocaine, (+)-CPCA is a locomotor stimulant, although it was less potent and efficacious than cocaine. Importantly, pretreatment with (+)-CPCA dose dependently blocked the locomotor stimulant effects of cocaine in rats. (+)-CPCA completely substituted for cocaine in drug discrimination tests, although it was about 3 times less potent than cocaine. It was also self-administered by rats. Unexpectedly, (+)-CPCA did not enhance cocaine-induced convulsions in mice. As expected from rodent studies, rhesus monkeys readily self-administered (+)-CPCA. However, compared with cocaine, (+)-CPCA showed limited reinforcing properties in rats as assessed by both fixed and progressive ratio intravenous drug self-administration tests. These results collectively suggest that (+)-CPCA has an atypical pharmacological profile having both cocaine-like "agonist" and some cocaine "antagonist" properties. These properties of (+)-CPCA suggest that it may have utility in the treatment of cocaine craving and dependence.

Non-covalent thrombin inhibitors featuring P(3)-heterocycles with P(1)-monocyclic arginine surrogates.

Investigations on P(2)-P(3)-heterocyclic dipeptide surrogates directed towards identification of an orally bioavailable thrombin inhibitor led us to pursue novel classes of achiral, non-covalent P(1)-arginine derivatives. The design, synthesis, and biological activity of inhibitors NC1-NC30 that feature three classes of monocyclic P(1)-arginine surrogates will be disclosed: (1) (hetero)aromatic amidines, amines and hydroxyamidines, (2) 2-aminopyrazines, and (3) 2-aminopyrimidines and 2-aminotetrahydropyrimidines.

Non-covalent thrombin inhibitors featuring P3-heterocycles with P1-bicyclic arginine surrogates.

Novel, potent, and highly selective classes of thrombin inhibitors were identified, which resulted from judicious combination of P4-aromatics and P2-P3-heterocyclic dipeptide surrogates with weakly basic (calcd pKa approximately non-basic-8.6) bicyclic P1-arginine mimics. The design, synthesis, and biological activity of achiral, non-covalent, orally bioavailable inhibitors NC1-NC44 featuring P1-indazoles, benzimidazoles, indoles, benzotriazoles, and aminobenzisoxazoles is disclosed.