Discovery of novel and selective tertiary alcohol containing inhibitors of the norepinephrine transporter

One-pot enantioselective construction of 3,4-dihydro-2H-1,4-oxazines over Ru/Au relay catalysis and its mechanistic serendipity

One-pot enantioselective construction of 3,4-dihydro-2H-1,4-oxazines have been developed through the transfer hydrogenation/cyclization enantio-relay process using Ru and Au bimetallic catalysts.

Synthesis and fungicidal activity of 1,1-diaryl tertiary alcohols

A series of 1,1-diaryl tertiary alcohols and some of their dehydration derivatives were designed, synthesized and evaluated for their antifungal activities. Some compounds exhibited moderate inhibitory activities against seven plant pathogens at 50μg/mL in vitro, compounds 5g and 7c displayed nearly the same or higher fungicidal activities against some certain plant pathogens compared with the lead compound pyrimorph. A qualitative structure-activity relationship (SAR) analysis revealed that the Cl substituent and its position at the pyridine ring were crucial for the compounds' activities. Specially, several compounds displayed 100% protection effect against wheat powdery mildew or cucumber anthrax at 400mg/mL in vivo, which suggested that these compounds might be potential fungicidal candidates for certain plant diseases.

Discovery of a potent, dual serotonin and norepinephrine reuptake inhibitor

The objective of the described research effort was to identify a novel serotonin and norepinephrine reuptake inhibitor (SNRI) with improved norepinephrine transporter activity and acceptable metabolic stability and exhibiting minimal drug-drug interaction. We describe herein the discovery of a series of 3-substituted pyrrolidines, exemplified by compound 1. Compound 1 is a selective SNRI in vitro and in vivo, has favorable ADME properties, and retains inhibitory activity in the formalin model of pain behavior. Compound 1 thus represents a potential new probe to explore utility of SNRIs in central nervous system disorders, including chronic pain conditions.

1-(Indolin-1-yl)-1-phenyl-3-propan-2-olamines as potent and selective norepinephrine reuptake inhibitors

Efforts to identify new selective and potent norepinephrine reuptake inhibitors (NRIs) for multiple indications by structural modification of the previous 3-(arylamino)-3-phenylpropan-2-olamine scaffold led to the discovery of a novel series of 1-(indolin-1-yl)-1-phenyl-3-propan-2-olamines (9). Investigation of the structure-activity relationships revealed that small alkyl substitution at the C3 position of the indoline ring enhanced selectivity for the norepinephrine transporter (NET) over the serotonin transporter (SERT). Several compounds bearing a 3,3-dimethyl group on the indoline ring, 9k, 9o,p, and 9s,t, exhibited potent inhibition of NET (IC(50) = 2.7-6.5 nM) and excellent selectivity over both serotonin and dopamine transporters. The best example from this series, 9p, a potent and highly selective NRI, displayed oral efficacy in a telemetric rat model of ovariectomized-induced thermoregulatory dysfunction, a mouse p-phenylquinone (PPQ) model of acute visceral pain, and a rat spinal nerve ligation (SNL) model of neuropathic pain.

Synthesis of 11C-labelled (R)-OHDMI and CFMME and their evaluation as candidate radioligands for imaging central norepinephrine transporters with PET

(R)-1-(10,11-Dihydro-dibenzo[b,f]azepin-5-yl)-3-methylamino-propan-2-ol ((R)-OHDMI) and (S,S)-1-cyclopentyl-2-(5-fluoro-2-methoxy-phenyl)-1-morpholin-2-yl-ethanol (CFMME) were synthesized and found to be potent inhibitors of norepinephrine reuptake. Each was labelled efficiently in its methyl group with carbon-11 (t(1/2)=20.4 min) as a prospective radioligand for imaging brain norepinephrine transporters (NET) with positron emission tomography (PET). The uptake and distribution of radioactivity in brain following intravenous injection of each radioligand into cynomolgus monkey was examined in vivo with PET. After injection of (R)-[(11)C]OHDMI, the maximal whole brain uptake of radioactivity was very low (1.1% of injected dose; I.D.). For occipital cortex, thalamus, lower brainstem, mesencephalon and cerebellum, radioactivity ratios to striatum at 93 min after radioligand injection were 1.35, 1.35, 1.2, 1.2 and 1.0, respectively. After injection of [(11)C]CFMME, radioactivity readily entered brain (3.5% I.D.). Ratios of radioactivity to cerebellum at 93 min for thalamus, occipital cortex, region of locus coeruleus, mesencephalon and striatum were 1.35, 1.3, 1.3, 1.2 and 1.2, respectively. Radioactive metabolites in plasma were measured by radio-HPLC. (R)-[(11)C]OHDMI represented 75% of plasma radioactivity at 4 min after injection and 6% at 30 min. After injection of [(11)C]CFMME, 84% of the radioactivity in plasma represented parent at 4 min and 20% at 30 min. Since the two new hydroxylated radioligands provide only modest regional differentiation in brain uptake and form potentially troublesome lipophilic radioactive metabolites, they are concluded to be inferior to existing radioligands, such as (S,S)-[(11)C]MeNER, (S,S)-[(18)F]FMeNER-D(2) and (S,S)-[(18)F]FRB-D(4), for the study of brain NETs with PET in vivo.