Design, synthesis and biological evaluation of novel tetrahydroisoquinoline quaternary derivatives as peripheral κ-opioid receptor agonists

Carbonylation of Polyfluorinated 1-Arylalkan-1-ols and Diols in Superacids

We describe the carbonylation of a series of mono and dihydroxy derivatives of polyfluorinated alkylbenzenes and benzocycloalkenes with OH groups at benzylic positions using carbon monoxide in the presence of a superacid (TfOH, a TfOH-SbF₅ mixture, or a FSO₃H-SbF₅ mixture). It was shown that the superacid-catalyzed addition of CO to various primary and secondary polyfluorinated alcohols and diols gives the corresponding mono- and dicarboxylic acids or lactones. The efficiency of various superacids depending on alcohol structure was evaluated, and FSO₃H-SbF₅ yielded the best results in most transformations. The addition of CO to secondary 1-arylalkan-1-ols containing vicinal fluorine atoms was found to be accompanied by elimination of HF with the formation of α,β-unsaturated aryl-carboxylic acids. In contrast to primary and secondary alcohols, conversion of tertiary perfluoro-1,1-diarylalkan-1-ols into carbonylation products is not complete, and the resulting carboxylic acids are easily decarboxylated after water treatment of the reaction mixture.

Efficient synthesis and characterization of novel indolizines: exploration of in vitro COX-2 inhibitory activity and molecular modelling studies

Novel indolizine scaffolds as COX-2 inhibiting agents.

Design and Synthesis of Enantiomerically Pure Decahydroquinoxalines as Potent and Selective κ-Opioid Receptor Agonists with Anti-Inflammatory Activity in Vivo

In order to develop novel κ agonists restricted to the periphery, a diastereo- and enantioselective synthesis of (4aR,5S,8aS)-configured decahydroquinoxalines 5-8 was developed. Physicochemical and pharmacological properties were fine-tuned by structural modifications in the arylacetamide and amine part of the pharmacophore as well as in the amine part outside the pharmacophore. The decahydroquinoxalines 5-8 show single-digit nanomolar to subnanomolar κ-opioid receptor affinity, full κ agonistic activity in the [³⁵S]GTPγS assay, and high selectivity over μ, δ, σ₁, and σ₂ receptors as well as the PCP binding site of the NMDA receptor. Several analogues were selective for the periphery. The anti-inflammatory activity of 5-8 after topical application was investigated in two mouse models of dermatitis. The methanesulfonamide 8a containing the (S)-configured hydroxypyrrolidine ring was identified as a potent (K_i = 0.63 nM) and highly selective κ agonist (EC₅₀ = 1.8 nM) selective for the periphery with dose-dependent anti-inflammatory activity in acute and chronic skin inflammation.

Tetrahydroisoquinolines in therapeutics: a patent review (2010-2015)

INTRODUCTION

1,2,3,4-Tetrahydroisoquinoline (THIQ) is one of the 'privileged scaffolds', commonly found in nature. Initially, this class of compounds was known for its neurotoxicity. Later on, 1-methyl-1,2,3,4-tetrahydroisoquinoline was proved as an endogeneous Parkinsonism-preventing agent in mammals. The fused THIQs have been studied for their role as anticancer antibiotics. The US FDA approval of the trabectedin for the treatment of soft tissue sarcomas, is a milestone in the anticancer drug discovery. Areas covered: This review covers the patents on various therapeutic activities of the THIQ derivatives in the years between 2010 and 2015. Patents were collected using a thorough search of Espacenet and WIPO databases. The therapeutic areas covered include cancer, malaria, central nervous system (CNS), cardiovascular, metabolic disorders, and so on. This also includes several patents on specific THIQs of clinical importance. Expert opinion: A large number of the THIQ derivatives have been synthesised for various therapeutic activities, with noticeable success in the area of drug discovery for cancer and CNS. They may also prove to be promising candidates for various infectious diseases, such as malaria, tuberculosis, HIV-infection, HSV-infection, leishmaniasis, etc. They can also be developed as novel class of drugs for various therapeutic activities with unique mechanism of action.

Antinociceptive Effect of 3-(2,3-Dimethoxyphenyl)-1-(5-methylfuran-2-yl)prop-2-en-1-one in Mice Models of Induced Nociception

The antinociceptive effects produced by intraperitoneal administration of a novel synthetic chalcone, 3-(2,3-dimethoxyphenyl)-1-(5-methylfuran-2-yl)prop-2-en-1-one (DMFP), were investigated in several mouse models of induced nociception. The administration of DMFP (0.1, 0.5, 1.0 and 5.0 mg/kg) produced significant attenuation on the acetic acid-induced abdominal-writhing test. It also produced a significant increase in response latency time in the hot-plate test and a marked reduction in time spent licking the injected paw in both phases of the formalin-induced paw-licking test. In addition, it was also demonstrated that DMFP exhibited significant inhibition of the neurogenic nociceptive response induced by intraplantar injections of capsaicin and glutamate. Moreover, the antinociceptive effect of DMFP in the acetic acid-induced abdominal-writhing test and the hot-plate test was not antagonized by pretreatment with a non-selective opioid receptor antagonist, naloxone. Finally, DMFP did not show any toxic effects and/or mortality in a study of acute toxicity and did not interfere with motor coordination during the Rota-rod test. Our present results show that DMFP exhibits both peripheral and central antinociceptive effects. It was suggested that its peripheral antinociceptive activity is associated with attenuated production and/or release of NO and various pro-inflammatory mediators, while central antinociceptive activity seems to be unrelated to the opioidergic system, but could involve, at least in part, an interaction with the inhibition of capsaicin-sensitive fibers and the glutamatergic system.