New Quinoxaline Derivatives as Potential MT1 and MT2 Receptor Ligands

Abstract

Ever since the idea arose that melatonin might promote sleep and resynchronize circadian rhythms, many research groups have centered their efforts on obtaining new melatonin receptor ligands whose pharmacophores include an aliphatic chain of variable length united to an N-alkylamide and a methoxy group (or a bioisostere), linked to a central ring. Substitution of the indole ring found in melatonin with a naphthalene or quinoline ring leads to compounds of similar affinity. The next step in this structural approximation is to introduce a quinoxaline ring (a bioisostere of the quinoline and naphthalene rings) as the central nucleus of future melatoninergic ligands.

Design, synthesis, and biological evaluation of novel arylcarboxamide derivatives as anti-tubercular agents

“… 41 Therefore, disrupting the two Asp–Tyr pairs blocks the proton motive force for substrate translocation. Towards this, bioisosteric replacements of the indole core by other aromatic moieties 42 have been employed. Hence, several quinolines 8a–k , 11a–g and 13a,b as well as naphthalene derivatives 13c–g were chosen ( Fig.…”

Synthesis and evaluation of antioxidant activity of new quinoline-2-carbaldehyde hydrazone derivatives: bioisosteric melatonin analogues

“…Uncorrected melting points were determined with a Büchi SMP-20 apparatus (Sigma, Steinheim, Germany). The 1 H and 13 C NMR spectra were recorded with a Varian 400 MHz using TMS as an internal standard and DMSO-d 6 as a solvent. ESI mass spectra were determined on a Waters micromass ZQ spectrometer (Waters, Milford, MA), FT-IR spectra were recorded on a Jasco 420Fourier instrument (Jasco, Portland, OR).…”

“…To determine the structural parameters of the antioxidant activity substitutions on the second position of the indole ring and of the alkyl chain of the acyl group have been underlined. Substitution of the indole ring of MLT with a naphthalene or quinolone ring leads to compounds of similar behavior 13 . Quinoline and their derivatives play important roles in the synthesis of natural products and as therapeutic agents, and constitute an important class of compounds for new drug development.…”

Synthesis and biological evaluation of quinoxaline di- N -oxide derivatives with in vitro trypanocidal activity

“…13 Our group has vast experience in the synthesis and biological evaluation of quinoxaline derivatives with anti-cancer, antimycobacterium and anti-inflammatory activities among others. [14][15][16][17][18][19][20][21][22][23][24][25][26] One of the projects has been focused on the study of novel quinoxaline derivatives as anti T. cruzi agents. In this field, over 200 derivatives have been prepared and evaluated as anti-trypanosomatid agents and some structural requirements have been established for their anti-chagasic in vitro activity.…”