Competitive antagonism of insect GABA receptors by iminopyridazine derivatives of GABA
摘要:
A series of 4-(6-imino-3-aryl/heteroarylpyridazin-1-yl) butanoic acids were synthesized and examined for antagonism of GABA receptors from three insect species. When tested against small brown planthopper GABA receptors, the 3,4-methylenedioxyphenyl and the 2-naphthyl analogues showed complete inhibition of GABA-induced fluorescence changes at 100 mu M in assays using a membrane potential probe. Against common cutworm GABA receptors, these analogues displayed approximately 86% and complete inhibition of GABA-induced fluorescence changes at 100 mu M, respectively. The 4-biphenyl and 4-phenoxyphenyl analogues showed moderate inhibition at 10 mu M in these receptors, although the inhibition at 100 mu M was not complete. Against American cockroach GABA receptors, the 4-biphenyl analogue exhibited the greatest inhibition (approximately 92%) of GABA-induced currents, when tested at 500 mu M using a patch-clamp technique. The second most active analogue was the 2-naphthyl analogue with approximately 85% inhibition. The 3-thienyl analogue demonstrated competitive inhibition of cockroach GABA receptors. Homology modeling and ligand docking studies predicted that hydrophobic 3-substituents could interact with an accessory binding site at the orthosteric binding site. (C) 2012 Elsevier Ltd. All rights reserved.
Competitive antagonism of insect GABA receptors by iminopyridazine derivatives of GABA
摘要:
A series of 4-(6-imino-3-aryl/heteroarylpyridazin-1-yl) butanoic acids were synthesized and examined for antagonism of GABA receptors from three insect species. When tested against small brown planthopper GABA receptors, the 3,4-methylenedioxyphenyl and the 2-naphthyl analogues showed complete inhibition of GABA-induced fluorescence changes at 100 mu M in assays using a membrane potential probe. Against common cutworm GABA receptors, these analogues displayed approximately 86% and complete inhibition of GABA-induced fluorescence changes at 100 mu M, respectively. The 4-biphenyl and 4-phenoxyphenyl analogues showed moderate inhibition at 10 mu M in these receptors, although the inhibition at 100 mu M was not complete. Against American cockroach GABA receptors, the 4-biphenyl analogue exhibited the greatest inhibition (approximately 92%) of GABA-induced currents, when tested at 500 mu M using a patch-clamp technique. The second most active analogue was the 2-naphthyl analogue with approximately 85% inhibition. The 3-thienyl analogue demonstrated competitive inhibition of cockroach GABA receptors. Homology modeling and ligand docking studies predicted that hydrophobic 3-substituents could interact with an accessory binding site at the orthosteric binding site. (C) 2012 Elsevier Ltd. All rights reserved.
A series of 4-(6-imino-3-aryl/heteroarylpyridazin-1-yl) butanoic acids were synthesized and examined for antagonism of GABA receptors from three insect species. When tested against small brown planthopper GABA receptors, the 3,4-methylenedioxyphenyl and the 2-naphthyl analogues showed complete inhibition of GABA-induced fluorescence changes at 100 mu M in assays using a membrane potential probe. Against common cutworm GABA receptors, these analogues displayed approximately 86% and complete inhibition of GABA-induced fluorescence changes at 100 mu M, respectively. The 4-biphenyl and 4-phenoxyphenyl analogues showed moderate inhibition at 10 mu M in these receptors, although the inhibition at 100 mu M was not complete. Against American cockroach GABA receptors, the 4-biphenyl analogue exhibited the greatest inhibition (approximately 92%) of GABA-induced currents, when tested at 500 mu M using a patch-clamp technique. The second most active analogue was the 2-naphthyl analogue with approximately 85% inhibition. The 3-thienyl analogue demonstrated competitive inhibition of cockroach GABA receptors. Homology modeling and ligand docking studies predicted that hydrophobic 3-substituents could interact with an accessory binding site at the orthosteric binding site. (C) 2012 Elsevier Ltd. All rights reserved.