The Taming of Capsaicin. Reversal of the Vanilloid Activity of N-Acylvanillamines by Aromatic Iodination
摘要:
Aromatic iodination ortho to the phenolic hydroxyl reverts the activity of the ultrapotent vanilloid agonist resiniferatoxin (RTX, 1a), generating the ultrapotent antagonist 5'-iodoRTX (1b). To better understand the role of iodine in this remarkable switch of activity, a systematic investigation on the halogenation of vanillamides, a class of compounds structurally simpler than resiniferonoids, was carried out. The results showed that (a) the antagonistic activity depends on the site of halogenation and is maximal at C-6', (b) iodine is more efficient than chlorine and bromine at reverting the agonistic activity, and (c) iodine-carbon exchange decreases antagonist activity. Iodine-induced reversal of vanilloid activity was also observed in vanillamides more powerful than capsaicin, but a poor correlation was found between agonistic and antagonistic potencies, suggesting that differences exist in the way vanillamides and their 6'-iodo derivatives bind to TRPV1".
The Taming of Capsaicin. Reversal of the Vanilloid Activity of <i>N</i>-Acylvanillamines by Aromatic Iodination
作者:Giovanni Appendino、Nives Daddario、Alberto Minassi、Aniello Schiano Moriello、Luciano De Petrocellis、Vincenzo Di Marzo
DOI:10.1021/jm050139q
日期:2005.7.1
Aromatic iodination ortho to the phenolic hydroxyl reverts the activity of the ultrapotent vanilloid agonist resiniferatoxin (RTX, 1a), generating the ultrapotent antagonist 5'-iodoRTX (1b). To better understand the role of iodine in this remarkable switch of activity, a systematic investigation on the halogenation of vanillamides, a class of compounds structurally simpler than resiniferonoids, was carried out. The results showed that (a) the antagonistic activity depends on the site of halogenation and is maximal at C-6', (b) iodine is more efficient than chlorine and bromine at reverting the agonistic activity, and (c) iodine-carbon exchange decreases antagonist activity. Iodine-induced reversal of vanilloid activity was also observed in vanillamides more powerful than capsaicin, but a poor correlation was found between agonistic and antagonistic potencies, suggesting that differences exist in the way vanillamides and their 6'-iodo derivatives bind to TRPV1".
Synthesis, photolysis studies and in vitro photorelease of caged TRPV1 agonists and antagonists
作者:Michael P. Van Ryssen、Nicolaos Avlonitis、Rashid Giniatullin、Craig McDougall、James L. Carr、Megan N. Stanton-Humphreys、Emma L. A. Borgström、C. Tom A. Brown、Dmitriy Fayuk、Alexander Surin、Minna Niittykoski、Leonard Khiroug、Stuart J. Conway
DOI:10.1039/b914981c
日期:——
The synthesis of a range of caged TRPV1 agonists and antagonists is reported. The photolysis characteristics of these compounds, when irradiated with a 355 nm laser, have been studied and in all cases the desired compound was produced. Photolysis of a caged TRPV1 agonist in cultured trigeminal neurons produced responses that were consistent with the activation of TRPV1 receptors.