206559-42-4Relevant articles and documents
Receptor activity and conformational analysis of 5′-halogenated resiniferatoxin analogs as TRPV1 ligands
Lim, Kwang Su,Kang, Dong Wook,Kim, Yong Soo,Kim, Myeong Seop,Park, Seul-Gi,Choi, Sun,Pearce, Larry V.,Blumberg, Peter M.,Lee, Jeewoo
, p. 299 - 302 (2011/02/27)
A series of 5′-halogenated resiniferatoxin analogs have been investigated in order to examine the effect of halogenation in the A-region on their binding and the functional pattern of agonism/antagonism for rat TRPV1 heterologously expressed in Chinese hamster ovary cells. Halogenation at the 5-position in the A-region of RTX and of 4-amino RTX shifted the agonism of parent compounds toward antagonism. The extent of antagonism was greater as the size of the halogen increased (I > Br > Cl > F) while the binding affinities were similar, as previously observed for our potent agonists. In this series, 5-bromo-4-amino RTX (39) showed very potent antagonism with K i (ant) = 2.81 nM, which was thus 4.5-fold more potent than 5′-iodo RTX, previously reported as a potent TRPV1 antagonist. Molecular modeling analyses with selected agonists and the corresponding halogenated antagonists revealed a striking conformational difference. The 3-methoxy of the A-region in the agonists remained free to interact with the receptor whereas in the case of the antagonists, the compounds assumed a bent conformation, permitting the 3-methoxy to instead form an internal hydrogen bond with the C4-hydroxyl of the diterpene.
Halogenation of 4-hydroxy/amino-3-methoxyphenyl acetamide TRPV1 agonists showed enhanced antagonism to capsaicin
Kang, Dong Wook,Kim, Yong Soo,Lim, Kwang Su,Kim, Myeong Seop,Pearce, Larry V.,Pavlyukovets, Vladimir A.,Tao, Andy K.,Lang-Kuhs, Krystle A.,Blumberg, Peter M.,Lee, Jeewoo
experimental part, p. 8092 - 8105 (2011/01/13)
As an extension of our analysis of the effect of halogenation on thiourea TRPV1 agonists, we have now modified selected 4-hydroxy(or 4-amino)-3- methoxyphenyl acetamide TRPV1 agonists by 5- or 6-halogenation on the aromatic A-region and evaluated them for potency for TRPV1 binding and regulation and for their pattern of agonism/antagonism (efficacy). Halogenation shifted the functional activity at TRPV1 toward antagonism with a greater extent of antagonism as the size of the halogen increased (I > Br > Cl), as previously observed for the thiourea series. The extent of antagonism was greater for halogenation at the 5-position than at the 6-position, in contrast to SAR for the thiourea series. In this series, compounds 55 and 75 showed the most potent antagonism, with Ki (ant) = 2.77 and 2.19 nM, respectively, on rTRPV1 expressed in Chinese hamster ovary cells. The compounds were thus ca. 40-60-fold more potent than 6′-iodononivamide.