The First Novel Fluorescent Cannabinoid Ligand, Tocrifluour T1117, Available Exclusively from Tocris Bioscience

Tocris Bioscience is pleased to announce the launch of Tocrifluor T1117. Co developed by Tocris and the University of Glasgow, Tocrifluor T1117 is the CB1 antagonist AM 251 labelled with a rhodamine derivative, and is the first fluorescent cannabinoid ligand commercially available.

New research published by Daly et al (2008) (1) has now shown that Tocrifluor T1117 is a novel and potentially very powerful tool for identifying the cellular location of cannabinoid receptors, including GPR551.

Dr. Craig Daly, Research Fellow at the University of Glasgow, said, "The role of cannabinoids in the cardiovascular system is both complicated and fascinating. We have found that T1117 has fluorescent properties ideally suited for analysing its binding in unfixed, thick biological specimens (i.e. blood vessels). T1117 is very stable under confocal laser excitation, has a good fluorescent yield, does not appear to be toxic and binds to similar (but not identical) sites as those recognised by other vasoactive fluorescent ligands for adrenergic receptors. T1117 should be a very useful tool for fluorescence based receptor studies."

The CB1 receptor, also known as the central cannabinoid receptor, is a member of the cannabinoid receptor group of G-protein-coupled receptors that also includes CB2. CB1 receptors are found mainly in the terminals of central and peripheral neurons where they usually mediate inhibition of neurotransmitter release. They can also be present on some non-neuronal cells, including immune cells.

GPR55 was identified and cloned for the first time in 1999. Later it was identified as a putative cannabinoid receptor because of a similar amino acid sequence in the binding region. Consistent with this, GPR55 is activated by endogenous, plant and synthetic cannabinoids and this profile as a distinct non-CB1/CB2 receptor has led to suggestions that GPR55 be categorised as the CB3 receptor.

Duncan Crawford, Tocris’ Chief Scientific Officer, said, “Novel products have always been an essential component of Tocris’ range. We anticipate that the ability of Tocrifluor T1117 to pinpoint these receptors will be of great benefit to life scientists.”


1. Daly et al (2008) Vascular and Smooth Muscle Phys.Soc. Symposium 2008.