New PET radiotracers may soon be coming down the pike, thanks to a chemical mechanism discovered by scientists at Berkeley Lab and UC Berkeley.

"Overall there are limited traditional organic chemistry mechanisms that are fast enough or scale well enough to allow efficient radiochemistry," James P. O'Neil, staff scientist and group leader at the Lawrence Berkeley National Laboratory, told HCB News.

When studying chemical reactions of a gold-containing molecule, the research team stumbled upon a chemical mechanism that can be used to form trifluoromethyl (CF3) compounds and attach them to other chemical compounds.
This discovery could aid in the development of new classes of PET radiotracers that have previously been too difficult or even impossible to prepare.

"While substantial interest has been given lately to the trifluoromethyl group in the context of radiotracer development for PET, attempts to access this group by nucleophilic and electrophilic radio fluorination protocols date back to 1979," said O'Neil.

The new chemical mechanism that's based on the discovery in gold chemistry, allows the team to attach a radioactive fluorine atom to a specific class of molecule that was previously challenging to do.

Drug companies have been increasingly interested in incorporating CF3 compounds in a range of pharmaceuticals because it makes them more selective, effective or potent. The antidepressant Prozac, HIV drug Sistiva and anti-inflammatory Celebrex are a few drugs that contain CF3 compounds.

O'Neil noted that the pharmaceutical field and diagnostic medicine field have been very limited in getting compounds that have been labeled with radioactive CF3, but yet there are a lot of drugs that have CF3 in them.

The team hopes to partner with a group that has a specific biological target or drug candidate of interest that contains a CF3 compound to adapt the new mechanism to the specific application. They can then work on developing radiotracers that incorporate the compound.

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