The drug 'Donna' (6-diazo-5-oxo-norleucine) is an effective glutamine antagonist used in cancer treatment.

“but the one that works the best for us is Donna are there any that are in clinical trials in the United States yeah there's a couple is there's a name there's a few names of them you know they're they target various aspects of the glute ammonolysis pathway the problem is we have a drug that's called it's a dirty drug it hits multiple pathways of glutamine metabolism and it seems to work better than all the other drugs at least from our perspective so far which drug is done this is done the the six Norden or leucine”