A series of forty-six aminooxy derivatives and thirty-six analogs of 7-aminobutyric acid was prepared and tested for inhibition of yaminobutyric acid transaminase and for protection against thiosemicarbazide-induced convulsions. Good in vivo activity in these tests was generally limited to certain a-aminooxyacids or their easily hydrolyzed derivatives, such as esters. None of the compounds studied was superior to aminooxyacetic acid.