Isatin: identity with the purified endogenous monoamine oxidase inhibitor tribulin.
Purified tribulin, an endogenous monoamine oxidase (MAO) inhibitor, has been identified by direct probe insertion mass spectrometry as the indole-2,3-dione, isatin. A gas chromatographic-mass spectrometric assay for isatin has been developed and used to measure its relatively high concentrations in unpurified human urine, and in rat heart and brain. Isatin is a known compound with a broad range of biological activity; this is the first report of its presence in the animal body. Isatin is a potent inhibitor of MAO, particularly of MAO B (IC50, 3 microM), and also binds to central benzodiazepine receptors (IC50 against clonazepam, 123 microM).
Glover
V
V
Department of Chemical Pathology, Queen Charlotte's Hospital, London, England.
Halket
J M
JM
Watkins
P J
PJ
Clow
A
A
Goodwin
B L
BL
Sandler
M
M
D000818:Animals; D001923:Brain Chemistry; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007211:Indoles / Q000032:analysis*; D007510:Isatin / Q000032:analysis*; D008996:Monoamine Oxidase Inhibitors / Q000032:analysis*; D009206:Myocardium / Q000032:analysis; D051381:Rats
D007211:Indoles; D008996:Monoamine Oxidase Inhibitors; D007510:Isatin; C039776:tribulin