title: Fluorine-tagged 5-hydroxytryptophan to investigate amino Acid metabolism in vivo.
abstract: Auxin a plant growth hormone, has a metabolic pathway that includes molecules and enzymes like those in animal brains. In this study, tomato plant seedlings (Lycopersicon esculenta) were used to investigate the fate of fluorine-tagged 5-hydroxytryptophan (PF-5-HTP) being developed for fluorine spectroscopy and imaging. Seedlings were treated with high or low concentrations of 5-HTP or PF-5-HTP and compared with controls. Metabolites of the PF-5-HTP were quantified using a custom immunoassay for the tag. Serotonin (5-HT) levels were measured with spectrofluorometry and thin-layer chromatography. Plants in treatment conditions had serotonin levels five to six times higher than controls. PF-5-HTP served as a precursor for serotonin in a biosynthetic pathway in this plant model, providing evidence for the bioavailability of the novel molecule. The increase in serotonin in plants grown in media culture supplemented with 5-HTP or PF-5-HTP might have useful applications in pharmacology.
authors.affiliation: Marist College, 3399 North Road, Poughkeepsie, NY 12601, USA.
authors.forename: Zofia E
authors.initials: ZE
authors.lastname: Gagnon
authors.forename: Sherry
authors.initials: S
authors.lastname: Dingman
authors.forename: Rhys N
authors.initials: RN
authors.lastname: Thomas