title: In vivo biodistribution of ginkgolide B, a constituent of Ginkgo biloba, visualized by MicroPET.
abstract: The in vivo dynamic behavior of ginkgolide B (GB), a terpene lactone constituent of the Ginkgo biloba extracts, in the living animal was visualized by positron emission tomographic (PET) imaging using a GB analogue labeled with the positron emitter (18)F. The in vivo imaging studies, combined with ex vivo dissection experiments, reveal that GB exists in 2 forms in the body: the original GB with its lactone rings closed and a second form with one of the rings open. The original GB in plasma is taken up rapidly by various organs including the liver, the intestine and possibly the stomach. Consequently, in plasma, the proportion of the ionized form of GB increases dramatically with time. Thereafter the ratio between the 2 forms appears to shift slowly towards equilibrium. The results suggest that more attention needs to be focused on in vivo dynamics between the 2 forms of GB.
authors.affiliation: Department of Chemistry, Columbia University, New York, NY, USA. mas2048@med.cornell.edu
authors.forename: Makiko
authors.initials: M
authors.lastname: Suehiro
authors.forename: Norman R
authors.initials: NR
authors.lastname: Simpson
authors.forename: Mark D
authors.initials: MD
authors.lastname: Underwood
authors.forename: John
authors.initials: J
authors.lastname: Castrillon
authors.forename: Koji
authors.initials: K
authors.lastname: Nakanishi
authors.forename: Ronald
authors.initials: R
authors.lastname: van Heertum
mesh_terms: D000818:Animals; D004224:Diterpenes / Q000493:pharmacokinetics*; D005462:Fluorine Radioisotopes / Q000493:pharmacokinetics; D020441:Ginkgo biloba; D046934:Ginkgolides; D007783:Lactones / Q000493:pharmacokinetics*; D008297:Male; D008517:Phytotherapy; D010936:Plant Extracts / Q000493:pharmacokinetics*; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D014018:Tissue Distribution; D014316:Tritium / Q000493:pharmacokinetics
chemical_list: D004224:Diterpenes; D005462:Fluorine Radioisotopes; D046934:Ginkgolides; D007783:Lactones; D010936:Plant Extracts; D019275:Radiopharmaceuticals; D014316:Tritium; C045856:ginkgolide B