title: Novel high-performance liquid chromatographic assay using fluorescence detection for the quantitation of plasma gamma-methylene-10-deazaaminopterin and its major metabolite, 7-hydroxy-gamma-methylene-10-deazaaminopterin, in patients with solid cancers in a phase I trial.
abstract: Gamma-methylene-10-deazaaminopterin (MDAM), a unique dihydrofolate reductase inhibitor, has demonstrated antitumor activity against a broad spectrum of human solid tumors in preclinical studies. A novel reversed-phase, ion-pair high-performance liquid chromatography (HPLC) assay that uses fluorescence detection has been developed to quantitate levels of MDAM and its major metabolite, 7-hydroxy-gamma-methylene-10-deazaaminopterin (7-OH-MDAM), in human plasma. The recovery of MDAM and 7-OH-MDAM from plasma was >97% by a simple one-step deproteinization process using tetrabutylammonium bromide (TBABr) and methanol. MDAM and 7-OH-MDAM remained stable in plasma over a 28-day test period at ambient temperatures, and neither compound was light-sensitive. The limit of quantitation was 0.005 microM for both MDAM and 7-OH-MDAM. This assay has been found to be simple, sensitive and reproducible in determining plasma concentrations of MDAM and 7-OH-MDAM in patients with solid cancers in a phase I trial.
authors.affiliation: Division of Pharmacology and Experimental Therapeutics, The Johns Hopkins Oncology Center, Baltimore, MD 21287, USA.
authors.forename: H
authors.initials: H
authors.lastname: Su
authors.forename: T L
authors.initials: TL
authors.lastname: Chen
authors.forename: F H
authors.initials: FH
authors.lastname: Hausheer
authors.forename: E K
authors.initials: EK
authors.lastname: Rowinsky
mesh_terms: D000630:Aminopterin / Q000031:analogs & derivatives* / Q000097:blood / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000097:blood* / Q000627:therapeutic use; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D009369:Neoplasms / Q000097:blood* / Q000188:drug therapy; D011622:Pterins / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence
chemical_list: C108327:7-hydroxy-gamma-methylene-10-deazaaminopterin; D000970:Antineoplastic Agents; D011622:Pterins; C085593:gamma-methylene-10-deazaaminopterin; D000630:Aminopterin