title: Liquid chromatography method for quantifying N-(4-hydroxyphenyl)retinamide and N-(4-methoxyphenyl)retinamide in tissues.
abstract: A simple and accurate high-performance liquid chromatography (HPLC) method was developed to measure levels of N-(4-hydroxyphenyl)retinamide (fenretinide, 4-HPR) and its main metabolite N-(4-methoxyphenyl)retinamide (4-MPR) in tissue. Following ultrasonic extraction of fresh tissue in acetonitrile (ACN), 4-HPR and 4-MPR were measured by HPLC with UV absorbance detection at 340 nm, using isocratic elution with ACN, H(2)O, and acetic acid. N-(4-ethoxyphenyl)retinamide (4-EPR) was employed as an internal standard. The 4-HPR and 4-MPR recovery in bovine liver or bovine brain tissue samples spiked with known amounts of 4-HPR and 4-MPR ranged from 93 to 110%. The detection limit of the method was 50 ng/ml. The method was tested on actual samples from an athymic (nu/nu) mouse carrying a subcutaneous tumor xenograft originating from SMS-KCNR neuroblastoma cells. The tissues were harvested and analyzed following a 3 day long treatment with intraperitoneal injections of 4-HPR/Diluent-12. 4-HPR and the metabolite 4-MPR were detected and quantitated in the tested tissues including tumor, liver, and brain. This method can be used to quantify 4-HPR and 4-MPR in different tissues to determine the bioavailability of 4-HPR.
authors.affiliation: Division of Hematology-Oncology, Childrens Hospital Los Angeles, Los Angeles, CA 90027, USA.
authors.forename: Jitka
authors.initials: J
authors.lastname: Vratilova
authors.forename: Tomas
authors.initials: T
authors.lastname: Frgala
authors.forename: Barry J
authors.initials: BJ
authors.lastname: Maurer
authors.forename: C
authors.initials: C
authors.lastname: Patrick Reynolds
mesh_terms: D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D017313:Fenretinide / Q000378:metabolism*; D051379:Mice; D008819:Mice, Nude; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet; D014212:Tretinoin / Q000031:analogs & derivatives* / Q000378:metabolism*
chemical_list: D017313:Fenretinide; D014212:Tretinoin; C058346:N-(4-methoxyphenyl)retinamide