title: Quantification of two isomeric flavones in rat colon tissue using reverse phase high performance liquid chromatography.
abstract: BACKGROUND
  Antineoplastic activity has been previously shown for two isomeric flavones, 5,7-dihydroxy-3,6,8-trimethoxy flavone (flavone A) and 3,5-dihydroxy-6,7,8-trimethoxy flavone (flavone B), against colon cancer cell lines (Thomas et al. in PLoS ONE 7:e39806, 5). Here, we present modified methods for the extraction and quantification of flavones A and B in rat colon tissue after intravenous dosing via high performance liquid chromatography, from the originally described procedure for extraction and quantification in rat plasma (Whitted et al. in J Chromatogr B Analyt Technol Biomed Life Sci 1001:150-155, 7).
  
  
  RESULTS
  Modifications included tissue homogenization (1 g tissue: 2 mL water), filtration of the supernatant with a PVDF membrane, and the use of only one calibration curve to determine the concentration of each flavone in colon tissue. Good separation was achieved and representative equations were linear with r2≥ 0.99 for both flavones. Precision and accuracy for flavone A ranged from 0.88-24.03 and 109-116%. Precision and accuracy for flavone B ranged from 1.62-33.56 and 98-113%. Concentrations of 1639 ± 601 ng/g flavone A and 5975 ± 2480 ng/g of flavone B were detected in rat colon tissue 6 h post dosing.
  
  
  CONCLUSIONS
  Modifications to the extraction methods for flavone A and flavone B from rat colon tissue had good separation, precision, and accuracy.
authors.affiliation: Department of Pharmaceutical Sciences, Gatton College of Pharmacy, East Tennessee State University, Box 70594, Johnson City, TN, 37614-1708, USA.
authors.forename: Crystal L
authors.initials: CL
authors.lastname: Whitted
authors.affiliation: Department of Pharmaceutical Sciences, Gatton College of Pharmacy, East Tennessee State University, Box 70594, Johnson City, TN, 37614-1708, USA.
authors.forename: Victoria E
authors.initials: VE
authors.lastname: Palau
authors.affiliation: Universidad de Ciencias Aplicadas y Ambientales, Bogotá, Colombia.
authors.forename: Ruben D
authors.initials: RD
authors.lastname: Torrenegra
authors.affiliation: Department of Environmental Engineering, Faculty of Engineering, Universidad El Bosque, Bogotá, Colombia.
authors.forename: Oscar E
authors.initials: OE
authors.lastname: Rodriguez
authors.affiliation: Department of Pharmaceutical Sciences, Gatton College of Pharmacy, East Tennessee State University, Box 70594, Johnson City, TN, 37614-1708, USA. harirfor@etsu.edu.
authors.forename: Sam
authors.identifier: http://orcid.org/0000-0002-2631-3756
authors.initials: S
authors.lastname: Harirforoosh
mesh_terms: D000818:Animals; D002138:Calibration; D045744:Cell Line, Tumor; D056148:Chromatography, Reverse-Phase; D003106:Colon / Q000737:chemistry*; D047309:Flavones / Q000737:chemistry*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results
chemical_list: D047309:Flavones
keywords: 3,5-Dihydroxy-6,7,8-trimethoxy flavone; 5,7-Dihydroxy-3,6,8-trimethoxy flavone; Cancer; Colon; Flavonoids; HPLC