title: Simultaneous extraction, optimization, and analysis of flavonoids and polyphenols from peach and pumpkin extracts using a TLC-densitometric method.
abstract: BACKGROUND
  The use of medicinal plants has been reported throughout human history. In the fight against illnesses, medicinal plants represent the primary health care system for 60 % of the world's population. Flavonoids are polyphenolic compounds with active anti-microbial properties; they are produced in plants as pigments. Quercetin, myricetin, and rutin are among the most well-known and prevalent flavonoids in plants, with an antioxidant activity capable of decreasing the oxidation of low density lipoproteins [LDLs]. To date, this research is the first of its kind to employ a coupled thin-layer chromatography (TLC) and a densitometric quantification method with a Box-Behnken design (BBD) response surface methodology (RSM) for optimization of ultrasonic-assisted extraction and determination of rutin and quercetin from peach and ellagic acid and myricetin from pumpkin fruits.
  
  
  RESULTS
  The effect of process variables (extraction temperature (°C), extraction power (%) and extraction time (min)) on ultrasound-assisted extraction (UAE) were examined by using BBD and RSM. TLC followed by Quantity-One™ (BioRad) image analysis as a simple and rapid method was used for identification and quantification of the compounds in complex mixtures. The results were consistent under optimal conditions among the experimental values and their predicted values. A mass spectrometry (MALDI-TOF MS) technique was also used to confirm the identity of the natural products in the TLC spots resolved.
  
  
  CONCLUSIONS
  The results show that the coupled TLC-densitometric methods & BBD can be a very powerful approach to qualitative and quantitative analysis of; rutin and quercetin from peach extracts; and ellagic acid and myricetin contents from pumpkin extracts.
authors.affiliation: Department of Plant, Soil and Agricultural Systems, Southern Illinois University, Carbondale, IL 62901 USA ; Department of Food Science, College of Agriculture, University of Basrah, Basrah, 61004 Iraq.
authors.forename: Ammar
authors.initials: A
authors.lastname: Altemimi
authors.affiliation: Department of Plant, Soil and Agricultural Systems, Southern Illinois University, Carbondale, IL 62901 USA.
authors.forename: Dennis G
authors.initials: DG
authors.lastname: Watson
authors.affiliation: SIUC Mass Spectrometry Facility, Department of Chemistry and Biochemistry, SIUC, Carbondale, IL 62901 USA.
authors.forename: Mary
authors.initials: M
authors.lastname: Kinsel
authors.affiliation: Department of Plant, Soil and Agricultural Systems, Southern Illinois University, Carbondale, IL 62901 USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Lightfoot
keywords: Densitometry; Ellagic acid; Mass spectrometry; Myricetin; Rutin; TLC; Ultrasound