title: Evaluation of Biologically Active Compounds from Calendula officinalis Flowers using Spectrophotometry.
abstract: BACKGROUND
  This study aimed to quantify the active biological compounds in C. officinalis flowers. Based on the active principles and biological properties of marigolds flowers reported in the literature, we sought to obtain and characterize the molecular composition of extracts prepared using different solvents. The antioxidant capacities of extracts were assessed by using spectrophotometry to measure both absorbance of the colorimetric free radical scavenger 2,2-diphenyl-1-picrylhydrazyl (DPPH) as well as the total antioxidant potential, using the ferric reducing power (FRAP) assay.
  
  
  RESULTS
  Spectrophotometric assays in the ultraviolet-visible (UV-VIS) region enabled identification and characterization of the full range of phenolic and flavonoids acids, and high-performance liquid chromatography (HPLC) was used to identify and quantify phenolic compounds (depending on the method of extraction). Methanol ensured more efficient extraction of flavonoids than the other solvents tested.Antioxidant activity in methanolic extracts was correlated with the polyphenol content.
  
  
  CONCLUSIONS
  The UV-VIS spectra of assimilator pigments (e.g. chlorophylls), polyphenols and flavonoids extracted from the C. officinalis flowers consisted in quantitative evaluation of compounds which absorb to wavelengths broader than 360 nm.
authors.affiliation: Chemistry and Biochemistry Department,Banat's University of Agricultural Sciences and Veterinary Medicine from Timisoara, Calea Aradului, no, 119, Timisoara, 300645 Romania. monicabutnariu@yahoo.com.
authors.forename: Monica
authors.initials: M
authors.lastname: Butnariu
authors.forename: Cristina Zepa
authors.initials: CZ
authors.lastname: Coradini