Folin ciocateu phenol reagent

Already shed Carica papaya leaves (CPL) were collected from the commercial farm of Michael Okpara University of Agriculture Umudike, Abia state, Nigeria. The CPL were rinsed in running water to remove all the adhering dirt. The rinsed CPL were spread on a tray and air dried in Chemical Engineering laboratory for two weeks at room temperature of approximately 25 °C to attain a stable weight. After the sample drying, the CPL were pulverized, using an electric blender, screened with sieve aperture of 0.105 mm and kept in an airtight black polythene bag at 4 °C before the extraction experiment commenced. The moisture content of the air dried CPL sample was determined using the oven drying method and was found to be approximately 9% (w/w). The chemicals used in the course of experimentation such as sodium carbonate (Na₂CO₃) and Folin Ciocateu phenol reagent were purchased from Sigma Aldrich, Poole, England. Other HPLC grade phenolic standards were gallic acid, betulinic acid, chlorogenic acid, ellagic acid, ferulic acid, caffeic acid, quercetin and rutin and were procured from GFS Chemicals, Inc. USA (Sigma Aldrich, Germany). The distilled water was obtained from the Chemical Analysis Laboratory of Chemical Engineering Department, Michael Okpara University of Agriculture Umudike. All chemicals used were of analytical grades.

MEthanol (absolute) was bought from FlukaChemie GmbH (Sigma-Aldrich®, Zwijndrecht, Netherlands) and Dimethyl sulfoxide (DMSO) was purchased from RFCL Limited, Hayana, India. Dicholoro methane, ethyl acetate and Ethanol were purchased from LobaChemiePvt Ltd, Mumbai, India). 2,2-Diphenyl-1-picrylhydrazyl (DPPH) was bought from Sigma-Aldrich®.
Reagent for determination of active metabolites namely; Vanillin, Ascorbic acid, Gallic acid, Ammonium solution Concentrated sulphuric acid, Aluminium chloride, Catechin, Folin-Ciocateu’phenol reagent, Ferric chloride, Mayer’s reagent and Qualija were purchased from Sigma-Aldrich®.