Proceedings Volume 2010 (format .pdf) - SimpBTH

spectrophotometric method based on their property of forming stable yellowcompounds with Al 3+ , having maximum absorbtion at 450nm [6]Determination of total phenolics: Qualitative analyses for total phenolicswere carried out usig TLC methods [5]. Total phenolics content was determinedaccording to the Folin-Ciocalteu method using gallic acid, caffeic acid andchlorogenic acid as standards.[6]DPPH assay: In eitch reaction 50 µL vegetal extract of differentconcentrations was mixed with 2950µL of 0.0025g/L DPPH at room temperaturefor 30 min. 50% methanol solution was used as control. The reduction of the DPPHfree radical was measured by reading the absorbance at 517 nm. Rutin and caffeicacid were used as positive controls. Inhibition ratio (percent) was calculated fromthe following equation:% inhibition = absorbance of control – absorbance of sample x 100absorbance of control3. RESULTS AND DISCUSSIONSQualitative analyses for flavones and total phenols have been performedaccording to TLC Atlas - Plant Drug Analyses [20]:Adsorbent: Silica gel 60F254 – percolated TLC plates (Merck, Germany);Solvent system: Ethyl acetate-formic acid- acetic acid gl.– distilled water(100:11:11:26);Reference compounds: Sigma polyphenols prepared as standard solutions10 -3 M solved into methanol p.a. - 10 to 20µl of these standard solutions applied atthe starting line.Identification: pulverization with NP/PEG (natural products reagent)followed by exposure at 366nm.Obtained chromatograms for Lamium album revealed fluorescent (fl.) spotsattributed as following:-Rf~0.49- chlorogenic acid blue fl. spots;-Rf~0.94 – rosmarinic acid blue fl. spot;-Rf~0.96– caffeic acid blue fl. spots.Obtained chromatograms for Lamium purpureum revealed fluorescent (fl.)spots attributed as following:-Rf~0.4 – rutin orange fl. spot;-Rf~0.49 / chlorogenic acid blue fl. spots;-Rf~0.62- hyperoside orange fl.spot;-Rf~0.95 – rosmarinic acid blue fl. spot;-Rf~0.96– caffeic acid blue fl. spots.TLC studies reveals yhat chlorogenic acid, rosmarinic acid and caffeic acidare the main polyphenols compounds present in indigenous Lamium album20