The prediction of the total antioxidant capacity (TAC) of ethyl acetate extracts of P.atlantica leaves from their entire chromatographic fingerprints, was determined by high performance liquid chromatography (HPLC). This approach does not require to quantification and identification of the peaks. Chromatograms were evaluated to determine whether specific peaks were responsible for the predicted TAC value and therefore could be used as markers. In the present study, 28 different extracts were obtained from male and female leaves of Pistacia atlantica , that were collected monthly from April to October during the year 2010 in two growing regions. TAC values of P.atlantica extracts were determined, using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and potassium ferricyanide (PFC) reduction methods. HPLC chromatographic fingerprints of the extracts of the P.atlantica leaves were pre-treated using several pre-processing techniques such as column centering, normalization followed by column centering, and Standard Normal Variate (SNV) transformation followed by column centering were employed to extract the chemically relevant information from the data after alignment with correlation optimized warping (COW). The multivariate calibration methods-Partial Least Squares (PLS) and Orthogonal Projections to Latent Structures (O-PLS) were employed for the prediction of total antioxidant activities of P.atlantica leaves. The regression coefficients of the resulting models were evaluated to indicate the peaks possibly responsible for the antioxidant activity. The O-PLS model seems preferable because of its predictive and describing abilities and good interpretability of the contribution of each compound to the total antioxidant activity. Several peaks in the chromatograms were recognized as very important for the construction of the model according to their large positive regression coefficients. The structural elucidation of the relevant peaks was achieved by negative ionisation LC–QTOF–MS. The phenolic compounds galloylquinic, gentisic acid, quinic acid and tetragalloylglucoside determined in P.atlantica extracts seem to be responsible for scavenging DPPH radical, while glucogallin, galloylshikimic acid, methyl gallate , digallic acid , trigalloylglucose and tetragalloylquinic were considered important for the prediction of TAC K3FeCN6.
|Title of host publication||XVIth Chimiometrie, Geneve, Switserland, 19-21 January 2015|
|Publication status||Published - 2015|
|Event||XVIth Chimiometrie, Geneve, Switserland, 19-21 January 2015 - , Switzerland|
Duration: 19 Jan 2015 → 21 Jan 2015
|Conference||XVIth Chimiometrie, Geneve, Switserland, 19-21 January 2015|
|Period||19/01/15 → 21/01/15|
- Chromatographic fingerprints, Antioxidant activity, Multivariate calibration, Pistacia atlantica leaves