Correlation between chromatographic fingerprint and antioxidant activity of Turnera diffusa (Damiana).
In the present contribution, the partial least squares (PLS) method was used to establish a correlation between the antioxidant activity (obtained by DPPH assay) and chromatographic profiles of TURNERA DIFFUSA extracts. Chromatograms were obtained using HPLC-DAD. A model was constructed using 40 samples with 2550 X variables corresponding to the responses obtained at different times; the Y variables consisted of experimental values of antioxidant activity of each extract (measured as EC₅₀). Prior to this analysis, alignment of chromatograms was performed based on consideration of seven high-intensity signals present in all samples. The PLS1 model was validated by cross-validations; its capacity was evaluated using correlation parameters R², root mean square error of calibration (RMSEC), and root mean square error of prediction (RMSEP). The best results were achieved with zero order chromatograms using five-point smoothing (R² = 0.96, RMSEC = 3.31, and RMSEP = 7.86). Under these conditions, the optimal number of components was five. The model was applied to the prediction of antioxidant activity of commercial products; no significant differences were found between the experimental and predicted antioxidant activities for 83 % of them.
Departamento de Química Analítica, Facultad de Medicina, U. A. N. L., Nuevo León, México.
Aurora
A
Garza-Juárez
Ma de la Luz
Mde L
Salazar-Cavazos
Ricardo
R
Salazar-Aranda
Jonathan
J
Pérez-Meseguer
Noemi Waksman
NW
de Torres
D000975:Antioxidants / Q000032:analysis* / Q000378:metabolism; D002138:Calibration / Q000592:standards; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D016018:Least-Squares Analysis; D008962:Models, Theoretical; D010936:Plant Extracts / Q000737:chemistry*; D011786:Quality Control; D015203:Reproducibility of Results; D013997:Time Factors; D029647:Turnera / Q000737:chemistry*
D000975:Antioxidants; D010936:Plant Extracts