Prediction of Total Phenolic Content in Extracts ofPrunellaSpecies from HPLC Profiles by Multivariate Calibration

Abstract

The multivariate calibration methods-principal component regression (PCR) and partial least squares (PLSs)-were employed for the prediction of total phenol contents of four Prunella species. High performance liquid chromatography (HPLC) and spectrophotometric approaches were used to determine the total phenol content of the Prunella samples. Several preprocessing techniques such as smoothing, normalization, and column centering were employed to extract the chemically relevant information from the data after alignment with correlation optimized warping (COW). The importance of the preprocessing was investigated by calculating the root mean square error (RMSE) for the calibration set of the total phenol content of Prunella samples. The models developed based on the preprocessed data were able to predict the total phenol content with a precision comparable to that of the reference of the Folin-Ciocalteu method. PLS model seems preferable, because of its predictive and describing abilities and good interpretability of the contribution of compounds to the total phenol content. Multivariate calibration methods were constructed to model the total phenol content of the Prunella samples from the HPLC profiles and indicate peaks responsible for the total phenol content successfully.

Phenolic Composition and Biological (Anti Diabetic and Antioxidant) Activities of Different Solvent Extracts of an Endemic Plant (Heliotropium Strigosum)

“…Methanol extract of H. strigosum exhibited significantly higher (P < 0.05) total phenolic contents (84.50 ± 0.06 µg GAE/ mg of plant extract). These results are in agreement with previous study, in which maximum amount of total phenolic contents was examined in methanol extract of medicinal plant 20,21 . Among the other solvent fractions, aqueous fraction (70.41 ± 0.82 µg GAE/ mg of plant extract) had the highest total phenolic contents followed by ethyl acetate (31.99 ± 1.57 µg GAE/ mg of plant extract), chloroform (25.36 ± 2.44 µg GAE/ mg of plant extract) and n-hexane (12.81 ± 0.93 µg GAE/ mg of plant extract) fractions.…”

Quantitative analysis of phenolic compounds in Syrian olive mill wastewater by spectrophotometry and HPLC

“…Chloroform is considered as a non-polar solvent while ethylacetate is considered as an aprotic solvent and methanol is considered as a protic solvent. The solvent most suitable for the extraction of phenols appeared to be ethylacetate in OMW [24] , and that what can explain the ability of chloroform to extract larger amount of phenol than methanol in this study. The presented results conform to those of another study, that ethylacetate exhibits a higher extraction power compared to other solvents such as methyl isobutyl ketone, methyl ethyl ketone, and diethyl ether, which was shown by Allouche [25] .…”

“…On the other hand, methanol and chloroform were present in lesser extent than ethylacetate (Table 2). Solvents with relatively lower polarity like ethylacetate were more efficient in general for extracting phenols [23,24] in OMW. On the other hand, pure solvents with higher polarity extracted significantly higher amounts of phenols than non-polar solvent.…”

Antioxidant, Antimicrobial Activities, and Characterization of Phenolic Compounds of Thyme (Thymus vulgaris L.), Sage (Salvia officinalis L.), and Thyme–Sage Mixture Extracts

“…Te antioxidant potential of the combined extracts is not only controlled by the concentration of phenolic compounds, but it is also dependent on the structure and the synergistic interactions between phenolic compounds against the oxidation process [11]. Te diferences between the antioxidant potential of thyme-sage extract and individual plant extracts could be explained by the number and position of substituted hydroxyl or methoxyl groups and glycosylation around the favonoid skeleton [30]. Since total phenolic and favonoid contents do not give a complete picture of the quality and quantity of the phenolic and favonoid constituents, GC-MS analyses can provide the most helpful information on individual phenolic [31,32].…”