In vitro study of antioxidant activity and phenolic content of Chrysanthemum balsamita varieties.

The purpose of our study was to identify the phenolic substances of two varieties of Chrysanthemum balsamita (balsamita and tanacetoides) and to measure the overall antioxidant activity. The phenolic compounds were determined by HPLC. The evaluation of the polyphenolic content was performed by colorimetric analysis. The antioxidant activity was measured by three in vitro assay models: the DPPH, the silver nanoparticles antioxidant capacity (SNPAC) and EPR radical detection. Using HPLC-MS analysis, phenolic acids, flavonoids and flavonoid aglycone were detected. The highest antioxidant activity was showed by Chrysanthemum balsamita var. balsamita, while the lowest for the Chrysanthemum balsamita var. tanacetoides extract, in accord with the polyphenolic content. The results show that Chrysanthemum balsamita var. balsamita might be a source of antioxidant flavonoids, especially rutin and isoquercitrin.

The study of polyphenolic compounds profile of some Rosmarinus officinalis L. extracts.

The purpose of this study was to compare the polyphenol profile of different Rosemary (Rosmarinus officinalis) extracts obtained from dry and fresh herb and the evaluation of their antioxidant effect. There were studied the polyphenols from hydroalcoholic extracts (1:5- dry plant:solvent) obtained from fresh respectively dry plant and the gemmotherapic extract obtained from fresh plant (1:20- dry plant: solvent). The polyphenol profile was evaluated by UV-Vis spectrophotometry, TLC and HPLC. The total polyphenol respectively flavonoids content were determined by UV-V is spectrophotometry. The antioxidant effect was evaluated by DPPH, ABTS, FRAP, CUPRAC and silver nanoparticle (SNP) methods. The hydroalcoholic extract obtained from fresh plant contains the highest concentration of total polyphenols, (0.601mg/ml rosmarinic acid), total flavonoids, (0.270mg/ml luteoline) and rosmarinic acid (0.350 mg/ml). The less concentrated is the gemmotherapic extract, but also the extraction ratio is higher than the hydroalcoholic extracts. The high content in polyphenols of the mentioned hydroalcoholic extract was confirmed by highest values of antioxidant activity: 39.1ml (DPPH), 7.7 ml (ABTS), 698mM ET/100 ml (FRAP), 1947 mM ET/100 ml (CUPRAC), 4570mM ET/100 ml (SNP). These differences in the polyphenols profiles show the importance of use the fresh plants for obtaining the good quality extracts.

Comparative studies on antioxidant activity and polyphenolic content of Lycium barbarum L. and Lycium chinense Mill. leaves.

The purpose of this research was to bring new data regarding the phenolic composition and the antioxidant activity of L. barbarum L. and L. chinense Mill. leaves. The determination of the main polyphenolic compounds was performed using a HPLC-UV-MS method. The dominant compound found for both species was rutin, with its highest amount registered in L. chinense (24141.90±21.3 µ/g plant material) leaves. Among the flavonoidic aglycones, quercetin was found in both samples, being quantified in a higher amount in L. chinense. In the antioxidant assays, both extracts exhibited important antioxidant activities, as witnessed by the three methods, both correlated with their total polyphenolic content.

Assessment of rosmarinic acid content in six Lamiaceae species extracts and their antioxidant and antimicrobial potential.

In the present study, six indigenous species of Lamiaceae family (Origanum vulgare L., Melissa officinalis L., Rosmarinus officinalis L., Ocimum basilicum L., Salvia officinalis L. and Hyssopus officinalis L.), have been analyzed to assess the rosmarinic acid, phenyl propane derivatives and polyphenolic contents and their antioxidant and antimicrobial potential. HPLC-MS method has been used for the analysis ofrosmarinicacid. The phenyl propane derivatives and total phenolic contents were determined using spectrophotometric method. The ethanolic extracts were screened for antioxidant activities by DPPH radical scavenging, HAPX (hemoglobin ascorbate per oxidase activity inhibition), and EPR (electron paramagnetic resonance) methods. The ethanolic extracts revealed the presence of rosmarinic acid in the largest amount in O. vulgare (12.40mg/g) and in the lowest in R. officinalis (1.33 mg/g). O. vulgare extracts exhibited the highest antioxidant capacity, in line with the rosmarinic acid and polyphenolic contents. The antimicrobial testing showed a significant activity against L. monocytogenes, S. aureus and C. albicans for all six extracts.

Comparative studies on polyphenolic composition, antioxidant and antimicrobial activities of Schisandra chinensis leaves and fruits.

The aim of this paper was to evaluate the antioxidant and antimicrobial activities and the polyphenolic content of Schisandra chinensis (Turcz.) Baill. leaves and fruits. The leaves are an important source of flavonoids (35.10 ± 1.23 mg RE/g plant material). Qualitative and quantitative analyses of the polyphenolic compounds were achieved using a HPLC-UV-MS method. The main flavonoid from the leaves was isoquercitrin (2486.18 ± 5.72 µg/g plant material), followed by quercitrin (1645.14 ± 2.12 µg/g plant material). Regarding the fruit composition, the dominant compound there was rutin (13.02 ± 0.21 µg/g plant material), but comparing with the leaves, fruits can be considered a poor source of phenolic compounds. The antioxidant activity was evaluated by DPPH, TEAC, hemoglobin ascorbate peroxidase activity inhibition (HAPX), inhibition of lipid peroxidation catalyzed by cytochrome c and EPR spectroscopic assays, revealing a better antioxidant activity for the S. chinensis leaves extract. In the antimicrobial assay, S. chinensis leaves extract showed efficient activities against the targeted bacteria, being more active than the fruits extract. The results suggest the leaves of S. chinensis as a valuable source of antioxidant compounds with significant antioxidant activity.