Determination of the Total Polyphenols Content and Antioxidant Activity of Echinacea Purpurea Extracts Using Newly Manufactured Glassy Carbon Electrodes Modified with Carbon Nanotubes
| Autor: | Daniela Gitea, Pavel Otrisal, Flavia-Maria Pavel, Aurelia Cristina Nechifor, Florin Banica, Sebastian Nemeth, Tapan Behl, Delia Mirela Tit, Simona Bungau |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Antioxidant
medicine.medical_treatment antioxidant activity Bioengineering 02 engineering and technology Glassy carbon lcsh:Chemical technology 01 natural sciences Chitosan lcsh:Chemistry chemistry.chemical_compound carbon nanotubes (CNTs) medicine Chemical Engineering (miscellaneous) lcsh:TP1-1185 Voltammetry polyphenols Chemistry Process Chemistry and Technology 010401 analytical chemistry Tincture 021001 nanoscience & nanotechnology 0104 chemical sciences lcsh:QD1-999 Polyphenol Composition (visual arts) glassy carbon electrode (GCE) Cyclic voltammetry Echinacea purpurea extracts 0210 nano-technology Nuclear chemistry |
| Zdroj: | Processes, Vol 8, Iss 833, p 833 (2020) Processes Volume 8 Issue 7 |
| ISSN: | 2227-9717 |
| Popis: | A sensitive electrochemical method was used for the determination of the total phenolic content and antioxidant activity of Echinacea purpurea extracts. In this study, 3 glassy carbon electrodes (GCE) were used: one unmodified and the other two newly manufactured glassy carbon electrodes modified with carbon nanotubes (CNTs) and chitosan (CS) in different concentrations, having the following composition: 1 mg/mL CNTs/CS 5%/GCE and 20 mg/mL CNTs/CS 0.5%/GCE. The determinations were performed on 3 different pharmaceutical forms (capsules, tablets and tincture), which contain E. pururea extract from the root or aerial part of the plant. Standard chicoric and caftaric polyphenolic acids, as well as food supplements extracts, were characterized using voltammetry, in a Britton-Robinson (B-R) electrolyte buffer. The modified 1 mg/mL CNTs/CS 5%/GCE electrode has superior properties compared to the other two (the unmodified and 20 mg/mL CNTs/CS 0.5%/GCE-modified) electrodes used in the study. Echinacea tincture had the highest antioxidant capacity and the biggest total amount of polyphenols (28.72 mg/equivalent of 500 mg powder). Echinacea capsules had the lowest antioxidant capacity, but also the lowest total amount of polyphenols (19.50 mg/500 mg powder) similarly, tablets had approximately the same values of polyphenols content (19.80 mg/500 mg powder), and also antioxidant capacity. The total polyphenol content was consistent with the one indicated by the manufacturers. Pulse-differential cyclic voltammetry represents a rapid, simple and sensitive technique to establish the entire polyphenolic amount and the antioxidant activity of the E. purpurea extracts. |
| Databáze: | OpenAIRE |
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