Reports show that the best solvent for a plant A is not the same for a plant B. And sometime for the same plant there are variations from one author to another, from a vegetative part to another...
So for such studies I can just advise you to make a rapid screening to choose the most appropriate solvent for your sample.
Reports show that the best solvent for a plant A is not the same for a plant B. And sometime for the same plant there are variations from one author to another, from a vegetative part to another...
So for such studies I can just advise you to make a rapid screening to choose the most appropriate solvent for your sample.
I tend to agree with Pierre response. The following publications describe the effect of various solvents on phenolic extraction:
1-flavonoid content, and antioxidant activity of Limnophila aromatica
Quy Diem Do ,Artik Elisa Angkawijaya ,Phuong Lan Tran-Nguyen ,Lien Huong Huynh ,Felycia Edi Soetaredjo ,Suryadi Ismadji ,Yi-Hsu Ju
Abstract
Limnophila aromatica is commonly used as a spice and a medicinal herb in Southeast Asia. In this study, water and various concentrations (50%, 75%, and 100%) of methanol, ethanol, and acetone in water were used as solvent in the extraction of L. aromatica. The antioxidant activity, total phenolic content, and total flavonoid content of the freeze-dried L. aromatica extracts were investigated using various in vitro assays. The extract obtained by 100% ethanol showed the highest total antioxidant activity, reducing power and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity. The same extract also exhibited the highest phenolic content (40.5 mg gallic acid equivalent/g of defatted L. aromatica) and the highest flavonoid content (31.11 mg quercetin equivalent/g of defatted L. aromatica). The highest extraction yield was obtained by using 50% aqueous acetone. These results indicate that L. aromatica can be used in dietary applications with a potential to reduce oxidative stress.
2-Extraction of antioxidant components from peanut skins
By Valeria Nepote1 , Nelson R. Grosso*2 and C. A. Guzman1
The objective of this work was to extract antioxidant components from peanut skins using different solvents and to determine antioxidant activity of the extracts. Methanolic, ethanolic, acetonic and aqueous extracts were prepared from
defatted and non defatted peanut skins. Total dry matter content and total phenolic content, radical-scavenging activity and antioxidant activity in sunflower oil were determined from the extracts. The peanut skins used in this work had the following
proximate composition: 16.60% oil, 12.32% protein, 2.83% ash and 69.8% other components. High content of total dry matter was found in methanolic (17.11%), ethanolic (17.70%) and acetonic (18.54%) extracts from non defatted peanut skins. The acetonic extract from defatted peanut skins had lower dry matter extraction
than the non defatted peanut skin extract. High content of total phenolics was detected in methanolic (158.6 mg/g) and ethanolic (144.1 mg/g) extracts from deffated peanut skins. These last two extracts in concentration of 1 µg/mL, the radical-scavenging activities were 32.59% in methanolic extract and 31.5% in
ethanolic extract. All extracts (0.05% w/w) in sunflower oil showed antioxidant activity. This antioxidant activity from the extracts was lower than that activity from BHT.
3-ANTIOXIDANT AND ANTI-DENATURING ACTIVITES OF DEFATTED AND NON-DEFATTED METHANOLIC EXTRACTS OF THREE MEDICINAL PLANTS IN NIGERIA.
Anokwuru, C.P., Adaramola, F.B., Akirinbola, D., Fagbemi E., Onikoyi F.
Department of Basic Sciences, School of Science and Technology, Babcock University Ilisan Remo, Ogun State
Nigeria
ABSTRACT: The Phenolic content, antioxidant and anti-denaturing activities of deffated and non-deffated methanolic extract of Acalypha wilkesiana, Cnidoscolus aconitifolius and Vernonia amygdalina leaf were studied. The total phenolic content was determined using Folin-Ciocalteu’s method while antioxidant activities were carried out using 2,2-diphenyl-1-picryl hydrazine (DPPH) free radical scavenging and total reducing power. The In-vitro anti-inflammatory activity was carried out by inhibition of protein denaturation method. The result of the study showed that defatted extracts of all the three plants showed higher phenolic content compared to the non-defatted extracts. The non-defatted extracts of all the three plants showed higher DPPH scavenging activity while the defatted extracts exhibited higher reducing power. Furthermore, the defatted extracts of all the plants showed higher anti- denaturing activity compared to the non-defatted. In conclusion, defatting the three plants in this study increased phenolic contents of the extracts, enhanced their reducing power and anti-denaturing activity.