Design of optimal solvent for extraction of bio–active ingredients from six varieties of Medicago sativa

Angela Caunii,Ioana Grozea,Ionel Samfira,Dorin Gaitin,George Pribac

doi:10.1186/1752-153x-6-123

Abstract

BackgroundExtensive research has been performed worldwide and important evidences were collected to show the immense potential of plants used in various traditional therapeutic systems. The aim of this work is to investigate the different extracting solvents in terms of the influence of their polarity on the extracting ability of bioactive molecules (phenolic compounds) from the M. sativa flowers.ResultsThe total phenolic content of samples was determined using the Folin Ciocalteu (FC) procedure and their antioxidant activity was assayed through in vitro radical decomposing activity using the radical DPPH° assay (IUPAC name for DPPH is (phenyl)–(2,4,6–trinitrophenyl) iminoazanium). The results showed that water was better than methanol and acetic acid for extracting bioactive compounds, in particular for total phenolic compounds from the flowers of alfalfa. The average content of bioactive molecules in methanol extract was 263.5±1.02 mg GAE/100g of dry weight lyophilized extract. The total phenolic content of the tested plant extracts was highly correlated with the radical decomposing activity. However, all extracts were free–radical inhibitors, but the water extract was more potent than the acetic and the methanol ones. The order of inhibitor effectiveness (expressed by IC50) proved to be: water extract (0.924mg/mL) > acetic acid extract (0.154mg/mL) > methanol (0.079mg/mL). The profiles of each extract (fingerprint) were characterized by FT–MIR spectroscopy.ConclusionsThe present study compares the fingerprint of different extracts of the M. sativa flowers, collected from the wild flora of Romania. The total phenolic content of the tested plant extracts was highly correlated with the radical decomposing activity. The dependence of the extract composition on the solvent polarity (acetic acid vs. methanol vs. water) was revealed by UV–VIS spectrometry and Infrared fingerprint.

Highlights

Extensive research has been performed worldwide and important evidences were collected to show the immense potential of plants used in various traditional therapeutic systems
The objective of the study was to screen the extracts resulting from M. sativa flowers for Total phenol content (TPC), using different extraction solvents
For an integrated image of the differences between plants, solvent type and concentrations of bioactive molecules extracted, the extraction factors (EF) mean values at 270–290 nm (EFAA1, EFW1, EFM1) and at 317–340 nm (EFAA2, EFW2, EFM2) were represented for each of the 6 samples

Summary

Introduction

Extensive research has been performed worldwide and important evidences were collected to show the immense potential of plants used in various traditional therapeutic systems. The common name of the herb Alfalfa (Medicago sativa) is Lucerne. In folk medicine, this herb is used in alternative herbal treatments. The medicinal value of the plants lies in their phytochemical components which produce definite physiological actions in the organism. The most important bioactive components are starch, carbohydrates, basic proteins (histones and L–lysine, L–arginine, aspartic and glutamic acids) and the non–protein amino acid (L–canaverine). M. sativa belongs to the Leguminosae family; it is called the "father of all plants" and is considered the green food of the millennium. The ingredients of the alfalfa plant are used fresh, in order to maintain the essential nutrients necessary for proper functioning of the whole body [2,3,4]

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