Background: 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 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. Results: The 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. Conclusions: The 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.

Background: Organosulfur compounds usually present a reduced stability especially in the presence of oxygen. This research aimed to study the stability and antioxidant potential of the Allium ursinum watery extract. Results: The decrease of the antioxidant capacity verifies an exponential relation which may be formally associated to a kinetically pseudomonomolecular process. The exponential regression equation allows the half-life of the degradation process to be determined, this being 14 hours and 49 minutes in a watery environment at room temperature. Conclusions: The watery extract of Allium ursinum changes its proprieties in time. This might be explained by the network of hydrogen bonds in a watery environment which has a protective effect on the dissolved allicin molecule.

The purpose of the study is to develop a suitable analytical method in order to establish appropriate conditions for isolation and assay of the dominant compounds in extracts of Capsicum annuum. The studies are performed with standard substances to establish the HPLC conditions for complete separation of capsaicin and dihydrocapsaicin, the two major components of interest. Because of their prevalent apolar features, reverse phase chromatographic version was approached. Systematic studies on different eluents revealed the 65% methanol–35% water mixture as a proper mobile phase providing a complete separation of the components according to analytical claims. The results may be of interest to develop a specific analytical procedure with advanced specificity for quantitative assay of capsaicin and dihydrocapsaicin in pharmaceutical products and in foods.