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Medicago sativa L. (M. sativa) is a source of many valuable secondary metabolites. Extraction yield and the concentration of phenolics, flavonoids, and saponins, as well as antioxidant potential were determined in extracts from different parts of M. sativa obtained using extraction methods such as maceration, ultrasound-assisted extraction (UAE), accelerated solvent extraction (ASE), and supercritical fluid extraction (SFE). The concentrations of the listed groups of compounds were spectrophotometrically determined and confirmed by HPLC-MS. The results showed that ASE of flowers with 70% ethanol (EtOH) provided the highest yield of extraction (47.5 ± 4.0%), whereas the lowest yield was obtained in stems (4.0 ± 0.2%). The 70% EtOH extract from flowers showed the highest phenolic content [48.4 ± 4.6 mg gallic acid equivalents/g dry matter (DM)], as well as the highest antioxidant activity. The highest total flavonoid content (139.0 ± 7.1 mg rutin equivalents/g DM) was observed in the extract from leaves obtained through SFE. This extract was also especially rich in saponins [622.2 ± 30.3 mg oleanolic acid equivalents (OAE)/g DM]. However, the lowest compound content was observed in maceration extracts from stems (54.6 ± 27.0 mg OAE/g DM). The results suggest that EtOH extracts from alfalfa flowers and SFE extracts from M. satvia leaves, especially, may serve as potential sources of natural antioxidants for nutraceuticals, food additives, and cosmetic ingredients.

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Due to the important features of widely unexplored cyclitols, a comprehensive qualitative and quantitative study is needed. Moreover, measuring the possible available amounts of identified components in plant material represents a stringent need, due to their importance in phytomedicine and their use in food. The purpose of this study was to realize an extended investigation mainly of cyclitols, but of sugars and sugar alcohols as well, from natural sources. Thus, 17 target compounds (7 cyclitols and 2 sugar alcohols and 8 sugars) extracted from medicinal and edible plants are reported. All detected components were simultaneous separated in just one chromatographic run, using a single GC column. A number of 52 sources coming from 40 species were studied. Thus, we report 37 new sources of cyclitols. Moreover, almost for all cyclitols, the richest source was not investigated previously. Therefore, the obtained results can represent a valuable material for food, pharmaceutical, medical, or cosmetic industry interested in the use of cyclitols.

Saponins are widespread secondary metabolites with various beneficial properties: fungicidal, antibacterial, antiviral, and anticancer. Alfalfa saponin molecules contain mainly: medicagenic acid, hederagenin, bayogenin, and soyasapogenol B. Structural diversity of saponins makes their determination in Medicago sativa extracts very difficult. The most popular determination technique is high‐performance liquid chromatography applied with evaporative light scattering detection. Qualitative and quantitative analysis of sapogenins from Medicago sativa by high‐performance liquid chromatography with evaporative light scattering detection required hydrolysis and purification of extracts obtained by supercritical fluid extraction. Hydrolysis of saponins with concentrated hydrochloric acid provided high concentration of medicagenic acid. In the purification process, satisfactory results were obtained for solid‐phase extraction using octadecyl. Recoveries were from 71 to 99% with a standard deviation from 2 to 8. Hydrolysis with concentrated hydrochloric acid was the only method that allowed identification of all four analyzed sapogenins. Moreover, it is characterized by a short time of preparation, simplicity of execution, a small amount of the sample and solvents. The hydrolysis and purification methods coupled with high‐performance liquid chromatography and evaporative light scattering detection can be successfully used for qualitative and quantitative analysis of the main saponins present in Medicago sativa plant extracts obtained by supercritical fluid extraction.