A Comparison of Diosgenin, Phenolics, Fatty Acid Profiles and Mineral Contents with Free Radical Scavenging Activity of Trigonella L. Species From Section Cylindricae

In this study, the fatty acids composition, the total flavonoids, phenolics, and mineral contents of Trigonella species belonging to Cylindricae Section (T. spruneriana, T. sibthorpii, T. kotschyi, T. mesopotamica, T. cylindricae, T. cilicica, T. filipes, T. velutina, T. strangulata and T. smyrnea) were determined. Diosgenin content in seeds and aerial parts of these species was investigated by RP-HPLC. Furthermore, the phytochemical profiles and radical scavenging activities of the plants were evaluated. The oils contained high proportions of α-linolenic (29.7-42.1 %) and linoleic acids (26.6-40.3 %). All the seed extracts had higher concentrations of total flavonoids and phenolics than those of aerial parts. T. strangulata and T. spruneriana seeds showed the highest total phenolics (201.35±0.51 and 191.90±0.86 mg GAE/g, respectively) and flavonoids contents (121.84±0.05 and 128.04±0.09 mg RE/g, respectively). For the DPPH radical scavenging assay, the extracts of four species of Trigonella showed moderate radical scavenging activity. The seeds contained high concentrations of potassium, calcium and phosphorus while the aerial parts were rich in calcium and potassium. Phytochemical screening tests showed that saponins, flavonoids, coumarins and fixed oils were main secondary metabolites. The highest diosgenin level was detected in T. cilicica seed and aerial part extracts (0.52±0.013 and 0.16±0.005 mg/g, respectively).