Comparison of trigonelline content in some species of medicinal plant of fenugreek (Trigonella L.)

Fenugreek (Trigonella L.) is one of the most important and oldest known medicinal plants in the world, used in the treatment of many diseases due to its various secondary metabolites. The plant has more than 135 species growing throughout the world and in most climates. Trigonelline is the most important and most abundant alkaloid and one of the valuable metabolites found in fenugreek that is used to treat diabetes and reduce blood lipids. In this research, 22 genotypes from 10 species of fenugreek including: T. uncata, T. monantha, T. persica, T. anguina, T. stellate, T. spruneriana, T. astroites, T. monspeliaca, T. tehranica and T. foenum-graecum were collected from Khuzestan, Tehran, and Hormozgan provinces and their trigonelline levels were measured using HPLC technique. The results showed that T. foenum-graecum and T. tehranica had higher trigonelline content (1.34 and 0.9 mg/g seed, respectively) than other species. Also, there was a significant difference between genotypes for trigonelline content. The clustering based on Ward’s method separated genotypes into two groups. This study could be the basis for further work on the extraction of pharmaceutical compounds from other fenugreek species, especially native species of Iran such as T. tehranica.