Background: The seeds of Trigonella foenum-graecum L. (Fenugreek) are used in Iranian traditional medicine as blood sugar lowering agent. According to last investigations, hypoglycemic property is related to the amino acids of the plant specially 4-hydroxyisoleucine.

  Objective: In this research, identification and quantitative determination of 4-hydroxyisoleucine in Fenugreek seeds from Shahreza, central part of Iran, has been investigated.

  Methods: Powdered seeds of the plant were defatted and then extracted by using ethanol 50%. In order to isolation of 4-hydroxyisoleucine from the extract, ion exchange chromatography was used and the amino acid content was determined by using high performance liquid chromatography technique.

  Results: The results showed the presence of 0.4% 4-hydroxyisoleucine in the plant seeds which is considerable amount of the amino acid in the plant collected from Iran.