Abstract:

the extraction conditions of 4-hydroxyisoleucine from Trigonella foenungraecum planted in Tianshui of Gansu province were optimized by uniform design based on single factor tests of several factors such as  ratio of extractant to material, extraction time, temperature and extraction times. The results showed that the optimum ratio of water to material, extraction time, temperature and extraction times are 10:1 (ml/g), 2 h, 90 ℃ and twice, respectively. After concentration, the water extract of Trigonella foenungraecum was added with 90% ethanol, and then the mixture was centrifugalized to remove Trigonella foenungraecum gum. Subsequently, the supernatant was adsorbed with 732 strong acid styrene cation exchange resin. The desorption conditions of 4-hydroxyisoleucine were investigated. The results showed that the optimal addition amount of 90% ethanol is 5 times of volume of water extract of Trigonella foenungraecum. The optimal desorption conditions are as follows: ammonia water pH 9, its total amount for desoprtion 800 ml, and its flow rate for desorption 0.6 ml/min. Under the above conditions, the content of 4-hydroxyisoleucine in final product is about 40%. After used repeatedly 5 times, the resin needs regenerating.

Key words: Trigonella foenungraecum, 4-hydroxyisoleucine, extraction, purification