This invention relates to a preparation of separating 4-hydroxyisoleucine from cucurbit seeds, belonging to research field of phytochemistry. By Lactonizating 4-hydroxyisoleucine that is in cucurbit seeds, (2S,3R,4S)- 4-hydroxyisoleucine internal ester is directly separated by utilizing column chromatography or method of solid liquid extraction, this internal ester is hydrolyzed in the condition of alkalinity to produce (2S, 3R,4S)-4-hydroxyisoleucine. Using this invention separates 4-hydroxyisoleucine from cucurbit seeds, not only obtains (2S,3R,4S)- 4-hydroxyisoleucine that is high purity with high yield, but also the line of separating depuration is convenient and feasible, it possesses production value of industrialization. |