反应详情

30 mg. of the tetrapeptide resin are hydrolyzed with 6 N hydrochloric acid in dioxane for 18 hours and the product assayed on the amino acid analyzer. It yields a ratio of Thr 1, Lys 1, Pro 1, Arg 1. The value for Arg is the sum of Arg, Orn and nitro Arg. The tetrapeptide is cleaved off the resin with hydrogen bromide in TFA at room temperature for 1- 1/2 hours. It is then dried in vacuo, washed twice with water and lyophilized. Its weight of 176 mg. represents a 78% yield based on Lys. It is then taken up in 10 ml. of methanol containing 10% acetic acid. This is then exposed to catalytic hydrogenation with twice its weight 350 mg. of palladium on barium sulfate in a hydrogen atmosphere at 60 pounds per square inch pressure with continuous shaking for 24 hours at which time no nitro Arg is detected at 271 mμ, the peak of absorption. An aliquot is again hydrolyzed with 6 N HC1 in water and assayed. This yields a comparable figure for Thr, Lys, Pro, and Arg.

1. customat room temperature
2. customfor 1- 1/2 hours
3. customIt is then dried in vacuo
4. washwashed twice with water
5. customthe peak of absorption