Acetate → PyroGlu-D-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn

Participants

Reaction Steps

In 2 ml of trifluoroacetic acid is dissolved 240 mg of pGlu-(D)-Ala-Lys(Boc)-Ser-Gln-Gly-Gly-Ser-Asn-OBut and the solution is allowed to stand at room temperature for 60 minutes. The trifluoroacetic acid is distilled off and the residue is precipitated with ether and recovered by filtration. The powders thus obtained are dissolved in 30 ml of water and the solution is passed through a column of Amberlite IRA-410 (acetate-form)(2×4 cm). The effluent is combined with washings and lyophilized. The powdery lyophilizate is dissolved in a small amount of 0.1 N-aqueous acetic acid and put onto a column of Sephadex LH-20 (2.5×125 cm), elution being carried out with 0.1 N-aqueous acetic acid. The fractions from 195 ml through 240 ml are pooled and lyophilized, whereupon 150 mg powders of the indicated compound are obtained. Yield 68%; [α]D25 -16.6°(c=0.5, 50% acetic acid); Rf4 (Avicel)=0.20; amino acid analysis (as hydrolyzed with HCl): Lys, 1.18(1); Asp, 1.00(1); Ser, 1.67(2); Glu, 2.03(2); Gly, 2.09(2); Ala, 0.86(1); average recovery 79%.

Provenance & Evidence