Ninhydrin → Sodium 4-sulfophenylthiourea

Participants

Reaction Conditions

Reaction Steps

Solid sodium 4-sulfophenylisothiocyanate monohydrate (2.55 g; 10 mmol) was added to a solution of poly-L-lysine (15-30K) (Sigma Chemical Company) (1.0 g) in a mixture of water (20 ml) and N,N-dimethyl-N-allylamine buffer (pH 9.5; 15 ml). The resulting mixture was heated under nitrogen at 53° C. for 3 hours, when a ninhydrin test was negative. The cooled mixture was filtered and the filtrate concentrated to give a grey solid residue. The solid residue was redissolved in water and passed through a column of Amberlite IR 120(Na) and then concentrated. The crude product was purified by gel filtration (Sephadex LH20; water) and freeze dried to give sodium 4-sulfophenylthiourea terminated poly-L-lysine BRI2995 as a white fluffy solid (1.25 g).

Provenance & Evidence