Dicyclohexylcarbodiimide → HCID 131723815, compound

Participants

Reaction Steps

A photo-generatable derivative of biotin (so called caged biotin) was prepared by a modification of the method of Pirrung et al (Bioconj. Chem., 1996, 7, 317). This compound (9 mg) was dissolved in dichloromethane (5 ml) and treated with dicyclohexylcarbodimide (DCC) (3 mg), N-hydroxy succinimide (NHS) (2 mg) and dimethylaminopyridine (0.2 mg). After stirring at room temperature for two hours a derivative of gramicidin bearing two aminocaproyl groups linked end-to-end and attached to the terminal hydroxyl of gramicidin (prepared by conventional peptide chemistry techniques) was added (30 mg, as a solution in methanol (1 ml) and triethylamine (0.1 ml)). The solution was stirred for 18 hours, evaporated to dryness and then passed through a Sephadex LH-20 column eluting with dichloromethane-methanol-water (800:50:4). The main fraction was then purified by HPLC on a 40 mm×200 mm Waters Prep Nova-Pak® HR silica column (6 μm, 6 Å) eluting with dichloromethane-methanol-water (800:40:4) operating at a flow rate of 25 ml/min. The fraction, eluting at 24.5 minutes, possessed a 1H-nmr spectrum and mass spectrum in full agreement with the proposed structure.

Provenance & Evidence