Patent ID: 7619121

Claim:
A method of isolating a thiol R′SH from a thiol-containing mixture, the method including the steps of forming a mixed disulphide R′SSR of the thiol R′SH by reacting the thiol R′SH with a second mixed disulphide R″SSR, in which R is a hydrophobic moiety which is not immobilised on a stationary phase, and R″ is selected so that a forward reaction of the R′SH with the second mixed disulphide R″SSR to form R′SSR and R″SH is favoured over a reverse reaction of R″SH with R′SSR back to R″SSR and R′SH; purifying the mixed disulphide R′SSR by a process selected from selective precipitation and chromatography; reacting the purified mixed disulphide R′SSR with a reducing agent to produce the thiol-containing mixture of thiols R′SH and RSH; and separating the mixture of thiols R′SH and RSH to isolate the thiol R′SH, wherein R′SH is 1-D-myo-inosityl-2-deoxy-2-(N-acetyl-L-cysteinyl)amino-α-D-glucopyranoside or mycothiol, the second mixed disulphide R″SSR is 2-thiopyridyl-6-hydroxynaphthyldisulphide, and R″ is a 2-thiopyridyl group.