Reducing agent for proteins. Prepn: G. V. Lamoureux, G. M. Whitesides, J. Org. Chem. 58, 633 (1993). Enhanced reduction rate in comparison with dithiothreitol, q.v.: R. Singh, G. M. Whitesides, Bioorg. Chem. 22, 109 (1994). Use in reduction of disulfide bonds: D. Winitz et al., J. Biol. Chem. 271, 27645 (1996); A. Brunella, O. Ghisalba, J. Mol. Catal. B 10, 215 (2000); S. Lee, J. P. N. Rosazza, Org. Lett. 6, 365 (2004).