Cysteine prodrug. Prepn: J. A. Maclaren, Aust. J. Chem. 21, 1891 (1968); T. K"omives, Org. Prep. Proced. Int. 21, 251 (1989). Crystal structure: N. Ramasubbu, R. Parthasarathy, Int. J. Pept. Protein Res. 34, 153 (1989). Precursor for cysteine and use as glutathione biosynthesis stimulant: J. M. Williamson et al., Proc. Natl. Acad. Sci. USA 79, 6246 (1982); in chicks: T. K. Chung et al., J. Nutr. 120, 158 (1990). Toxicity: R. D. White et al., Acute Toxic. Data 1, 164 (1992); R. D. White et al., Toxicol. Lett. 69, 15 (1993). Clinical evaluation in HIV infection: G. Giorgi et al., Curr. Ther. Res. 52, 461 (1992); in asymptomatic HIV infection: R. C. Kalayjian et al., J. Acquir. Immune Defic. Syndr. 7, 369 (1994). HPLC determn in plasma: L. W. Webb et al., J. Chromatogr. B 654, 257 (1994).