.alpha.-Mercaptosuccinic acid 2-Mercaptosuccinic acid 2-Thiomalic acid 70-49-5 Butanedioic acid, mercapto- Malic acid, 2-thio- Mercaptosuccinic acid Monomercaptosuccinic acid NSC7302 Succinic acid, mercapto- Thiomalic acid Usaf ek-p-6297 WLN: SHYVQ1VQ