(S)-2-Amino-4,4-dichlorobutanoic acid 10139-00-1 11043-31-5 Antibiotic U 10923 Armentomycin BUTANOIC ACID, 2-AMINO-4,4-DICHLORO-, (S)- Butyric acid, 2-amino-4,4-dichloro-, L- (8CI) L-2-Amino-4,4-dichlorobutyric acid U-10923 alpha,alpha-Dichloro-L-butyrine