(2S)-2-hydrazinyl-3-(4-hydroxy-3-methoxyphenyl)-2-methylpropanoic acid; (2S)-2-Hydrazino-3-(4-hydroxy-3-methoxyphenyl)-2-methylpropanoic acid; Benzenepropanoic acid, a-hydrazino-4-hydroxy-3-methoxy-a-methyl-, (S); 3-O-methylcarbidopa; (S)-2-Hydrazinyl-3-(4-hydroxy-3-methoxyphenyl)-2-methylpropanoic acid; Carbidopa Related Compound A (USP); 3-O-Methylcarbidopa (S - Isomer)