1081-71-6 3-Methoxy-4-hydroxyphenylpyruvic acid 4- Hydroxy-3-methoxy-alpha-oxobenzenepropanoic acid 4-HYDROXY-3-METHOXYPHENYL)PYRUVIC ACID 4-Hydroxy-3-methoxyphenylpyruvic acid Hmppa cpd NSC 302091 Vanilpyruvic acid