homoprotocatechuic acid

ho·mo·pro·to·cat·e·chu·ic ac·id

(hō'mō-prō'tō-kat'ĕ-chū'ik as'id), (3,4-dihydroxyphenyl)acetic acid; an isomer of homogentisic acid found in urine; a degradation product of l-tyrosine, l-dopa, and hydroxytyramine.