has role 2-butenoic acid monounsaturated fatty acid short-chain fatty acid 3-methylbut-2-enoic acid Senecioic acid Patent:WO2012025270 Patent:CN101391948 A methyl-branched fatty acid that is but-2-enoic acid bearing a methyl substituent at position 3. beta,beta-Dimethacrylic acid 3-Methyl-2-butenoic acid 3-Methylcrotonic acid CHEBI:37127 3-methylbut-2-enoic acid beta-Methylcrotonic acid 3,3-Dimethylacrylic acid beta,beta-Dimethylacrylic acid SENECIC ACID methyl-branched fatty acid plant metabolite alpha,beta-unsaturated monocarboxylic acid