preferred_name: 2-methyl-cis-aconitate => 2-methyl-trans-aconitate
preferred_name_lc: 2-methyl-cis-aconitate => 2-methyl-trans-aconitate
label: 2-methyl-cis-aconitate => 2-methyl-trans-aconitate
label_lc: 2-methyl-cis-aconitate => 2-methyl-trans-aconitate