preferred_name: 3-hydroxybutanoate(in) <=> 3-hydroxybutanoate(out)
preferred_name_lc: 3-hydroxybutanoate(in) <=> 3-hydroxybutanoate(out)
label: 3-hydroxybutanoate(in) <=> 3-hydroxybutanoate(out)
label_lc: 3-hydroxybutanoate(in) <=> 3-hydroxybutanoate(out)