preferred_name: 5-methylcytosine + H2O + H(+) <=> thymine + NH4(+)
preferred_name_lc: 5-methylcytosine + h2o + h(+) <=> thymine + nh4(+)
label: 5-methylcytosine + H2O + H(+) <=> thymine + NH4(+)
label_lc: 5-methylcytosine + h2o + h(+) <=> thymine + nh4(+)