Sentence:  As an example, a patient with methyl <WSD>melonic</WSD> acid urea, for whom the enzyme and the liver that converts methyl <WSD>melonic</WSD> acid to succinic acid is not operating, may be well treated by raising the serum level of vitamin B12 1,000-fold. 
Meaning of the word marked with <WSD> tags:  Pertaining to a type of complex heterocyclic triazine related to melem.