mal·o·nate 
(mălə-nāt′, -nĭt)
(mălə-nāt′, -nĭt)n.
1. A salt or ester of malonic acid.
2. The dianion with chemical formula CH2(COO)22- that results from removal of the two carboxylic hydrogen ions from malonic acid. In this sense, also called malonate ion.
[MALON(IC ACID) + -ATE.]