The suffix -oate is the IUPAC nomenclature used in organic chemistry to form names of compounds formed from carboxylic acids. They are of two types:

• Formed by replacing the hydrogen atom in the –COOH by some other radical, usually an alkyl or aryl radical forming an ester. For example, methyl benzoate is a molecular compound with the structure C₆H₅–CO–O–CH₃, and its condensed structural formula usually written as C₆H₅COOCH₃.
• Formed by removing the hydrogen atom in the –COOH, producing an anion, which joins with a cation forming a salt. For example, the sodium benzoate is an ionic compound with the structure C₆H₅–CO–O⁻ Na⁺, and its condensed structural formula usually written as C₆H₅CO₂Na.

The suffix comes from "-oic acid".

The most common examples of compounds named with the "oate" suffix are esters, like ethyl acetate, CH
₃COOCH
₂CH
₃.

References

• International Union of Pure and Applied Chemistry Organic Chemistry Division Commission on Nomenclature of Organic Chemistry (1995). Panico, Robert; Powell, Warren H.; Richer, Jean-Claude (eds.). A Guide to IUPAC Nomenclature of Organic Compounds: Recommendations 1993 (including revisions, published and hitherto unpublished, to the 1979 edition of Nomenclature of Organic Chemistry) (2nd ed.). Oxford: Blackwell Scientific Publications. ISBN 9780632034888.
• International Union of Pure and Applied Chemistry Division of Chemical Nomenclature and Structure Representation (2014). Favre, Henri A.; Powell, Warren H. (eds.). Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013. Cambridge: Royal Society of Chemistry. doi:10.1039/9781849733069. ISBN 978-1-84973-306-9.