In enzymology, a glucarolactone O-hydroxycinnamoyltransferase (EC 2.3.1.132) is an enzyme that catalyzes the chemical reaction

sinapoyl-CoA + glucarolactone CoA + O-sinapoylglucarolactone

Thus, the two substrates of this enzyme are sinapoyl-CoA and glucarolactone, whereas its two products are CoA and O-sinapoylglucarolactone.

This enzyme belongs to the family of transferases, specifically those acyltransferases transferring groups other than aminoacyl groups. The systematic name of this enzyme class is sinapoyl-CoA:glucarolactone O-(hydroxycinnamoyl)transferase.

• Strack D, Keller H, Weissenbock G (1987). "Enzymatic-synthesis of hydroxycinnamic acid-esters of sugar acids and hydroaromatic acids by protein preparations from rye (Secale cereale) primary leaves". J. Plant Physiol. 131: 61–73.