Esterase involved in the biosynthesis of lignin. Hydrolyzes caffeoylshikimate into caffeate and shikimate. Together with 4-coumarate--CoA ligase (4CL), acts on an alternative reaction for the formation of caffeoyl-CoA and bypasses the second reaction of shikimate O-hydroxycinnamoyltransferase (HST). Accepts also 4-coumaroylshikimate as substrate, but with lower activity. According to PubMed:20345607 and PubMed:22915575, posseses monoacylglycerol O-acyltransferase, monoacylglycerol lipase and lysophospholipase activities in vitro. With the association of ACBP2, may promote the degradation of lysophosphatidylcholine and detoxify the peroxidized membrane in response to cadmium-induced oxidative stress. However these results require additional confirmation in vivo. 5-O-[(E)-caffeoyl]-shikimate + H2O = (E)-caffeate + H(+) + shikimate Interacts with ACBP2. Colocalizes with ACBP2. Expressed in vasculature of roots and leaves, stems, flowers and siliques. By zinc and H(2)O(2). Reduced height and weight of senescent plants due to reduced lignin content. Mutant plants exhibit increased sensitivity to zinc, cadmium and H(2)O(2). Belongs to the AB hydrolase superfamily. Monoacylglycerol lipase family.