Glucuronoyl esterase which may play a significant role in biomass degradation, as it is considered to disconnect hemicellulose from lignin through the hydrolysis of the ester bond between 4-O-methyl-D-glucuronic acid residues of glucuronoxylans and aromatic alcohols of lignin. a 4-O-methyl-alpha-D-glucuronosyl ester derivative + H2O = 4-O-methyl-alpha-D-glucuronate derivative + an alcohol + H(+) kcat is 115.9 min(-1) with trans-3-phenyl-2-propen-1-yl D-glucopyranosyluronate and 166.4 with 3-phenyl-1-propyl D-glucopyranosyluronate as substrate. Optimum pH is 7.0. Optimum temperature is 55 degrees Celsius. Belongs to the carbohydrate esterase 15 (CE15) family.