Benzoate methanolysis catalyzed by α-cyclosophorohexadecaose isolated from Xanthomonas oryzae

Benzoate methanolysis was accelerated by α-cyclosophorohexadecaose (α-C16), which is a neutral cyclic hexadecaglucoside containing fifteen β-(1 → 2)-linkages and one α-(1 → 6)-linkage. This α-C16, a periplasmic cyclooligosaccharide isolated from rice pathogenic bacteria, Xanthomonas oryzae, enhanced the methanolysis of three different benzoates (vinyl benzoate, phenyl benzoate, and 4-chlorophenyl benzoate) about 69-fold, 24-fold, and 14-fold comparing with control, respectively. A possible intermediate formed during the reaction was detected on MALDI-TOF spectra. Through this study, we suggest that a microbial cyclic glucan, α-C16, can function as a catalytic carbohydrate for the methanolysis of various ester compounds.