Syntheses of modified 2-chloro-4-nitrophenyl β-maltopentaosides as useful substrates for assay of human alpha amylase
摘要:
Twenty-three novel 2-chloro-4-nitrophenyl beta-D-maltopentaosides modified at the 6(5) and/or 4(5) position were synthesized as substrates for human alpha amylase. Two human alpha amylases hydrolyzed 6(5)-deoxy-6(5)-, 6(5)-O-, and 4(5),6(5)-di-O-substituted derivatives at essentially a single D-glucosidic linkage, but 4(5),6(5)-O-bridged and 4(5)-O-substituted derivatives were hydrolyzed at two or more linkages. The amylases displayed smaller K(m) values for the compounds having hydrophobic modifications. In these derivatives, 2-chloro-4-nitrophenyl O-(6-bromo-6-deoxy-alpha-D-glucopyranosyl)-(1 --> 4)-tris[O-alpha-D-glucopyranosyl-(1 --> 4)]-beta-D-glucopyranoside (10), 2-chloro-4-nitrophenyl O-(6-azido-6-deoxy-alpha-D-gluco-pyranosyl)-(1 --> 4)-tris[O-alpha-D-glucopyranosyl-(1 --> 4)]-beta-D-glucopyranoside (19), and 2-chloro-4-nitrophenyl O-[6-O-(N-isopropyl)carbamoyl-alpha-D-glucopyranosyl]-(1 --> 4)-tris[O-alpha-D-glucopyranosyl-(1 --> 4)]-beta-D-glucopyranoside (30), which were rapidly hydrolyzed by the two amylases at a limited position at an approximately equal rate, were shown to be very useful blocked-type substrates for assay of human alpha amylase.
Syntheses of modified 2-chloro-4-nitrophenyl β-maltopentaosides as useful substrates for assay of human alpha amylase
摘要:
Twenty-three novel 2-chloro-4-nitrophenyl beta-D-maltopentaosides modified at the 6(5) and/or 4(5) position were synthesized as substrates for human alpha amylase. Two human alpha amylases hydrolyzed 6(5)-deoxy-6(5)-, 6(5)-O-, and 4(5),6(5)-di-O-substituted derivatives at essentially a single D-glucosidic linkage, but 4(5),6(5)-O-bridged and 4(5)-O-substituted derivatives were hydrolyzed at two or more linkages. The amylases displayed smaller K(m) values for the compounds having hydrophobic modifications. In these derivatives, 2-chloro-4-nitrophenyl O-(6-bromo-6-deoxy-alpha-D-glucopyranosyl)-(1 --> 4)-tris[O-alpha-D-glucopyranosyl-(1 --> 4)]-beta-D-glucopyranoside (10), 2-chloro-4-nitrophenyl O-(6-azido-6-deoxy-alpha-D-gluco-pyranosyl)-(1 --> 4)-tris[O-alpha-D-glucopyranosyl-(1 --> 4)]-beta-D-glucopyranoside (19), and 2-chloro-4-nitrophenyl O-[6-O-(N-isopropyl)carbamoyl-alpha-D-glucopyranosyl]-(1 --> 4)-tris[O-alpha-D-glucopyranosyl-(1 --> 4)]-beta-D-glucopyranoside (30), which were rapidly hydrolyzed by the two amylases at a limited position at an approximately equal rate, were shown to be very useful blocked-type substrates for assay of human alpha amylase.