Abstract: A method for purifying a polyethylene glycol compound represented by formula [1], including a Step (A) of dissolving the compound represented by formula [1] in an organic solvent having a Hildebrand solubility parameter of 8 to 10 (cal/cm3)1/2 to obtain a solution, and a Step (B) of mixing the solution with 0.1 to 1 part by mass of an adsorbent made from a hydrotalcite having a specific surface area of 50 to 200 m2/g with respect to 1 part by mass of the compound of the formula [1] to prepare a slurry, where Z, Y1, Y2, A, Polymer, X, a, b, l and m are as defined herein.

Abstract: A method for purifying a branched polyethylene glycol, which includes adding, to a branched polyethylene glycol compound represented by the following formula [1] and having a weight average molecular weight of 40000 or more: where Z, Y1, Y2, A, Polymer, l, m and b are as defined herein, at least one solid acid selected from magnesium silicate, aluminum silicate, and aluminum magnesium silicate and having a specific surface area of 50 to 250 m2/g in the presence of an aprotic organic solvent to obtain a mixture; stirring the mixture; and subsequently separating the solid acid.

Abstract: The invention provides a modified bio-related substance that shows further prolonged half-life in blood and further improved stability in the blood of living organisms. In particular, the invention provides a conjugate of a block polymer and a bio-related substance, which conjugate is represented by the following formula (I), wherein each symbol is as described herein.

Abstract: The invention provides a high-molecular-weight polyethylene glycol derivative that does not cause vacuolation of cells. The degradable polyethylene glycol derivative is represented by the following formula (1): wherein m is 1-7, n1 and n2 are each independently 45-682, p is 1-4, R is an alkyl group having 1-4 carbon atoms, Z is an oligopeptide with 2-8 residues composed of neutral amino acids excluding cysteine, Q is a residue of a compound having 2-5 active hydrogens, X is a functional group capable of reacting with a bio-related substance, and L1, L2, L3, L4 and L5 are each independently a single bond or a divalent spacer.

Abstract: The invention provides a bio-related substance bonded to a high-molecular-weight polyethylene glycol derivative that does not cause vacuolation of cells. The bio-related substance bonded to a degradable polyethylene glycol derivative is represented by the formula (A): wherein m is 1-7, n1 and n2 are each independently 45-682, p is 1-4, R is an alkyl group having 1-4 carbon atoms, Z is an oligopeptide with 2-8 residues composed of neutral amino acids excluding cysteine, Q is a residue of a compound having 2-5 active hydrogens, D is the bio-related substance, L1, L2, L3, L4 and L5 are each independently a single bond or a divalent spacer, and y is 1-40.

Abstract: A purification method of a polyethylene glycol compound having one carboxyl group. In the method, an aqueous solution of the compound having a pH of 8 to 11 is prepared, the aqueous solution and a mixed organic solvent are mixed at a temperature of 15° C. or more and 50° C. or less and the mixture is separated into an organic layer and an aqueous layer. In the mixed organic solvent, a ratio of solvent I is from 25 to 60% by mass, and a ratio of solvent II is from 75 to 40% by mass. Solvent I is a hydrocarbon, solvent II is a halogenated hydrocarbon, a mixing ratio Y (organic solvent I/organic solvent II), a temperature T (° C.) at mixing and a weight average molecular weight M of the compound satisfy a relationship of 3.11×10?6M+0.084?Y?0.0135T??1.77×10?6M+0.404.

Abstract: A purification method of a polyethylene glycol compound having one carboxyl group. In the method, an aqueous solution of the compound having a pH of 8 to 11 is prepared, the aqueous solution and a mixed organic solvent are mixed at a temperature of 15° C. or more and 50° C. or less and the mixture is separated into an organic layer and an aqueous layer. In the mixed organic solvent, a ratio of solvent I is from 25 to 60% by mass, and a ratio of solvent II is from 75 to 40% by mass. Solvent I is a hydrocarbon, solvent II is a halogenated hydrocarbon, a mixing ratio Y (organic solvent I/organic solvent II), a temperature T (° C.) at mixing and a weight average molecular weight M of the compound satisfy a relationship of 3.11×10?6M+0.084?Y?0.0135T??1.77×10?6M+0.404.

Abstract: A multi-arm polyethylene glycol derivative having a narrow molecular weight distribution represented by the formula (1): wherein, L represents a group selected from a linear or branched alkylene, arylene, or cycloalkylene group having two or more carbon atoms and combinations thereof, which may have an ether bond in a chain; X represents a dehydroxylation residue of a linear sugar alcohol having 5 or 7 carbon atoms; m is the number of polyethylene glycol chains bonded to X and represents 4 or 6; n is the average addition molar number of oxyethylene groups and represents an integer of 3 to 600; Y represents a single bond or an alkylene group as further defined herein; and Z represents a chemically reactive functional group.

Abstract: A multi-arm polyethylene glycol derivative having a narrow molecular weight distribution represented by the formula (1): wherein, L represents a group selected from a linear or branched alkylene, arylene, or cycloalkylene group having two or more carbon atoms and combinations thereof, which may have an ether bond in a chain; X represents a dehydroxylation residue of a linear sugar alcohol having 5 or 7 carbon atoms; m is the number of polyethylene glycol chains bonded to X and represents 4 or 6; n is the average addition molar number of oxyethylene groups and represents an integer of 3 to 600; Y represents a single bond or an alkylene group as further defined herein; and Z represents a chemically reactive functional group.

Abstract: A method for purifying a polyethylene glycol compound having one amino group, which includes (A) preparing an aqueous solution of the compound having a pH of 1 to 5, (B) an extracting step of mixing the aqueous solution with a mixed organic solvent to cause layer separation into organic and aqueous layers, wherein a ratio of an organic solvent I is 25 to 65% by mass and a ratio of an organic solvent II is 75 to 35% by mass, the organic solvent I is selected from an aromatic hydrocarbon and an ester, the organic solvent II is a halogenated hydrocarbon, and a mixing ratio Y of I to II, temperature T (° C.) at mixing, and molecular weight M of the compound satisfy the following relationship: 1.9×10?6M+0.09?Y?0.015T??1.4×10?6M+0.44 and (C) recovering the compound from the aqueous layer.

Abstract: Provided is a multi-arm polyethylene glycol derivative having a narrow molecular weight distribution. A multi-arm polyethylene glycol derivative represented by the formula (1): m[Z—YnCH2CH2OX—O-L-O—XOCH2CH2nY—Z]m??(1) wherein, L represents a group selected from a linear or branched alkylene, arylene, or cycloalkylene group having two or more carbon atoms and combinations thereof, which may have an ether bond in a chain; X represents a dehydroxylation residue of a linear sugar alcohol having 5 or 7 carbon atoms; m is the number of polyethylene glycol chains bonded to X and represents 4 or 6; n is the average addition molar number of oxyethylene groups and n represents an integer of 3 to 600; Y represents a single bond or an alkylene group which may have an ester bond, a urethane bond, an amide bond, an ether bond, a carbonate bond, a secondary amino group, a urea bond, a thioether bond or a thioester bond in a chain or at an end; and Z represents a chemically reactive functional group.

Abstract: A method for purifying a polyethylene glycol compound having one amino group, which includes (A) preparing an aqueous solution of the compound having a pH of 1 to 5, (B) an extracting step of mixing the aqueous solution with a mixed organic solvent to cause layer separation into organic and aqueous layers, wherein a ratio of an organic solvent I is 25 to 65% by mass and a ratio of an organic solvent II is 75 to 35% by mass, the organic solvent I is selected from an aromatic hydrocarbon and an ester, the organic solvent II is a halogenated hydrocarbon, and a mixing ratio Y of I to II, temperature T (° C.) at mixing, and molecular weight M of the compound satisfy the following relationship: 1.9×10?6M+0.09?Y?0.015T??1.4×10?6M+0.44 and (C) recovering the compound from the aqueous layer.

Abstract: Provided is a multi-arm polyethylene glycol derivative having a narrow molecular weight distribution. A multi-arm polyethylene glycol derivative represented by the formula (1): m[Z—Yn?CH2CH2O??X—O-L-O—X??OCH2CH2?nY—Z]m??(1) wherein, L represents a group selected from a linear or branched alkylene, arylene, or cycloalkylene group having two or more carbon atoms and combinations thereof, which may have an ether bond in a chain; X represents a dehydroxylation residue of a linear sugar alcohol having 5 or 7 carbon atoms; m is the number of polyethylene glycol chains bonded to X and represents 4 or 6; n is the average addition molar number of oxyethylene groups and n represents an integer of 3 to 600; Y represents a single bond or an alkylene group which may have an ester bond, a urethane bond, an amide bond, an ether bond, a carbonate bond, a secondary amino group, a urea bond, a thioether bond or a thioester bond in a chain or at an end; and Z represents a chemically reactive functional group.