Abstract: Provided is a long chain carboxylic acid imide ester (I) represented by the following general formula (I) ##STR1## wherein W is a divalent long chain hydrocarbon group which may optionally be interrupted by one or more groups each independently selected from the group consisting of an oxygen atom, a sulfur atom, and a group of --N(R.sup.1)-- (R.sup.1 being a lower alkyl group) and X represents a divalent hydrocarbon group which may optionally be substituted, or salts thereof. The above long chain carboxylic acid imide ester or its salts is useful for modifying enzymes or proteins having biological activities to give their derivatives which have, while retaining most of the original biological activities, an extremely prolonged plasma half-life as compared with the proteins and have no antigenecities and can be administered to animals.

Abstract: Provided are novel superoxide dismutase derivatives represented by the following general formula (I) ##STR1## wherein [SOD] is a superoxide dismutase residue derived by removal of two mercapto groups, and W is a divalent long chain hydrocarbon residue which may optionally be interrupted by one or more groups each independently selected from the group consisting of an oxygen atom, a sulfur atom and a group of -N(R)- (R being a lower alkyl group). The SOD derivatives retain most of the enzymatic activities of unmodified SOD and have much longer plasma half-life than unmodified SOD. They are effective for treating various diseases caused by active oxygen species.Also provided are chemical modifiers to prepare the above SOD derivatives.

Abstract: Provided is a long chain carboxylic acid imide ester (I) represented by the following general formula (I) ##STR1## wherein W is a divalent long chain hydrocarbon group which may optionally be interrupted by one or more groups each independently selected from the group consisting of an oxygen atom, a sulfur atom and a group of --N(R.sup.1)-- (R.sup.1 being a lower alkyl group) and X represents a divalent hydrocarbon group which may optionally be substituted, or salts thereof. The above long chain carboxylic acid imide ester or its salts is useful for modifying enzymes or proteins having biological activities to give their derivatives which have, while retaining most of the original biological activities, an extremely prolonged plasma half-life as compared with the proteins and have no antigenecities and can be administered to animals.

Abstract: Provided are novel superoxide dismutase derivatives represented by the following general formula (I) ##STR1## wherein [SOD] is a superoxide dismutase residue derived by removal of two mercapto groups, and W is a divalent long chain hydrocarbon residue which may optionally be interrupted by one or more groups each independently selected from the group consisting of an oxygen atom, a sulfur atom and a group of --N(R)-- (R being a lower alkyl group). The SOD derivatives retain most of the enzymatic activities of unmodified SOD and have much longer plasma half-life than unmodified SOD. They are effective for treating various diseases caused by active oxygen species.Also provided are chemical modifiers to prepare the above SOD derivatives.

Abstract: Novel superoxide dismutase derivatives are provided in which the enzymatic activity of superoxide dismutase capable of decomposing superoxide, a substance harmful to living organisms, is for the most part maintained with the plasma half-life being significantly prolonged as compared with superoxide dismutase itself. They have pharmacological activities such as anti-inflammatory, anti-ischemic and cerebral edema-preventing activities. Also provided are a method of producing such superoxide dismutase derivatives and medicinal uses of them.

Abstract: A bilirubin oxidase derivative resulting from chemical modification of a water-soluble polymeric substance. The chemically modified bilirubin oxidase is useful as a drug for treating jaundice.

Abstract: Provided is a long chain carboxylic acid imide ester (I) represented by the following general formula (I) ##STR1## wherein W is a divalent long chain hydrocarbon group which may optionally be interrupted by one or more groups each independently selected from the group consisting of an oxygen, atom, a sulfur atom, and a group of --N(R.sup.1)-- (R.sup.1 being a lower alkyl group) and X represents a divalent hydrocarbon group which may optionally be substituted, or salt thereof. The above long chain carboxylic acid imide ester or its salts is useful for modifying enzymes or proteins having biological activities to give their derivatives which have, while retaining most of the original biological activities, an extremely prolonged plasma half-life as compared with the proteins and have no antigenecities and can be administered to animals.