Methoxypolyethylene glycol thioester chelate and uses thereof

A method for scavenging free radicals in a cell comprising administering an effective amount of the compound of formula (I),

• wherein one R1 is formula (II),
• each of the remaining R1 is selected from formula (II) or from the group consisting of —CH2COOH, —CH2COO−Na+, —CH2COO−Ca++/2, —CH2COOCH3, —CH2COOC2H5, and —CH2COOC3H7;
• a is 0 to 6;
• each b is independently 0 to 18;
• each c is independently 3 to 10;
• and
• d is independently 1 to 3,
• wherein the free radicals are selected from the group consisting of peroxides, superoxide anions, hydroxyl radical, and nitric oxide.

A method for inhibiting catalysis of free radical oxidant formation by heavy metals in a cell comprising administering an effective amount of the compound of formula (I),

• wherein one R1 is formula (II),
• each of the remaining R1 is selected from formula (II) or from the group consisting of —CH2COOH, —CH2COO−Na+, —CH2COO−Ca++/2, —CH2COOCH3, —CH2COOC2H5, and —CH2COOC3H7;
• a is 0 to 6;
• each b is independently 0 to 18;
• each c is independently 3 to 10;
• and
• d is independently 1 to 3;
• wherein the free radical oxidant is selected from the group consisting of peroxides, superoxide anions, hydroxyl radical, and nitric oxide, and
• wherein the compound is capable of forming chelates with metals.