摘要 |
A novel method of covalently coupling polysaccharides to other biopolymers is provided, using an amino-thiol linker represented by formula (1): H2N-[(CH2)m-CHR<1>-CR<2>R<3>-A]q-CHR<4>-(CHR<5>)p-CHR<6>-S-R<7> wherein A is a direct bond or a group having the formula -{Z-(CH2)m-CHR<1>-CHR<2>R<3>}nZ-, m is an integer from 0 to 5; n is an integer from 0 to 3; p is an integer from 0 to 2; q is the integer 0 or 1; R<1> is hydrogen or C1-C6 alkyl, optionally substituted by amino, hydroxyl, carboxyl, C1-C4 alkoxycarbonyl, carbamoyl, mono- or di(C1-C4alkyl)carbamoyl or N-( alpha -carboxyalkyl)carbamoyl, or, if m ≠ 0, R<1> is hydroxyl, amino or peptidylamino; R<2> and R<3> are independently hydrogen or C1-C4 alkyl, or together form an oxo group; R<4> is hydrogen, C1-C4 alkyl, carboxyl, C1-C4 alkoxycarbonyl, carbamoyl, mono- or di(C1-C4 alkyl)carbamoyl or N-( alpha -carboxyalkyl)carbamoyl; R<5> is hydrogen, methyl, hydroxy or C1-C7 acyloxy; R<6> is hydrogen or methyl; R<7> is hydrogen or a thiol-protecting group or a group having the formula -S-CHR<6>-(CHR<5>)p-CHR<4>-[A-CR<2>R<3>-CHR<1>-(CH2)m]q-NH2; and z is imino, methylimino, oxygen or sulphur. |