Conjugates

A conjugate of formula (I), or a pharmaceutical composition comprising the conjugate of formula (I):

• wherein:
• —RA and —RB are each independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, cycloalkylalkyl, alkanoyl and aralkanoyl;
• or —RA and —RB together with —C(RC1)(RC2) form a 6-membered ring, where
• —RC1 is independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl and cycloalkylalkyl, and
• —RC2 is independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, cycloalkylalkyl, alkoxy, alkenoxy, alkynoxy, aralkoxy and cycloalkylalkoxy, or
• —RC1 and —RC2 are together oxo (═O);
• —RT1 and —RT2 are each independently hydrogen or alkyl;
• —R1 and —R2 are each independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl and cycloalkylalkyl;
• —R3 is hydrogen or alkyl;
• -D- is C2-4 alkenylene or C1-4 alkylene, where the alkenylene or alkylene is optionally substituted with alkyl or halo;
• —X— is a covalent bond, —N(R4)—, —O—, —S—, or —Se—, where —R4 is hydrogen or alkyl;
• -L- is a linker or a covalent bond;
• and
• A- is an active agent for delivery, and comprises a dye, a small drug, a polypeptide, a polynucleotide or a polysaccharide;
• and salts, solvates and protected forms thereof.