Immobilization of 5‐Fluorouridine on Chitosan

The 2′,3′‐O‐levulinic acid derivative 2b of the cancerostatic 5‐fluorouridine as well as its N(3)‐farnesylated nucleolipid 2d were synthesized and coupled to H₂O‐soluble chitosanes of different molecular weight and at various pH values (3.5–5.5) leading to 6 and 7 . In addition, the coumarine fluorophore ATTO‐488 N(9)‐butanoate was bound to the biopolymer by a sequential‐coupling technique to afford 9 and 10 . Moreover, chitosan foils were prepared, to which 2b was coupled. Their degradation by chitosanase (from Streptomyces sp. N174) was studied UV‐spectrophotometrically in a Franz diffusion cell.