Syntheses and characterization of water-soluble C60-curdlan sulfates for biological applications

Synthesis and characterization of triazol-bridged 6-C60N 3(CH2)n-6- deoxycurdlan sulfates and aza-bridged 6-C60N(CH2)n-6-deoxycurdlan sulfates are discussed. A spacer was introduced into curdlan at the C6 position by the esterification of Br(CH2)COOH with curdlan in the presence of DCC as an activator and in the presence of DMAP as a catalyst in DMSO at room temperature to yield bromoalkyl curdlan ester. The bromoalkylated sample was reacted with a large excess of NaN3 to yield 6-azidoalkylcurdlan ester. The structure of 6-Br(CH2)n-COO-6-deoxycurdlan esters was confirmed by nuclear magnetic resonance (NMR) spectroscopy. The Br analysis after the azidation of 6-bromoal-kylcurdlan esters with NaN3 proved that the transformation of bromine to azide was almost quantitative.