Delivery of Capecitabine by Single-Walled Carbon Nanotube

Application of the zigzag (24, 0) single-walled carbon nanotube (SWCNT) in delivery of carbamate and imine tautomers of capecitabine is investigated via quantum mechanical geometry optimizations followed by chemical shielding calculations. Torsion angle between ribose and cytosine rings is very close to the experimental value in both tautomers. This suggests that relative orientation of these rings is independent of presence of SWCNT. Their carbon nuclei become closer to the tube's internal surface by about 1 angstrom, when going from cytosine ring to aliphatic tail. Their cytosine and ribose rings bend so that fluorine atoms and 2'-OH group form ion-pi interaction with the surface. Calculated binding energies aside from observation of these sorts of interactions in these tautomers can propose SWCNT as their potent delivery tool. Most of the obtained conclusions are manifested in the observed trends for calculated chemical shielding values. They make connections among the reported experimental and computational distributions of chemical shielding values inside SWCNTs.