The interaction properties and mechanism of host-guest of cucurbit[6, 7, 8]urils with adefovir bis(L-phenylalanine propyl) ester prodrug have been investigated by ¹H NMR technique, fluorescence spectrophotometry and IR spectroscopy. The experimental results revealed that cucurbit[n]urils can form host-guest complex with adefovir prodrug, and phenylalanine residue of guest FH-1 is located in the shielding zone of the cavity of Q[6, 7, 8], other parts of FH-1 is located at the deshielding portal of the host. Fluorometric analysis revealed that FH-1 can form inclusion complex with Q[6], Q[7], Q[8] with a ratio of 1∶1 or 2∶1, 1∶1 or 3∶1 and 2∶1, respectively. Hygroscopic stability studies indicated that moisture stability of host-guest complex is significantly enhanced. Anti-HBV study showed that host-guest complex significantly increases anti-HBV activity and selective index of the adefovir prodrug.

Key words: adefovir, L-amino acid, cucurbit[n]uril, host-guest complex