A spectroscopic and thermodynamic study of taxol nucleic acid complexes

The interactions of natural and synthetic polynucleotide double strands wit h the antitumor agent paclitaxel and the oncological product "Taxol(R) for Injection Concentrate" (abbreviated as taxol) were examined in diluted aque ous solutions by thermal denaturation profiles (T-m), CD spectra and UV-abs orption measurements. Furthermore, DNA-paclitaxel and -taxol complexes in c ondensed nucleic acid solutions were studied by differential scanning calor imetry. As polynucleotides alternating and homologous poly[d(AT)] and poly[ d(GC)] and calf thymus DNA were used. The results point to stabilizing inte ractions of paclitaxel to AT nucleotides, whereas in the presence of GC bas e pairings no interaction took place. Thereby the interaction to homologous (dA).(dT)-tracts seems to be preferred.