FTIR investigation of the interaction of tumor cells treated with caffeic acid and chlorogenic acid

Fourier transform infrared spectra of U937 cells treated with chlorogenic a cid (CGA) and caffeic acid (CA) for 1, 6, 12 and 24h were recorded and anal yzed. Some considerable changes in the ratio of the absorbance of the bands at 2960 and 1855 cm(-1) (D-2960/D-2855) and the ratio of the integrated ar eas of the absorption at 1540 and 1086 cm(-1) (A(1510)/A(1086)) of the spec tra of the tumor cells were observed for different times of incubation and drug concentrations. The cells treated for 6h have the highest D-2960/D-285 5 and lowest A(1540)/A(1086) ratios. CGA has stronger interaction with U937 than that with CA. These two phenolic acids could interact with both prote ins and nucleic acids of tumor cells. And these changes in the spectra of c ells could be explained as the degeneration of the protein and nucleic acid s in cells. (C) 2000 Elsevier Science B.V. All rights reserved.