Raman spectroscopic study of DNA after photosensitive damage caused by hypocrellins A and B

Laser Raman spectroscopy provided the direct evidence for microcosmic photodamage in space structure of DNA molecule. When photosensitive damage was made to space structure of calf thymus DNA by hypocrellins A and B, the Raman characteristic frequencies and the intensities of the bands assigned to various groups of the components of DNA (phosphate backbone deoxyribose and four bases) changed at various degrees. There were not only the strand breakage, but also the breakage of some H bonds and disruption of vertical base base stacking interactions. The photosensitive damage of hypocrellin B on DNA was stronger than that of hypocrellin A on DNA.