Author(s)

Yoshihiro Mizukami

Faculty of Liberal Arts and Education, Shiga University, Otsu, Japan.

Photochemical reactions of microcystin-LR, a toxic compound produced by some blue green algae, were investigated. Ultraviolet absorption of microcystin-LR was assessed. Time-dependent density functional theory (TDDFT) calculations indicated that absorption peak at 238 nm was mainly due to excitation of electrons from the linear chain structure Adda of microcystin-LR. Irradiation of microcystin-LR with UV light resulted in the reduction of the 238 nm absorption peak and the appearance of a new peak at 300 nm. Density functional theory (DFT) and TDDFT calculations with a model molecule suggested that this 300 nm peak was due to tricyclo-Adda microcystin-LR, an intermediate in photochemical reactions of microcystin-LR. Analysis of the rate of this photochemical reaction showed that it was a first order reaction.

Microcystin-LR, UV Irradiation, UV Spectra, DFT Calculations, Photochemical Reactions

Mizukami, Y. (2016) Photochemical Reactions of Microcystin-LR Following Irradiation with UV Light. Open Journal of Physical Chemistry, 6, 79-85. doi: 10.4236/ojpc.2016.64008.