Welcome to Molecular Photonics Group

Molecular Photonics Group was formed within Laboratory of Laser Spectrometry by Dr. Irina Terenetskaya when she began application of pulsed UV lasers for initiation of provitamin D photoisomerization (which is the first stage of biologically important process of vitamin D synthesis).

reaction scheme UV spectra
Scheme of provitamin D photoisomerization and UV absorption spectra of the photoisomers.
7-DHC - provitamin D, or 7-dehydrocholesterol, Pre – previtamin D, T - tachysterol, L - lumisterol, Tox – toxysterols, D - vitamin D.

That time the main goal was understanding the influence of laser radiation parameters (wavelength, intensity, pulse duration) on the photoreaction kinetics and the photoproduct yield.

Unlike generally accepted chromatographic analysis (HPLC), original spectrophotometric analysis of the multicomponent photoisomer mixture has been developed with due regard to the irreversible photodegradation. In addition adequate mathematical model has been created to calculate the photoreaction kinetics with any UV irradiation source.

Besides the features of provitamin D photochemistry in various reaction media (isotropic solutions, heterogeneous media, liquid crystals, polymer and porous films) were investigated. At the same time, the changes of structure and macroscopic media properties induced by 7-DHC transformations were studied.

Focus of our today activity is the influence of microenvironment on the cis-trans isomerization reaction because it is an ubiquitous photochemical process which forms the fundamental step in many photobiological processes, such as vitamin D synthesis, vision, phototaxis, etc.

One more actual direction is in situ monitoring of biologically active "antirachitic" UV radiation based on the spectral recording of previtamin D photosynthesis in vitro. The new personal UV biodosimeter series VITA-D of vitamin-D synthetic capacity of UV radiation both of sunlight and of artificial sources are designed.