Spectroscopic analysis of carotenoids in living organisms
Author: Bc. Anna RosenkrancováSupervisor: Doc. RNDr. Peter Mojzeš, CSc.
Consultants: Jana Pilátová
Type: Master
Annotation: Carotenoids are one of the most common biomolecules in living organisms from bacteria to mammals. Among their various functions, carotenoids act as a part of light-harvesting antennas in the chloroplasts of plants and algae, the photosensory pigments necessary for our vision, or important antioxidants. Depending on their function, their location in cells and subcellular compartments varies. Carotenoids have an extremely intense signal of Raman scattering without resonance due to very efficient Raman cross-sections of their conjugated bonds. Furthermore, there is a discrepancy in the literature regarding their spectral properties attributed to fluorescence in biological samples, while physically oriented publications exclude fluorescence due to the forbidden energy transitions necessary for the excitation of valence electrons. Besides, there is no widespread awareness of the origin of "green autofluorescence" in many organisms, including human cell lines and tissue samples, where it is even used as “a proxy” in the aging or progression of pathological findings. Our observations to date suggest that the molecular basis of these as yet uninterpreted data is the presence of carotenoids, whose spectral properties vary depending on the chemical environment, especially the polarity of the solvent, which will be the subject of this work. The thesis project should aim to systematical revision of the spectral behavior of carotenoids as pure substances and also directly in vivo and in situ in living organisms. Working material and experimental equipment in the form of Raman microscope, Raman spectroscope, fluorimeter and FLIM microscopy are available. The diploma thesis will be a part of the GAČR grant project that will bring a financial benefit to the student. The results of the work will be presented at conferences and published as a scientific article.