Περίληψη
Η μελέτη των θαλάσσιων οργανισμών σαν πηγή βιοδραστικών δευτερογενών μεταβολιτών αποτελεί μία σύγχρονη προέκταση της χημείας φυσικών προϊόντων. Οι κύριοι στόχοι του ερευνητικού αυτού κλάδου είναι η ανακάλυψη (απομόνωση και δομικός χαρακτηρισμός) νέων χημικών ενώσεων που προέρχονται από θαλάσσιους οργανισμούς, η αξιολόγηση των πιθανών βιολογικών ιδιοτήτων τους και η αξιοποίηση τους σε σύγχρονους χώρους εφαρμογής. Η πραγματοποίηση των παραπάνω, συνήθως υποβοηθείται και συνοδεύεται από τη μελέτη και αποσαφήνιση του οικολογικού ρόλου των μεταβολιτών. Το αντικείμενο της παρούσας διδακτορικής διατριβής εντάσσεται στην επιστημονική περιοχή των θαλς
Όλα τα τεκμήρια στο ΕΑΔΔ προστατεύονται d by the genus Laurencia, we have decided to study in depth a number of the species that belong in the “complex” Laurencia and can be found along the Greek coasts, as well as the red alga Asparagopsis armata and its tetrasporiophytic Falkenbergia rufolanosa phase collected in Monte Negro and Salamis island respectively. The organic extracts obtained from the initial treatment of the organisms we processed with chromatographic techniques, mainly High Pressure Liquid chromatography, and yielded a number of metabolites that were characterized on the basis of their spectral data. The red alga Laurencia microcladia collected in Chios island yielded in total 41 metabolites, 11 of which were found to be new natural products, whereas the others with the exception of one compound are found for the first time as constituents of L. microcladia. The new natural products belong in the chemical class of brasilane sesquiterpenes (metabolite 5), bisabolane sesquiterpenes (metabolite 7), non halogenated aromatic sesquiterpenes (metabolites 10 and 11) and halogenated aromatic sesquiterpenes (metabolites 17, 21, 23, 28 - 31). Specimens of L. microcladia collected in Koufonisia and Elafonissos islands resulted in the isolation of one metabolite from each extract that are reported for the first time as constituents of the investigated organism. From specimens of the red alga L. majuscula collected at Ithaki island three metabolites were isolated and characterized. These metabolites are found for the first time as constituents of the investigated organism. From specimens of L. obtusa collected in Chalkidiki through chromatographic separations of the extract one metabolite was isolated. The organic extract of quantities of the red alga L. glandulifera collected in Crete yielded 19 metabolites 13 of which were found to be new natural products, whereas 5 of the rest are reported for the first time as constituents of L. glandulifera. The new natural products are acyclic polyunsaturated metabolites containing a terminal cis ene-yne group (metabolites 47), C15 acetogenin eight membered cyclic ethers with a characteristic terminal cis ene-yne group (metabolites 52 - 55), C15 acetogenin tetrahydrofuran ethers with a characteristic terminal cis ene-yne group (metabolites 56 - 60) and 2 brominated diterpenes (meta phase collected in Monte Negro and Salamis island respectively. The organic extracts obtained from the initial treatment of the organisms we processed with chromatographic techniques, mainly High Pressure Liquid chromatography, and yielded a number of metabolites that were characterized on the basis of their spectral data. The red alga Laurencia microcladia collected in Chios island yielded in total 41 metabolites, 11 of which were found to be new natural products, whereas the others with the exception of one compound are found for the first time as constituents of L. microcladia. The new natural products belong in the chemical class of brasilane sesquiterpenes (metabolite 5), bisabolane sesquiterpenes (metabolite 7), non halogenated aromatic sesquiterpenes (metabolites 10 and 11) and halogenated aromatic sesquiterpenes (metabolites 17, 21, 23, 28 - 31). Specimens of L. microcladia collected in Koufonisia and Elafonissos islands resulted in the isolation of one metabolite from each extract that are reported for the first time as constituents of the investigated organism. From specimens of the red alga L. majuscula collected at Ithaki island three metabolites were isolated and characterized. These metabolites are found for the first time as constituents of the investigated organism. From specimens of L. obtusa collected in Chalkidiki through chromatographic separations of the extract one metabolite was isolated. The organic extract of quantities of the red alga L. glandulifera collected in Crete yielded 19 metabolites 13 of which were found to be new natural products, whereas 5 of the rest are reported for the first time as constituents of L. glandulifera. The new natural products are acyclic polyunsaturated metabolites containing a terminal cis ene-yne group (metabolites 47), C15 acetogenin eight membered cyclic ethers with a characteristic terminal cis ene-yne group (metabolites 52 - 55), C15 acetogenin tetrahydrofuran ethers with a characteristic terminal cis ene-yne group (metabolites 56 - 60) and 2 brominated diterpenes (metabolites 61 and 62). ..............................................................................................................................................................................................................