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Browsing by Subject "Pseudoceratina purpurea"

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  • Flemmich, Paul (2015)
    There are dozens of bromotyrosine alkaloids extracted from the marine sponge Pseudoceratina purpurea. Bromotyrosines have for example antibacterial, antiviral and antitumor activity in vitro and therefore bromotyrosines are potential drug lead molecules. By far, bromotyrosines have been extracted from different marine sponges of the Verongida order for the use in biological activity research. Collecting marine sponges by scuba diving is neither fast nor ecological and therefore finding an effective synthesis strategy is vital so that the research could continue. One new bromotyrosine, purpurealidin I, was found from the marine sponge Pseudoceratina purpurea in the four year (2010-2014) Marex-project. The aim of this thesis was to synthesize the compound purpurealidin I and its derivatives. Synthesized compounds were tested against hepatitis C and chikungunya viruses. It is important to find new potent drug molecules, because approximately 350 000-500 000 people die from hepatitis C and there is no curative medication for the chikungunya. Purpurealidin I is synthesized from tyrosine and tyramine parts, which will be put together to form an amide bond in the final step of the synthesis. The synthesis of purpurealidin I was not completed during the Master's thesis. However there were two purpurealidin I derivatives and four purpurealidin I tyramine part derivatives that were successfully synthesized. One of the compounds is purpurealidin E, which can be extracted from the sponge Pseudoceratina purpurea. The t-Boc derivative of purpurealidin E was examined against hepatitis C and chikungunya and the compound showed moderate activity against hepatitis C virus, but it wasn't active against chikungunya virus. The original plan to synthesize purpurealidin I is possible, although some reactions and purification of crude products need to be optimized in order to get better yields. For the future research derivatives of the t-Boc derivative of purpurealidin E should be synthesized and studied against hepatitis C virus.
  • Mäki-Lohiluoma, Eero (2015)
    Seas are one of the most biodiverse and species-rich areas on the planet. Many of the underwater species are yet to be found and identified. The marine based drug discovery and the clinical pipeline of marine compounds have increased lately. Thus, there is a strong believe that the marine-derived compounds will provide new pharmaceutical lead compounds. Marine sponges are one of the most studied marine species. Sponges can be found in shallow and deep waters all over the world. Pseudoceratina purpurea is a Verondiga order sponge that is known to be a source of bromotyramines. Bromotyramines are tyramine derivatives that have represented biological activity including cytotoxity, antivirality and antimicrobial effects. Purpurealidin E is a bromotyramine that has been identified from Pseudoceratina purpurea. Purpurealidin E hasn't showed remarkable biological activity by itself, but it can be used as starting point for synthesis of novel bromotyramine derivatives. By forming an amide bond between carboxylic acid and primary amine of purpurealidin E, new bromotyramines can be synthesized. In this master's thesis, purpurealidin E was successfully synthesized. Total amount of 11 novel bromotyramine derivatives were synthesized by amide coupling. Three of the new bromotyramine derivatives and purpurealidin E were purified and their biological activity against hepatitis C virus (HCV) was evaluated. Purpurealidin E did not show any antiviral activity, but all the three compounds showed potential biological activity against HCV. This work can be considered to a continuum to the now ended MAREX project (Exploring Marine Resources for Bioactive Compounds: From Discovery to Sustainable Production and Industrial Applications).