Browsing by Subject "TRITERPENOIDS"

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  • Räsänen, Riikka-Marjaana; Hieta, Juha-Pekka; Immanen, Juha; Nieminen, Kaisa; Haavikko, Raisa; Yli-Kauhaluoma, Jari; Kauppila, Tiina J. (2019)
    Desorption atmospheric pressure photoionization (DAPPI) is an ambient mass spectrometry (MS) technique that allows the analysis of both polar and nonpolar compounds directly from the surfaces of various sample types. Here, DAPPI was used to study the chemical profiles in different parts of birch and alder tree barks. Four distinct fractions of Betula pendula (silver birch) bark were collected from three different developmental stages of the stem, after which the chemical profiles of the different tissue types were measured. Of special interest were triterpenoids, a class of important defensive substances, which are found in the bark of the silver birch. Additionally, the chemical profiles of lenticels and the surrounding surfaces in the phellem of B. pendula (silver birch), Alnus glutinosa (black alder), and Alnus incana (gray alder) were screened with DAPPI. Another ambient MS technique, laser ablation atmospheric pressure photoionization (LAAPPI), was further used for the mass spectrometry imaging of lenticels on the B. pendula phellem. All the studied birch bark fractions showed individual chemical profiles in DAPPI. The mass spectra from the young apical stem and the transition zone resembled each other more than the mature stem. Instead, the phellem was found to contain a high amount of triterpenoids in all the developmental stages of the stem. The most intense peaks in the DAPPI mass spectra of the birch bark fractions were those of betulin and lupeol. Betulinic and betulonic acid peaks were intense as well, and these compounds were detected especially in the lenticels of the tree samples.
  • Kolsi, Laura E.; Leal, Ana S.; Yli-Kauhaluoma, Jari; Liby, Karen T.; Moreira, Vânia M. (2018)
    Low 5-year survival rates, increasing incidence, as well as the specific challenges of targeting pancreatic cancer, clearly support an urgent need for new multifunctional drugs for the prevention and treatment of this fatal disease. Natural products, such as abietane-type diterpenoids, are widely studied as promiscuous anticancer agents. In this study, dehydroabietic oximes were identified as potential compounds to target pancreatic cancer and cancer-related inflammation. The compounds inhibited the growth of human pancreatic cancer Aspc-1 cells with IC50 values in the low micromolar range and showed anti-inflammatory activity, measured as the inhibition of nitric oxide production, an important inflammatory mediator in the tumour microenvironment. Further studies revealed that the compounds were able to induce cancer cell differentiation and concomitantly downregulate cyclin D1 expression with upregulation of p27 levels, consistent with cell cycle arrest at the G1 phase. Moreover, a kinase profiling study showed that one of the compounds has isoform-selective, however modest, inhibitory activity on RSK2, an AGC kinase that has been implicated in cellular invasion and metastasis.
  • Alonso Serra, Juan Antonio; Safronov, Omid; Lim, Kean-Jin; Fraser-Miller, Sara; Blokhina, Olga Borisovna; Campilho, Ana; Chong, Sun-Li; Fagerstedt, Kurt Valter; Haavikko, Raisa Hannele; Helariutta, Ykä; Immanen, Juha Jouko Matias; Kangasjärvi, Jaakko Sakari; Kauppila, Tiina J.; Lehtonen, Mari; Ragni, Laura; Rajaraman, Sitaram; Räsänen, Riikka-Marjaana; Safdari, Pezhman; Tenkanen, Tiina Maija; Yli-Kauhaluoma, Jari Tapani; Teeri, Teemu Heikki; Strachan, Clare Joanna; Nieminen, Kaisa; Salojärvi, Jarkko Tapani (2019)
    Tree bark is a highly specialized array of tissues that plays important roles in plant protection and development. Bark tissues develop from two lateral meristems; the phellogen (cork cambium) produces the outermost stem-environment barrier called the periderm, while the vascular cambium contributes with phloem tissues. Although bark is diverse in terms of tissues, functions and species, it remains understudied at higher resolution. We dissected the stem of silver birch (Betula pendula) into eight major tissue types, and characterized these by a combined transcriptomics and metabolomics approach. We further analyzed the varying bark types within the Betulaceae family. The two meristems had a distinct contribution to the stem transcriptomic landscape. Furthermore, inter- and intraspecies analyses illustrated the unique molecular profile of the phellem. We identified multiple tissue-specific metabolic pathways, such as the mevalonate/betulin biosynthesis pathway, that displayed differential evolution within the Betulaceae. A detailed analysis of suberin and betulin biosynthesis pathways identified a set of underlying regulators and highlighted the important role of local, small-scale gene duplication events in the evolution of metabolic pathways. This work reveals the transcriptome and metabolic diversity among bark tissues and provides insights to its development and evolution, as well as its biotechnological applications.