Proceedings of the Estonian Academy of Sciences. Chemistry最新文献

{"title":"On the mechanism of reactive oxygen species generation in tumour cells subjected to the phototoxic action of haematoporphyrin derivative: effect of heating; 14–37","authors":"L. Chekulayeva, I. Shevchuk, V. Chekulayev, E. Oginskaya","doi":"10.3176/chem.2007.1.02","DOIUrl":"https://doi.org/10.3176/chem.2007.1.02","url":null,"abstract":"The main aims of the study were: (1) to enrich the existing knowledge on the mechanism of H2O2, superoxide (O2 - ), and protein peroxides (PPO) formation in tumour cells subjected to photodynamic therapy (PDT) with haematoporphyrin derivative (HPD) and (2) to explain the stimulatory effect of heat stress on the generation of O 2 - (a precursor of H2O2 and a very reactive hydroxyl radical) in HPD-PDT-treated cells. Experiments were performed on Ehrlich ascites carcinoma (EAC) cells, which were loaded with HPD in phosphate-buffered saline and then irradiated with red light at 630 nm in the same buffer. Studies showed that photoexcited HPD itself, i.e. in the absence of photooxidizable biomolecules, is a poor source of H 2O2 and oxygen radicals, and that in tumour cells subjected to PDT with HPD the generation of H 2O2 and O2 - could be largely explained by (i) photooxidation of certain cellular constituents (NAD(P)H), (ii) an increase in the activity of xanthine oxidase (XOD), and (iii) a photodamage to mitochondria. Besides, it was found that in cellular proteins the HPD-photosensitized oxidation of aromatic amino acids is responsible for the generation of H2O2 and PPO. Our data suggest that upon HPD-PDT the mild hyperthermia (ca 44 °C) produced by photoirradiation may enhance its tumouricidal effect via the stimulation of O 2 - formation; it was found that a rise in the temperature from 30 to 44 °C strongly (by ca 2.5-fold) enhanced the generation of O2 - in EAC cells, which correlated well with an increase in the rate of their HPD-photosensitized killing. Studies showed that the intensification of O 2 - formation is mediated by the stimulatory effects of heating on the activity of XOD as well as the production of this radical by the respiratory chain of mitochondria. Nevertheless, the obtained results indicate that severe hyperthermia (at temperatures > 45 °C) could induce, contrary to mild hyperthermia, a reduction in the efficiency of HPD-PDT due to suppression of the activity of XOD in tumour cells.","PeriodicalId":20551,"journal":{"name":"Proceedings of the Estonian Academy of Sciences. Chemistry","volume":"30 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75741019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Column study of the leaching and degradation of anionic surfactants in oil-polluted soil; 87–97","authors":"A. Selberg, Jana Budashova, T. Tenno","doi":"10.3176/chem.2007.2.04","DOIUrl":"https://doi.org/10.3176/chem.2007.2.04","url":null,"abstract":"The study was carried out with coarse-grained and fine sandy oil-polluted soils in column tests and the soil was treated with the bioremediation agent SR-100. The concentrations of the hydrocarbons and anionic surfactants were determined in the fractions of soil from the column. In the experiments with the coarse-grained soil the highest concentration of residual surfactants (up to 122 mg/kg) was found in the column with unpolluted soil. The distribution of the residual surfactants was even for the fine sandy soil sample s and it was slightly higher for the mixture of polluted soil and CaCO3. The results indicated degradation of surfactants in the polluted soil but the degradation did not completely remove the surfactants and leaching from soil was observed.","PeriodicalId":20551,"journal":{"name":"Proceedings of the Estonian Academy of Sciences. Chemistry","volume":"70 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75096042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis of substituted cyclopentanones from 2-oxabicyclo[3.3.0]oct-6-en-3-one; 3–13","authors":"R. Aav, T. Kanger, M. Lopp, T. Pehk","doi":"10.3176/chem.2007.1.01","DOIUrl":"https://doi.org/10.3176/chem.2007.1.01","url":null,"abstract":"","PeriodicalId":20551,"journal":{"name":"Proceedings of the Estonian Academy of Sciences. Chemistry","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89219840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Some important aspects of sterol analysis of vegetable oils; 59–66","authors":"J. Jõudu, P. Lääniste, E. Mäeorg, U. Mäeorg","doi":"10.3176/chem.2007.2.01","DOIUrl":"https://doi.org/10.3176/chem.2007.2.01","url":null,"abstract":"","PeriodicalId":20551,"journal":{"name":"Proceedings of the Estonian Academy of Sciences. Chemistry","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87371522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of the method and duration of extraction on the content of biologically active compounds in herbal teas; 53–56","authors":"I. Kuznetsova, A. Raal","doi":"10.3176/chem.2007.1.04","DOIUrl":"https://doi.org/10.3176/chem.2007.1.04","url":null,"abstract":"","PeriodicalId":20551,"journal":{"name":"Proceedings of the Estonian Academy of Sciences. Chemistry","volume":"89 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76275545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monitoring of oil products and hazardous substances in Estonian surface water bodies; 75–86","authors":"R. Aps, K. Kuningas, O. Roots, A. Talvari","doi":"10.3176/chem.2007.2.03","DOIUrl":"https://doi.org/10.3176/chem.2007.2.03","url":null,"abstract":"","PeriodicalId":20551,"journal":{"name":"Proceedings of the Estonian Academy of Sciences. Chemistry","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90703853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chemistry of the isocyanides and their multicomponent reactions, including their libraries – the initiatives of Ivar Ugi; 98–102","authors":"M. Veiderma","doi":"10.3176/chem.2007.2.05","DOIUrl":"https://doi.org/10.3176/chem.2007.2.05","url":null,"abstract":"","PeriodicalId":20551,"journal":{"name":"Proceedings of the Estonian Academy of Sciences. Chemistry","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81556262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Treatment of sulphate containing yeast wastewater in an anaerobic sequence batch reactor; 38–52","authors":"M. Krapivina, Tõnu Kurissoo, Viktoria Blonskaja, S. Zub, R. Vilu","doi":"10.3176/chem.2007.1.03","DOIUrl":"https://doi.org/10.3176/chem.2007.1.03","url":null,"abstract":"Anaerobic mesophilic fermentation of sulphate containing yeast industry wastewaters at laboratory scale with anaerobic sequence batch reactors (ASBR) was studied. Three different treat- ment schemes were investigated - ASBR with and without a polymeric filler and coupled micro- aerophilic/anaerobic SBR (CSBR). The optimal concentration of sludge (total solids 17.3 g L -1 ) in the reactor and the optimal reaction time (22 h) were determined. It was shown that in the case of ASBR efficient treatment characterized by chemical oxygen demand (COD) removal of 75-82% took place at volume loading rates up to 7.7-8.0 kgCOD m -3 d -1 and at COD/(SO4) 2- ratio 8.0. In optimal conditions the methane content of the biogas was 60%. The best results for sulphate removal (99%) were achieved in the CSBR with the concentration of sulphide in the reactor effluent being a bout 10 mg L -1 . Decreasing treatment efficiency after a long-time exploitation of these reactors occurred as a result of the formation of insoluble sediment (presumably CaCO 3 and Ca3(PO4)2).","PeriodicalId":20551,"journal":{"name":"Proceedings of the Estonian Academy of Sciences. Chemistry","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75073957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variation in the composition of the essential oil of Valeriana officinalis L. roots from Estonia; 67–74","authors":"E. Arak, T. Kailas, M. Müürisepp, A. Orav, A. Raal","doi":"10.3176/chem.2007.2.02","DOIUrl":"https://doi.org/10.3176/chem.2007.2.02","url":null,"abstract":"The volatile constituents from roots of Valeriana officinalis L. were investigated using GC and GC/MS methods. Valerianae radix samples were obtained from retail pharmacies or cultivated in Estonia. The roots of five V. officinalis samples yielded 0.28-1.16% essential oil in the cut drug, which usually corresponded (four samples) to the European Pharmacopeia standard (0.3%). The basic oil components among the identified 84 compounds were isovaleric acid (0-2.1%), -pinene (0.4-3.6%), -fenchene (0.6-5.8%), camphene (0.6-5.9%), bornyl acetate (8.8-33.7%), myrtenyl acetate (2.0-7.2%), alloaromadendrene (0.3-7.6%), myrtenyl isovalerate (1.1-2.5%), spathulenol (0.7-4.1%), sesquiterpen e alcohol (0.8-6.6%), valerianol (0.3-16.7%), valeranone (0.5-9.4%), and valerenal (tr-14.7%). Valerian root oil from Estonia (four samples) was rich in bornyl acetate and valerenal. Bornyl acetate, valerianol, and valera none dominated in one Estonian sample.","PeriodicalId":20551,"journal":{"name":"Proceedings of the Estonian Academy of Sciences. Chemistry","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89531411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Properties of CuInS2 free surface and the effect of conductive polymer layers on these properties","authors":"A. Verbitsky, Y. Vertsimakha, P. Lutsyk, S. Studzinsky, S. Bereznev, J. Kois, A. Öpik, Enn Mellikov","doi":"10.3176/chem.2006.2.08","DOIUrl":"https://doi.org/10.3176/chem.2006.2.08","url":null,"abstract":"The influence of thin conductive polymer layers on the surf ace photovoltage of CuInS2 (CIS) layers prepared using the so-called CISC uT method was studied. The deposition of poly(3,4- ethylenedioxythiophene) films on the free surf ace of CIS resulted in a small decrease in the height of the potential energetic barrier and in an increase in the efficiency of charge carriers transport through the CIS/polymer interface. The change of photovoltaic properties resulting from the polymer deposition on the free surface of CIS was also analysed for the carbazole polymers. Our results confirm the possibility of using the conductive polymer films as organic buffer layers in complete cell structures for photovoltaic cells based on the inorganic photoabsorber CIS.","PeriodicalId":20551,"journal":{"name":"Proceedings of the Estonian Academy of Sciences. Chemistry","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2006-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85115061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}