Synthesis of esters derived from 2,3,4-tri-O-benzyl-alpha-D-methylglucoside

The synthesis of a set of esters obtained from the D-glucose derivative by reaction with several carboxylic acids: benzoic, phenylacetic, acetylsalicylic, 2-(3-bromopropoxy)benzoic acid and 4-(toluene-4- sulfonylamino)benzoic acid.FCT (Fundação para a Ciência e Tecnologia) and FEDER for financial support. The Bruker Avance III 400 spectrometer is part of the National NMR network and was purchased under the framework of the National Programme for Scientific Reequipment, contract REDE/1517/RMN/2005, with funds from POCI 2010 (FEDER) and (FCT). We are also grateful for research grant VZ MSMT- 0021627501, Czech Republic

Synthesis of esters derived from [4-(2-hydroxyethyl)-[1,2,3]triazol-1-yl]-2,3,4,6-tetra-O-acetyl-β-D-glucopyranose

The synthesis of six novel esters containing a triazole ring and an acetylated glucose residue are presentedFCT and FEDER, for National NMR Network (Bruker Avance II 400). We are also grateful for research grant VZ MSMT-0021627501, Czech Republi

Synthesis of esters derived from [4-(2-hydroxy-ethyl)-[1,2,3]triazol-1-YL-2,3,4,6-tetra-o-acetylglucopyranose

2,3,4-Tri-O-benzyl-alpha-D-methylglucoside was prepared and reacted with several acids: benzoic, phenylacetic, 2-(3-bromo-propoxy)-benzoic, acetylsalicylic and 4-(toluene-4-sulfonylamino)-benzoic. The products were isolated with low to fair yields and fully characterized by usual analytical techniquesFundação para a Ciência e Tecnologia and FEDER, for National NMR Network (Bruker Avance III 400). We are also grateful for research grant VZ MSMT-0021627501, Czech Republic

Naphthotriazole derivatives : synthesis and fluorescence properties

Eight fluorescent compounds containing a naphthotriazole moiety substituted at position 2 by a (vinylsulfonyl)aryl group or its precursors, containing hydroxyl or sulphonic groups or N-methylglycine, were prepared and characterized. The products were recovered in moderate yields after column chromatography or recrystallization and identified by proton and carbon nuclear magnetic resonance spectroscopy. Double resonance, heteronuclear multiple quantum coherence and heteronuclear multiple bond correlation experiments were carried out for complete assignment of proton and carbon signals. Absorption and emission spectra were obtained, in acetonitrile, for all the compounds and the fluorescence quantum yields determined. All compounds are promising fluorescent probes due to their high fluorescence quantum yields.Research grant VZ MSMT-0021627501, Czech RepublicFundação para a Ciência e a Tecnologia (FCT) - REEQ/ 630/QUI/2005; REDE/1517/RMN/2005FEDER - REEQ/ 630/QUI/2005; REDE/1517/RMN/200

Caspase-dependent and -independent suppression of apoptosis by monoHER in Doxorubicin treated cells

Doxorubicin (DOX) is an antitumour agent for different types of cancer, but the dose-related cardiotoxicity limits its clinical use. To prevent this side effect we have developed the flavonoid monohydroxyethylrutoside (monoHER), a promising protective agent, which did not interfere with the antitumour activity of DOX. To obtain more insight in the mechanism underlying the selective protective effects of monoHER, we investigated whether monoHER (1 mM) affects DOX-induced apoptosis in neonatal rat cardiac myocytes (NeRCaMs), human endothelial cells (HUVECs) and the ovarian cancer cell lines A2780 and OVCAR-3. DOX-induced cell death was effectively reduced by monoHER in heart, endothelial and A2780 cells. OVCAR-3 cells were highly resistant to DOX-induced apoptosis. Experiments with the caspase-inhibitor zVAD-fmk showed that DOX-induced apoptosis was caspase-dependent in HUVECs and A2780 cells, whereas caspase-independent mechanisms seem to be important in NeRCaMs. MonoHER suppressed DOX-dependent activation of the mitochondrial apoptotic pathway in normal and A2780 cells as illustrated by p53 accumulation and activation of caspase-9 and -3 cleavage. Thus, monoHER acts by suppressing the activation of molecular mechanisms that mediate either caspase-dependent or -independent cell death. In light of the current work and our previous studies, the use of clinically achievable concentrations of monoHER has no influence on the antitumour activity of DOX whereas higher concentrations as used in the present study could influence the antitumour activity of DOX

Genomic comparisons reveal biogeographic and anthropogenic impacts in the koala (Phascolarctos cinereus): a dietary-specialist species distributed across heterogeneous environments

The Australian koala is an iconic marsupial with highly specific dietary requirements distributed across heterogeneous environments, over a large geographic range. The distribution and genetic structure of koala populations has been heavily influenced by human actions, specifically habitat modification, hunting and translocation of koalas. There is currently limited information on population diversity and gene flow at a species-wide scale, or with consideration to the potential impacts of local adaptation. Using species-wide sampling across heterogeneous environments, and high-density genome-wide markers (SNPs and PAVs), we show that most koala populations display levels of diversity comparable to other outbred species, except for those populations impacted by population reductions. Genetic clustering analysis and phylogenetic reconstruction reveals a lack of support for current taxonomic classification of three koala subspecies, with only a single evolutionary significant unit supported. Furthermore, similar to 70% of genetic variance is accounted for at the individual level. The Sydney Basin region is highlighted as a unique reservoir of genetic diversity, having higher diversity levels (i.e., Blue Mountains region; AvHe(corr)-0.20, PL% = 68.6). Broad-scale population differentiation is primarily driven by an isolation by distance genetic structure model (49% of genetic variance), with clinal local adaptation corresponding to habitat bioregions. Signatures of selection were detected between bioregions, with no single region returning evidence of strong selection. The results of this study show that although the koala is widely considered to be a dietary-specialist species, this apparent specialisation has not limited the koala's ability to maintain gene flow and adapt across divergent environments as long as the required food source is available