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11.
Elisabeth Tillberg 《Plant Growth Regulation》1992,11(2):147-152
Dormancy-breaking treatment of the photosensitive Scots pine (Pinus sylvestris L.) seed by white light incubation or a 15-min exposure to red light decreased the abscisic acid content prior to radicle protrusion. Incubation in the dark or exposure to red light followed by a 5-min far-red light irradiation did not cause as great a decrease in abscisic acid content nor was the dormancy relieved. The ability of the far-red light to keep the ABA level high and to prevent germination gradually disappeared as the length of the dark period between the red and far-red treatments was increased to 24 h. ABA was quantified on a gas chromatograph with an electron capture detector. 相似文献
12.
《Bioorganic & medicinal chemistry letters》2020,30(17):127397
Herein, a boronic acid-based sensor was reported selectively to recognize Pd2+ ion. The fluorescence intensity increased 36-fold after sensor binding with 2.47 × 10−5 M of Pd2+ ion. It was carried out in the 99% aqueous solution for binding tests, indicating sensor having good water solubility. In addition, it is discernible that Pd2+ ion turned on the blue fluorescence of sensor under a UV–lamp (365 nm), while other ions (Ag+, Al3+, Ba2+, Ca2+, Cr2+, Cd2+, Co2+, Cs2+, Cu2+, Fe2+, Fe3+, K+, Li+, Mg2+, Mn2+, Na+, Ni2+ and Zn2+) did not show the similar change. Furthermore, sensor has a low limit of detection (38 nM) and high selectivity, which exhibits the potential for the development of Pd2+ recognition in practical environments. 相似文献
13.
《Bioorganic & medicinal chemistry letters》2020,30(16):127289
The present research project details synthesis of new hybrid methanofullerenes based on acetylene and triazole esters of malonic acid containing 5Z,9Z-dienoic acids and fullerene C60 under Bingel-Hirsch conditions, including study of the cytotoxic activity with respect to Jurkat, K562, U937 and HL60 tumor cell lines. Hybrid methanofullerenes containing acetylenic fragments, unlike triazole substituents, were found to exhibit higher cytotoxicity, but are characterized by lower selectivity of action in relation to healthy cells. 相似文献
14.
《Bioorganic & medicinal chemistry letters》2020,30(10):127107
The steady rise of the antimicrobial resistance is a major global threat to human health that requires the urgent need for novel antibiotics. In this work we report the synthesis of a small library of 3-subsituted-5-arylidene tetramic acids in order to investigate the scope of our previously established methodology via an intermediate oxazolone and their antimicrobial activity. From this series of 14 tetramic acids, 11 derivatives are novel and one of them is a Schiff base, which was structurally characterized with single-crystal X-ray analysis and NMR spectroscopy. The compounds incorporating a lipophilic acyl group at carbon-3 of the ring showed moderate to high activity with minimum inhibitory activity of 4–32 μg/mL against methicillin-resistant Staphylococcus aureus (MRSA), accompanied by no human cell toxicity and hemolytic activity within the tested concentration range. The substituent at para position of the aryl ring seemed to have no or little effect on the antimicrobial activity of these compounds. 相似文献
15.
Laura Santagostini Elisabetta Caporali Claudia Giuliani Martina Bottoni Roberta Ascrizzi Silvia R. Araneo 《Plant biosystems》2020,154(3):316-325
AbstractSeveral aroma hops (Humulus lupulus L.) were recently introduced in Northern Italy as a small-scale production of excellence. In this preliminary study, the American cultivar Cascade was investigated in a combined morphological and phytochemical survey. Morphological investigation on trichome structure, density and distribution was performed by scanning electron microscopy and light microscopy. Essential oil composition, α/β-acid and polyphenol profiles over 3 years were determined by GC-MS and HPLC analyses. Two types of non-glandular (simple and cystolithic) and glandular (peltate and bulbous) trichomes were observed on leaves and female inflorescences. The peltate trichomes resulted as the main sites of terpene production and accumulation. The essential oil profiles showed myrcene, β-caryophyllene, (E)-β-farnesene and humulene epoxide II as the dominant compounds over the three collection times, although with different relative abundances. The presence of two exclusive compounds, γ-muurolene and trans-γ-cadinene, characterized the investigated cv. Cascade, potentially enhancing herbal, woody and spicy aroma traits of this cultivation in Northern Italy. The bitter acid composition showed quantitative values consistent with literature data only for the second and third monitoring year. Qualitative differences in polyphenol content were also recorded, for the presence of quercetin-3-O-malonylglucoside and kaempferol-3-O-rutinoside, which may characterize this peculiar Italian cultivation. 相似文献
16.
17.
Andrea Dichlberger Stefanie Schlager Katariina Maaninka Wolfgang J. Schneider Petri T. Kovanen 《Journal of lipid research》2014,55(12):2471-2478
Human mast cells (MCs) contain TG-rich cytoplasmic lipid droplets (LDs) with high arachidonic acid (AA) content. Here, we investigated the functional role of adipose TG lipase (ATGL) in TG hydrolysis and the ensuing release of AA as substrate for eicosanoid generation by activated human primary MCs in culture. Silencing of ATGL in MCs by siRNAs induced the accumulation of neutral lipids in LDs. IgE-dependent activation of MCs triggered the secretion of the two major eicosanoids, prostaglandin D2 (PGD2) and leukotriene C4 (LTC4). The immediate release of PGD2 from the activated MCs was solely dependent on cyclooxygenase (COX) 1, while during the delayed phase of lipid mediator production, the inducible COX-2 also contributed to its release. Importantly, when ATGL-silenced MCs were activated, the secretion of both PGD2 and LTC4 was significantly reduced. Interestingly, the inhibitory effect on the release of LTC4 was even more pronounced in ATGL-silenced MCs than in cytosolic phospholipase A2-silenced MCs. These data show that ATGL hydrolyzes AA-containing TGs present in human MC LDs and define ATGL as a novel regulator of the substrate availability of AA for eicosanoid generation upon MC activation. 相似文献
18.
Hyun-Jin Kang Tuong Vy Thi Le Kyungmin Kim Jeonghwan Hur Kyeong Kyu Kim Hyun-Ju Park 《Journal of molecular biology》2014
Both G-quadruplex and Z-DNA can be formed in G-rich and repetitive sequences on genome, and their formation and biological functions are controlled by specific proteins. Z-DNA binding proteins, such as human ADAR1, have a highly conserved Z-DNA binding domain having selective affinity to Z-DNA. Here, our study identifies the Z-DNA binding domain of human ADAR1 (hZαADAR1) as a novel G-quadruplex binding protein that recognizes c-myc promoter G-quadruplex formed in NHEIII1 region and represses the gene expression. An electrophoretic migration shift assay shows the binding of hZαADAR1 to the intramolecular c-myc promoter G-quadruplex-forming DNA oligomer. To corroborate the binding of hZαADAR1 to the G-quadruplex, we conducted CD and NMR chemical shift perturbation analyses. CD results indicate that hZαADAR1 stabilizes the parallel-stranded conformation of the c-myc G-quadruplex. The NMR chemical shift perturbation data reveal that the G-quadruplex binding region in hZαADAR1 was almost identical with the Z-DNA binding region. Finally, promoter assay and Western blot analysis show that hZαADAR1 suppresses the c-myc expression promoted by NHEIII1 region containing the G-quadruplex-forming sequence. This finding suggests a novel function of Z-DNA binding protein as a regulator of G-quadruplex-mediated gene expression. 相似文献
19.
James E. Swain Richard Robitaille Gavin R. Dass Milton P. Charlton 《Developmental neurobiology》1991,22(8):855-864
We examined the role of phosphatases in synaptic transmission using the permeant phosphatase inhibitor okadaic acid (OA). In the crayfish neuromuscular junction (NMJ), postsynaptic effects including increases in input resistance occurred at doses greater than 5 μM OA. At lower doses (0.5–5 μM) the effects were solely presynaptic and transmitter release increased over three-fold despite small reductions in amplitude and duration of presynaptic action potentials. Potentiating effects of serotonin on transmitter release, Which depend on phosphorylation, were increased by OA. Frequency facilitation was reduced but its decay was not affected. In frog NMJs, OA increased spontaneous and evoked release two-fold through presynaptic mechanisms. An inactive analog of OA, OA tetra-acetate, had no effect on transmitter release at frog and crayfish NMJ. Therefore, phosphatases have a strong modulating influence on synaptic transmission. 相似文献
20.
J. Orpiszewski C. Hebda J. Szykua R. Powls S. Clasper H.H. Rees 《FEMS microbiology letters》1991,82(2):233-236
Six out of seven tested strains of mycobacteria transformed abietic acid to methyl abietate in shake culture. The conversion carried out by Mycobacterium sp. MB 3683 was induced by the substrate and stimulated by methionine. Fractionation of the cell extract of Mycobacterium sp. MB 3683 on DEAE cellulose, Ultrogel AcA 44 and MONO Q resulted in the separation of three distinct methyltransferase activities which could also esterify palmitic acid. The separated forms of the methyltransferase exhibited different activities towards these two substrates. 相似文献