8 research outputs found

    Superphanes: Facile and Efficient Preparation, Functionalization and Unique Properties

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    Superphanes, compounds in which the two benzene rings clamped parallel on top of each other by six bridges, have garnered considerable interest due to their aesthetically pleasing structures and unique chemical physical properties. However, until now progress in the research of superphane chemistry and beyond has been seriously hampered by their poor availability. Herein, we report the facile and scalable synthesis of a collection of superphanes with structural diversity and their unique photophysical properties, as well as their unusual host–guest behavior. Initially, a set of dodecaimino–containing super-phanes 7a–7e are obtained via dynamic self–assembly of a hexakis–amine and a series of readily derived aromatic dialde-hyde in one pot. The resulting superphanes are found capable of being reduced with NaBH4 to their corresponding second-ary–amine versions 3a–3e. Subsequently, superphane 3c bearing 12 amine–NHs was further subject to post–functionalization with various functional groups, e.g., ethyl, allyl, propargyl and but–2–yn–1–yl. Unprecedentedly, the sec-ondary amine–based superphanes 3a–3e were observed to exhibit genuine fluorescence both in solution and in the solid state while the imine–based superphanes 7a–7e were found to highly emissive only in solid state with fluorescent quantum yields of 3.5 ~ 17.1. Finally, fully protonated 3a was exemplified to encapsulate a 2Cl–·H2O cluster both in the solid state and in solution. With the easy and versatile synthesis, modification, as well as unique photophysical and host–guest properties, we believe that this study will break the bottleneck in superphane chemistry and open the door to a novel class of supramo-lecular hosts and advanced functional materials on the basis of superphanes

    Superphanes: Old Yet New Binding–Agents for Highly Selective Recognition of Fluoride by Size–Sieving Effect

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    Superphanes, namely percyclophanes, have been widely investigated for the sake of their aesthetically pleasing structures with high symmetry, intriguing physical and chemical properties and synthetic challenges. Nonetheless, the host–guest chemistry of superphanes remains to be an unmet challenge. Herein, we delineate the design, preparation, characterization, and host–guest chemistry of an unprecedented superphane 15, which was evidenced by mass spectroscopy, NMR spectroscopy, X–ray crystallography, and DFT calculations. 15 features six bridges between two benzene planes, up to 18 Csp–H hydrogen–bonding donors well–distributed around the near–closed inner cavity in three dimensions. These allow 15 to exhibit exclusive selectivity towards F– against Cl–, Br–, I–, N3–, SCN–, NO3–, ClO4–, SO42– and HP2O73– due to the size–sieving effect. This contribution opens up new opportunities for design and synthesis of new supramolecular hosts for anions of interest with high selectivity.</p

    Genome Survey Sequencing of Dioscorea zingiberensis

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    Dioscorea zingiberensis (Dioscoreceae) is the main plant source of diosgenin (steroidal sapogenins), the precursor for the production of steroid hormones in the pharmaceutical industry. Despite its large economic value, genomic information of this Dioscorea genus is currently unavailable. Here, we present an initial survey of the D. zingiberensis genome performed by next-generation sequencing technology together with a genome size investigation inferred by flow cytometry. The whole genome survey of D. zingiberensis generated 31.48 Gb of sequence data with approximately 78.70Ä‚ coverage. The estimated genome size is 800 Mb, with a high level of heterozygosity based on K-mer analysis. These reads were assembled into 334,288 contigs with a N50 length of 1,079 bp, which were further assembled into 92,163 scaffolds with a total length of 173.46 Mb. A total of 4935 genes, 81 tRNAs, 69 rRNAs, and 661 miRNAs were predicted by the genome analysis, and 263,484 repeated sequences were obtains with 419,372 simple sequence repeats (SSRs). Among these SSRs, the mononucleotide repeat type was the most abundant (up to 54.60% of the total SSRs), followed by the dinucleotide (29.60%), trinucleotide (11.37%), tetranucleotide (3.53%), pentanucleotide (0.65%), and hexanucleotide (0.25%) nucleotide repeat types.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

    Molecular Characterization and Overexpression of <i>SmJMT</i> Increases the Production of Phenolic Acids in <i>Salvia miltiorrhiza</i>

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    Jasmonic acid (JA) carboxyl methyltransferase (JMT), a key enzyme in jasmonate-regulated plant responses, may be involved in plant defense and development by methylating JA to MeJA, thus influencing the concentrations of MeJA in plant. In this study, we isolated the JMT gene from Salvia miltiorrhiza, an important medicinal plant widely used to treat cardiovascular disease. We present a genetic manipulation strategy to enhance the production of phenolic acids by overexpresion SmJMT in S. miltiorrhiza. Global transcriptomic analysis using RNA sequencing showed that the expression levels of genes involved in the biosynthesis pathway of phenolic acids and MeJA were upregulated in the overexpression lines. In addition, the levels of endogenous MeJA, and the accumulation of rosmarinic acid (RA) and salvianolic acid (Sal B), as well as the concentrations of total phenolics and total flavonoids in transgenic lines, were significantly elevated compared with the untransformed control. Our results demonstrate that overexpression of SmJMT promotes the production of phenolic acids through simultaneously activating genes encoding key enzymes involved in the biosynthesis pathway of phenolic acids and enhancing the endogenous MeJA levels in S. miltiorrhiza
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