Short and sweet: Glycosidation of 2‐deoxyglycosyl imidates with I2 as shown in the scheme (Bn=benzyl, Bz=benzoyl, MS=molecular sieves) proceeds smoothly to provide the corresponding β‐linked 2‐deoxyglycosides in excellent yields and selectivity. This coupling method has been shown to be adaptable to the synthesis of various β‐linked oligosaccharides containing 2,6‐dideoxy‐ and 2,3,6‐trideoxyglycosides.

We developed metal-insulator-semiconductor-type organic light-emitting transistors (MIS-OLETs), and improved their properties by optimizing the device structure. MIS-OLETs showed a maximum drain current ofand on/off ratio of over 10 4 . Moreover an active-matrix display using MIS-OLETs on a plastic substrate was fabricated. The developed 16 Â 16 active-matrix-drive organic light-emitting transistors (AMOLET) showed excellent properties by optimizing device structure.

The authors report the characteristics of novel metal-insulator-semiconductor-type organic light-emitting transistors (MIS-OLETs). The drain current and luminescent intensity of the MIS-OLET can be controlled by changing hole injection carriers by applying a gate bias voltage. In addition, the high performance (400cd∕m2 at VD=−8V) of MIS-OLETs fabricated on a plastic substrate as well as on a glass substrate is demonstrated and described.

In this report, we describe the stereoselective synthesis of a combinatorial library comprised of 16 deoxyhexasaccharides that are related to a landomycin A sugar moiety, based on an orthogonal deprotection strategy. The use of an olivosyl donor containing a benzyl ether at the C3 position and benzoyl ester at the C4 position, and the olivosyl donor, a naphthylmethyl ether, and a p-nitrobenzylethyl or benzyl sulfonyl ester enabled the synthesis of a set of four diolivosyl units containing a hydroxyl group at the C3 or C4 position by a simple glycosylation and deprotection procedure. Using a phenylthio 2,3,6-trideoxyglycoside, alpha-selective glycosidation proceeded without anomerization of the 2,6-dideoxy-beta-glycosides. In addition, alkylhydroquinone and levulinoyl groups were found to be an effective set of orthogonal protecting groups for the anomeric position and a hydroxyl group. The coupling of all combinations of trisaccharide units in a beta-selective manner was accomplished by activation of the glycosyl imidate with I(2) and Et(3)SiH. No cleavage of the acid-labile 2,3,6-trideoxyglycoside was observed under the conditions used for the reactions. Finally, all of the protected hexasaccharides were deprotected by hydrolysis of the esters, microwave (MW) assisted cleavage of the 2-trimethylsilylethoxymethoxy (SEM) ether, and a Birch reduction.

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Efficient synthesis of the deoxysugar part of versipelostatin (VST) was achieved by direct and stereoselective glycosylation of the reduced VST aglycon. Activation of 2-deoxyglycosyl imidate with IBr under basic conditions enables alpha-selective glycosylation of beta-2-deoxylglycosides without anomerization. Comparison of the synthetic and natural VST products using NMR indicates that versipelostatin has a beta-D-digitoxose-(1,4)-alpha-L-oleandrose-(1,4)-beta-D-digitoxose trisaccharide. In addition, results of a biological assay indicate that the deoxyoligosaccharide unit of the synthetic glycoside was important for biological activity of the compound.

Encapsulation of highly emissive alkynylpyrenes with permethylated α-cyclodextrin (PM-α-CD) followed by capping reaction yielded alkynylpyrene-based [3]rotaxanes. The [3]rotaxane emitted only blue light of monomeric pyrene under various circumstances such as lipophilic, hydrophilic, and even condensed states and exhibited extremely high stability for UV irradiation. These properties would result because PM-α-CD, like bulletproof glass, protected the alkynylpyrene core from the attack of another excited alkynylpyrene and singlet oxygen generated by the energy transfer from the excited alkynylpyrene.

BackgroundWe recently demonstrated the cytotoxicity of liquid crystal precursors (hereafter referred to as “mesogenic compounds”) in the human non-small cell lung cancer (NSCLC) cell line A549 which carry wild-type p53. p53 mutations are observed in 50 % of NSCLC and contribute to their resistance to chemotherapy. To develop more effective and cancer-specific agents, in this study, we investigated the structure–activity relationships of mesogenic compounds with cytotoxic effects against multiple NSCLC cells.MethodsThe pharmacological effects of mesogenic compounds were examined in human NSCLC cells (A549, LU99, EBC-1, and H1299) and normal WI-38 human fibroblast. Analyses of the cell cycle, cell-death induction, and capsases expression were performed.ResultsThe 3-ring compounds possessing terminal alkyl and hydroxyl groups (compounds C1–C5) showed cytotoxicity in NSCLC cells regardless of the p53 status. The compounds C1 and C3, which possess a pyrimidine at the center of the core, induced G2/M arrest, while the compounds without a pyrimidine (C2, C4, and C5) caused G1 arrest; all compounds produced caspase-mediated cell death. These events occurred in a p53-independent manner. Furthermore, it was suggested that compounds induced cell death through p53-independent DNA damage-signaling pathway. Compounds C2, C4, and C5 did not show strong cytotoxicity in WI-38 cells, whereas C1 and C3 did. However, the cytotoxicity of compound C1 against WI-38 cells was improved by modulating the terminal alkyl chain lengths of the compound.ConclusionsWe showed the p53-indepdent structure–activity relationships of mesogenic compounds related to the cytotoxic effects. These structure–activity relationships will be helpful in the development of more effective and cancer-specific agents.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-016-2585-6) contains supplementary material, which is available to authorized users.