Unraveling the Molecular Weight Dependence of High Magnetic Field to Manipulate the Semiconducting Polymer Molecular Orientation.

The magnetic alignment of molecules, which exploits the anisotropy of diamagnetic susceptibility, provides a clean and versatile approach to the structural manipulation of semiconducting polymers. Here, the magnetic-alignment dynamics of two molecular-weight (MW) batches of a diketopyrrolopyrrole (DPP)-based copolymer (PDVT-8) were investigated. Microstructural characterizations revealed that the magnetically aligned, high-MW (Mn = 53.7 kDa) PDVT-8 film exhibited a higher degree of backbone chain alignment and film crystallinity compared with the low-MW (Mn = 17.6 kDa) PDVT-8 film grown via the same magnetic alignment method. We found that as the MW increases, the degree of preaggregation of the polymer molecules in solution significantly increases and the aggregation mode changes from H-aggregation to J-aggregation through a cooperative assembly mechanism. These events improved the responsiveness of high-MW polymer molecules to magnetic fields. Field-effect transistors based on the magnetic aligned high-MW PDVT-8 films exhibited a 6.8-fold increase in hole mobility compared to the spin-coated films, along with a mobility anisotropy ratio of 12.6. This work establishes a significant correlation among chain aggregation behavior in solution, polymer film microstructures, magnetic responsiveness, and carrier transport performance in donor-acceptor polymer systems.

Preparation and properties of octenyl succinate ß-cyclodextrin and its application as an emulsion stabilizer.

The aim of this study was to synthesize and characterize the octenyl succinic-ß-cyclodextrin (OS-ß-CD) and assess its application as a potential emulsion stabilizer. OS-ß-CD was prepared by esterifying ß-CD with OSA under alkaline conditions. The properties of OS-ß-CD were characterized by Fourier transform infrared, 13C and 1H NMR spectroscopy, X-ray diffraction (XRD), which demonstrated that OS groups had been introduced into the ß-CD molecules and most of OS substitution occurred at the C-6 hydroxyl group of glycosyl units. The properties of emulsions stabilized by ß-CD and OS-ß-CD were evaluated via surface and interface tensiometry, determination of the creaming index and droplet size. The results showed that emulsions stabilized by ß-CD broke just after 24h storage at 25°C. The emulsions prepared by OS-ß-CD with all degree of substitution (DS) possessed a smaller oil droplet size and improved storage stability compared with that of the emulsion generated using ß-CD.

Discovery and SARs of trans-3-aryl acrylic acids and their analogs as novel anti-tobacco mosaic virus (TMV) agents.

A series of trans-3-aryl acrylic acids 1-27 and their derivatives 28-34 were prepared and evaluated for their antiviral activity against tobacco mosaic virus (TMV) for the first time. The bioassay results showed that most of these compounds exhibited good antiviral activity against TMV, of which compounds 1, 5, 6, 20, 27 and 34 exhibited significantly higher activity against TMV than commercial Ribavirin both in vitro and in vivo. Furthermore, these compounds have more simple structure than commercial Ribavirin, and can be synthesized more efficiently. These new findings demonstrate that trans-3-aryl acrylic acids and their derivatives represent a new template for antiviral studies and could be considered for novel therapy against plant virus infection.

A novel tylophorine analog NK-007 ameliorates colitis through inhibition of innate immune response.

In this study, we synthesized (±)-tylophorine malate (NK-007), an analog of tylophorine (DCB3503), and analyzed its anti-inflammatory effect in vivo using a dextran sulfate sodium (DSS)-induced colitis model and an acetic acid-induced colitis model. As indicated by disease activity index (DAI) and degree of macroscopic colonic damage, NK-007 can significantly suppress colitis. To delineate the underlying mechanism, we have explored the influence of NK-007 on the production of TNF-α by murine primary bone marrow-derived dendritic cells (BMDCs) as well as monocyte/macrophage cell line Raw 264.7 triggered by lipopolysaccharide (LPS). For both types of innate immune cells, NK-007 showed a potent TNF-α inhibitory effect, and has in addition reduced the expression of IL-12 in BMDCs. Moreover, Raw cells treated with NK-007 also showed decreased phosphorylation of NF-κB, which may explain the protective immune-regulatory effect of NK-007 for experimental colitis.

Design, synthesis, and antiviral evaluation of phenanthrene-based tylophorine derivatives as potential antiviral agents.

A series of C9-substituted phenanthrene-based tylophorine derivatives (PBTs) were designed, synthesized, and first evaluated for their antiviral activities against tobacco mosaic virus (TMV). These compounds contain a phenanthrene core structure and can be synthesized some efficiently with excellent yields compared with tylophorine alkaloid. The bioassay results show that some of these compounds exhibited higher antiviral activity against TMV in vivo than tylophorine and commercial Ningnanmycin. Especially, compounds 3, 4, 9, 13, and 16 emerged as potential inhibitors of plant virus. These new findings demonstrate that these phenanthrene-based tylophorine derivatives (PBTs) represent another new template for antiviral studies and could be considered for novel therapy against plant virus infection.

Synthesis and antiviral activities of phenanthroindolizidine alkaloids and their derivatives.

Racemic phenanthroindolizidine alkaloids tylophorine, antofine, and deoxytylophorinine, and optically pure alkaloids S-(+)-tylophorine and R-(-)-tylophorine were synthesized and evaluated for their antiviral activities against tobacco mosaic virus (TMV). Further salinization modifications based on tylophorine increased stability and water solubility and improved the antiviral activity in application. The bioassay results showed that most of these synthesized compounds showed higher antiviral activity against TMV in vitro and in vivo than commercial Ningnanmycin. Especially, tylophorine salt derivatives 10, 11, 13, 17, and 22 emerged as potential inhibitors of plant virus. These findings demonstrate that these phenanthroindolizidine alkaloids and their salt derivatives represent a new template for antiviral studies and could be considered for novel therapy against plant virus infection.