Papers by Keyword: Benzophenone

Abstract: Antigene technology is the one strategy for the artificial regulation of gene expression by the formation of triple structure on triplex forming oligonucleotide (TFO) with dsDNA. For the enhancement of the thermal stability of triplex structure, photo-crosslinking reaction is attractive by the covalent bond formation between TFO and dsDNA. In this paper, we designed the novel TFOs containing benzophenone moiety as a photo-crosslinkable agent. Several types of glycol nucleoside analogs having glycol scaffold and benzophenone residues with different linker length were prepared, and the these were incorporated into TFOs. The thermal stability of triplex and the photo-crosslinking reaction efficiency of TFOs toward dsDNA was systematically evaluated.

Abstract: A new simple, universal and highly-efficient method of substituted semicarbazone, thiosemicarbazone and aminoguanidine synthesis in the presence of I₂ was developed. The method was used to obtain a range of products with the structures confirmed by ¹H NMR Spectra.

Abstract: A castor oil-based UV-oligomer bearing benzophenone side chains (LU-5)was synthesis through two-step partial esterification reaction of polyacrylic acid with 4-hydroxy benzophenone and castor oil in the presence of N, N-diisopropyl carbodiimide and 4-(dimethylamino) pyridinium 4-toluenesulfonate(DPTS), then LU-5 was cured by UV irradiation with trimethylolpropane triacrylate(TMPTA) without any photoinitiator. The structure of the productions of the esterification reaction was characterized by Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance(NMR) and ultraviolet and visible spectrophotometer (UV-Vis), and the properties of UV cured polymer(FUV) has been studied. The results show that LU-5 has a certain light initiator activity, and it can be used as a macromolecular photoinitiator, the film of polymer has a certain degree of crosslinking.

Abstract: Solid-state photocycloaddition reactions between tri-2-pyrones (1a,1b) with benzophenone (2) gave the corresponding oxetane derivatives (3a:3a′=1:1 and 3b:3b′=1:1, 1:2 adducts) with high site- and regioselectivity across the C5-C6 , C5′-C6′ and C5′′-C6′′ double bonds in 1 via the triplet excited state of 2. The site- and regioselectivities were explained by MO calculations. The hydrogen-bonding interaction between 2 and 1a, 1b and the triplet reaction mechanism were also explained by the IR analyses and the quenching experiments, respectively.

Abstract: Solid-state photocycloaddition reactions between di-2-pyrones (1a-d) with benzophenone (2a) gave the corresponding oxetane derivatives (3a-d; 1:2 adducts) with high site- and regioselectivity across the C5-C6 and C5′-C6′ double bonds in 1 via the triplet excited state of 2a. The reactions were inferred by MO methods to be initiated by electrostatic interaction between the C6 position of 1a-d and the carbonyl oxygen of 2a at their ground states, and the solid-state interaction may be enhanced by electron density at carbonyl oxygen of the triplet 2a. The transition state (TS) analysis of the [2+2] cycloaddition reactions also suggested some triplet complex, and the high regioselectivity. The hydrogen-bonding interaction between 2a and 1a-d and the triplet reaction mechanism were also explained by the IR analyses and the quenching experiments, respectively.

Abstract: 2-hydroxy-4-glycidyl ether benzophenone(HGEBP) is synthesized with 2,4-dihydoxy- benzophenone(UV-0) and epichlorohydrin(ECH) as starting material, then a series of chitosan (CS) based novel ultraviolet absorbers (CS-g-UV-0) are synthesized by the reaction of chitosan with HGEBP in isopropylcarbinol in the presence of sodium hydroxide. The products(CS-g-UV-0) are characterized by means of Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD), and UV spectrophotometer. The results of UV absorption show that anyone of the grafted products has a strong ultraviolet absorption area ranging from 280nm to 350nm and the maximum absorption peak presents at 291 nm. It is found that the grafted products could improve the moisture-absorption and moisture-retention property with the increase of G% values.