Trihydroxybenzoic Acid Dimer-induced Apoptosis Effects in vitro

The in vitro inhibitory effect of trihydroxybenzoic acid dimer(TAD) extracted from Trapabispinosd roxb on HeLa cell growth was investigated via the MTT[3-(4,5-dimethylthiazol-2-yl)-2,5-diophenyl-tetrazolium bromide] reduction method. The morphological changes of HeLa cells were observed by means of an optical microscope and a transmission electron microscope(TEM); the cell circles and apoptosis were detected by a flow cytometer. It was found that TAD can significantly inhibit the growth of Hela cells and can induce the apoptosis of HeLa cells. It was also found that the inhibition to the growth of Hela cells and the induction to the apoptosis of HeLa cells have a dosage-dependent feature. The inhibiting rates of TAD with mass concentrations of 25.000, 12.500 and 6.250 mg/L to the HeLa cell growth were 52.04%, 34.44% and 23.72% after 30 h, respectively, while those with TAD mass concentrations of 100.000, 50.000, 25.000, 12.500, 6.250 and 3.125 mg/L showed positive correlation with a correlation coefficient value of r=0.9859(P<0.01) and a IC_ 50 value of 10.90 mg/L. Observed by means of TEM, the HeLa cells exposed to 25.000, 12.500 and 6.250 mg/L TAD showed apoptosis to various extents, shrinkage of the cell nuclei, condensation and margination of chromatin, and cavitation of mitochondrion. An apoptosis peak was detected via a flow cytometer. It can be drawn from the results that TAD extracted from Trapabispinosd roxb has an evident inhibitory effect on the proliferation of and an inductive effect on the apoptosis of HeLa cells, but has no obvious arrest action towards the cell circles of HeLa cells.

SALVIANOLIC ACID G,A CAFFEIC ACID DIMER WITH A NOVEL TETRACYCLIC SKELETON

Salvianolic acid G,a caffeic acid dimer with a novel tetracyclic skeleton was isolated from the roots of Salvia miltiorrhiza.Its structure was elucidated by chemical and spectral analysis,especially by 2D NMR analysis.

Synthesis and Characterization of Polyamides Based on Dimer Acid

A series of dimer acid-based polyamides were synthesized by melt-polycondensation of dimer acid and various aromatic diamines, and were characterized by Fourier transform infrared spectrum （FT-IR） and nuclear magnetic resonance （^1H NMR）. The physical properties of the polyamides, such as glass transition temperature, melting temperature, decomposition temperature and mechanical properties were also investigated. The polyamides＇ intrinsic viscosity ranges from 1.8 dL·g^-1 to 2.2 dL·g^-1, and the melting temperature ranges from 140 ℃ to 181 ℃. The glass transition temperatures, observed from dynamic mechanical analysis, fall in the range of 34.8-48.2 ℃. The physical and mechanical properties of the resultant polyamides are similar to those of the PA1212. The heat resistance and mechanical properties of poly （4, 4′-diphenylsulfone dimeramide） （PSD） and poly（4, 4′-di pb enyl dimeramide） （PPDI） are comparable to those of PA 1212.

Curing Behaviors and Thermal Properties of Dimer Fatty Acid （DFA） Modified Multifunctional Epoxy Resin

In order to improve the toughness of the cured aromatic tetrafunctional epoxy resins, a dlmer rarboxylic acid named dlmer fatty acid （DFA） was used to modify an aromatic tetrafunctional epoxy, N, N, N＇, N＇-tetraglycidyl-2,2-bis [ 4-（ 4-aminophcuoxy ） phenyl ] propane （TGBAPP）. The curing behaviors of DFA- TGBAPP/MNA （ methyl nadic anhydride） systems were studied by differential scanning calorimetry （DSC） method. And the thermal properties of the cured epoxy resin were investigated with the thermo-gravimetric analysis （TGA） and dynamic mechanical analysis （DMA）. Besides, the toughness was characterized with the impact strength tested by charpy impact testing. The results indicated that the modification would improve the curing reactions, and the curing temperatures were decreased with the increasing content of DFA. The thermal properties were not influenced obviously, and the toughness could be improved when the epoxy resin was modified with DFA.

Preparation and Properties of Vegetable-Oil-Based Thioether Polyol and Ethyl Cellulose Supramolecular Composite Films

Ethyl cellulose(EC),an important biomass-based material,has excellent film-forming properties.Nevertheless,the high interchain hydrogen bond interaction leads to a high glass transition temperature of EC,which makes it too brittle to be used widely.The hydroxyl group on EC can form a supramolecular system in the form of a non-covalent bond with an effective plasticizer.In this study,an important vegetable-oil-based derivative named dimer fatty acid was used to prepare a novel special plasticizer for EC.Dimer-fatty-acid-based thioether polyol(DATP)was synthesized and used to modify ethyl cellulose films.The supramolecular composite films of DATP and ethyl cellulose were designed using the newly-formed van der Waals force.The thermal stability,morphology,hydrophilicity,and mechanical properties of the composite films were all tested.Pure EC is fragile,and the addition of DATP makes the ethyl cellulose films more flexible.The elongation at the break of EC supramolecular films increased and the tensile strength decreased with the increasing DATP content.The elongation at the break of EC/DATP(60/40)and EC/DATP(50/50)was up to 40.3%and 43.4%,respectively.Noticeably,the thermal initial degradation temperature of the film with 10%DATP is higher than that of pure EC,which may be attributed to the formation of a better supramolecular system in this composite film.The application of bio-based material(EC)is environmentally friendly,and the novel DATP can be used as a special and effective plasticizer to prepare flexible EC films,making it more widely used in energy,chemical industry,materials,agriculture,medicine,and other fields.

Thermal,physical and mechanical properties of hydrogenated dimer acid-based Nylon 636/Nylon 66 copolymers

Hydrogenated dimer acid-based Nylon 636/Nylon 66 copolymers were synthesized by in situ polymerization. The effects of Nylon 66 contents on the copolymers were characterized by intrinsic viscosity measurements, attenuated total reflection-Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis and mechanical tests. The results showed that incorporation of Nylon 66 into hydrogenated dimer acid-based Nylon had no significant effect on the glass transition or melting temperatures. However, the crystallization temperature, crystallinity degree and the maximum rate of decomposition temperature from derivative thermogravimetry measurements vary. Mechanical testing data revealed that with increasing Nylon 66 concentrations, the tensile strength of copolymers increased, while the elongation at break point and notched izod impact strength decreased. The physical and mechanical properties of HN-40, HN-50 and HN-60 are similar to those of the current PAl 1, PAl212, and PAlll 1 Nylon products.

Highly Efficient White-Light Emission Induced by Carboxylic Acid Dimers in a Layered Hybrid Perovskite

Broadband white-light emission in metal halides has been intensely explored because of their facile solution processability,structural adjustability,and high color rendering index.However,the most reported quantum yields for white-light emission remain low despite great efforts.Herein,we report a metal-halide layered perovskite,(HOOC_(4)H_(9)NH_(3))_(2)PbBr_(4),showing the typical white-light emission with a highly enhan ced quantumyield up to 21.2% compared to previously reported noncarboxyl layered hybrid perovskites(0.5-9%).Notably,mechanistic studies reveal that the distinctive carboxylic acid dimers largely increase the structure rigidity and in consequence reduce the nonradiative recombination induced by stretching vibration.To the best of our knowledge,this strategy is important in hybrid perovskites,which is effective and propagable to acquire prominent photoluminescence.This work will shed light on the design of highly emissive white-light materials involving intense intermolecular interaction and promote their potential in displaying application.