桦木醇丁二酸酯氨基酸叔丁酯的合成及对肝癌细胞增殖和凋亡的影响

以桦木醇为原料合成了桦木醇丁二酸酯甘氨酸叔丁酯(桦甘酯)和桦木醇丁二酸酯丙氨酸叔丁酯(桦丙酯),采用1H NMR和MS确证了化合物的结构。用噻唑兰(MTT)比色法,对桦甘酯和桦丙酯进行了对HepG-2(肝癌细胞)活性分析。结果表明:桦甘酯和桦丙酯对HepG-2有专一促其凋亡的作用,其凋亡作用呈时间和浓度依赖。作用72 h后,半数抑制浓度(IC50)值分别为15.33和17.01μmol/L。桦甘酯和桦丙酯的IC50值与桦木醇的IC50值相比明显降低;对HepG-2细胞桦甘酯的IC50值约为桦木醇IC50值的1/6;桦丙酯的IC50值约为桦木醇IC50值的1/5,由此说明,桦甘酯和桦丙酯在抑制肿瘤细胞生长的活性方面明显优于桦木醇。

Preparation and characterization of icariin/PHBV drug delivery coatings on anodic oxidized titanium

A composite material was fabricated by applying a biodegradable drug delivery coating,consisting of poly（3-hydroxyburyrate-co-3-hydroxyvalerate）（PHBV） and icariin,to an anodic oxidized titanium plate.The coating was prepared by evaporating chloroform solution containing PHBV and icariin on the titanium plate under vacuum condition.Icariin/PHBV coated titanium plates significantly enhance the proliferation of MG-63 cells compared with the PHBV coated and anodic oxidized ones.Increased icariin contained in the coating displays an elevated influence on cell proliferation.The results show that icariin gradually releases from the coating to cells mainly through the phospholipid-based cellular membrane instead of the culture medium.The overall results suggest that the novel icariin/PHBV coating can be used to enhance the bioactivity of titanium based orthopedic implants.

Two New Phenolic Carboxylic Acid Esters from Opuntia vulgaris

Two new phenolic carboxylic acid esters n-butyl eucomate(1) and methyl eucomate (2) and six known compounds eucomic acid(3), 3-β-acetyl-taraxerol (4), friedelin(5),lupenone(6),methyl linoleate(7) and methyl oleate(8) were isolated from the stems of Opuntia vulgaris Mill(Cactaceae). Their structures were determined on the basis of spectral methods. Compounds 3,4,6,7,8 were isolated for the first time from this plant.

Ethyl and butyl acetate oxidation over manganese oxides

Mangenese oxides were synthesized using two new methods,a novel solvent‐free reaction and a reflux technique,that produced cryptomelane‐type products(K‐OMS‐2).Oxides were also synthesized using conventional methods and all specimens were applied to the oxidation of ethyl acetate and butyl acetate,acting as models for the volatile organic compounds found in industrial emissions.The catalysts were also characterized using N2adsorption,X‐ray diffraction,scanning electron microscopy,temperature programmed reduction and X‐ray photoelectron spectroscopy.Each of the manganese oxides was found to be very active during the oxidation of both esters to CO2,and the synthesis methodology evidently had a significant impact on catalytic performance.The K‐OMS‐2nanorods synthesized by the solvent‐free method showed higher activity than K‐OMS‐2materials prepared by the reflux technique,and samples with cryptomelane were more active than those prepared by the conventional methods.The catalyst with the highest performance also exhibited good stability and allowed90%conversion of ethyl and butyl acetate to CO2at213and202°C,respectively.Significant differences in the catalyst performance were observed,clearly indicating that K‐OMS‐2nanorods prepared by the solvent‐free reaction were better catalysts for the selected VOC oxidations than the mixtures of manganese oxides traditionally obtained with conventional synthesis methods.The superior performance of the K‐OMS‐2catalysts might be related to the increased average oxidation state of the manganese in these structures.Significant correlations between the catalytic performance and the surface chemical properties were also identified,hig-hlighting the K‐OMS‐2properties associated with the enhanced catalytic performance of the materials.?2018,Dalian Institute of Chemical Physics,Chinese Academy of Sciences.Published by Elsevier B.V.All rights reserved.

Measurement and modelization of VLE of binary mixtures of propyl acetate,butyl acetate or isobutyl acetate with methanol at pressure of 0.6 MPa

The vapor-liquid equilibrium of binary mixtures of propyl acetate, butyl acetate and isobutyl acetate with meth- anol has been determined at a constant pressure of 0.6 MPa. Results have been modeled with the Peng-Robinson equation, a traditional cubic equation of state widely employed in chemical industries, as well as with the perturbed-chain statistical associating fluid PC-SAFT theory of Gross-Sadowski. By correlation of the binary inter- action parameters of these equations, the measured vapor-liquid equilibrium data can be accurately predicted. Thus, this work shows that these models are able to represent the experimental data for systems with associating comoounds via hydrogen bonding.

Toxic effects of several phthalate esters on the embryos and larvae of abalone Haliotis diversicolor supertexta

As the most widely used plasticizers in the world, phthalate esters （PAEs） are potential endocrine disruption compounds （EDCs）. In the present study, the toxicity of dimethyl phthalate （DMP）, diethyl phthalate （DEP）, dibutyl phthalate （DBP）, di （2-ethylhexyl） phthalate （DEHP） on embryogenesis and larvae development of the marine univalve Haliotis diversicolor supertexta was examined in laboratory. The results show that the malformation of embryos appeared during the experiment, such as embryos died or lysed, small transparent flocculent rings studded on the periphery of the embryo, and the larvae could failed to hatch. In embryo toxic test, embryos incubated at the highest concentration of DMR DEP and DBP solutions showed significantly high abnormal rate compared with the control, while DEHP solutions displayed no significant difference. In larval toxic test, in all concentrations of DMP, DEP and DBP solutions, larval settlement rates were low significantly than that of the control. Similarly, DEHP solutions show nearly no effect on the larval settlement. The order of toxicity on embryos and larvae is DBP〉DEP〉DMP〉DEHE Being a simple and easy stimulation to indoor spawn, sensitive to environmental factors, and short culture time, the embryos of H. diversicolor supertexta can be used to indicate toxicity of the PAEs.

Modified graphite filled natural rubber composites with good thermal conductivity

The rubber composites with good thermal conductivity contribute to heat dissipation of tires. Graphite filled natural rubber composites were developed in this study to provide good thermal conductivity. Graphite was coated with polyacrylate polymerized by monomers including methyl methacrylate, n-butyl acrylate and acrylic acid. The ratios between a filler and acrylate polymerization emulsion and those between monomers were varied. Eight types of surface modification formulas were experimentally investigated. Modification formula can affect coating results and composite properties greatly. The best coating type was achieved by a ratio of1:1 between methyl methacrylate and n-butyl acrylate. The coating of graphite was thermally stable in a running tire. Filled with modified graphite, the tire thermal conductivity reached up to 0.517–0.569 W·m-1·K-1. In addition, the mechanical performance was improved with increased crosslink density, extended scorch time and short vulcanization time.

Optimization of coproduction of ethyl acetate and n-butyl acetate by reactive distillation

Based on a previous investigation,a simulation model was used for optimization of coproduction of ethyl acetate and n-butyl acetate by reactive distillation.An experimental setup was established to verify the simulated results.The effects of various operating variables,such as ethanol feed location,acetic acid feed location,feed stage of reaction mixture of acetic acid and n-butanol,reflux ratio of ethyl acetate reactive distillation column,and distillate to feed ratio of n-butyl acetate column,on the ethanol/n-butanol conversions,ethyl acetate/n-butyl acetate purity,and energy consumption were investigated.The optimal results in the simulation study are as follows:ethanol feed location,15th stage;acetic acid feed location,eighth stage;feed location of reaction mixture of acetic acid and n-butanol,eighth stage;reflux ratio of ethyl acetate reactive distillation column,2.0;and distillate to feed ratio of n-butyl acetate,0.6.

Nonisothermal Crystallization Kinetics of Poly(butylene adipate-co-terephthalate) Copolyester

Nonisothermal crystallization behavior of poly(butylene adipate-co-terephthalate)(PBAT) synthesized via direct esterification and polycondensation reactions was investigated by the differential scanning calorimetry(DSC).The Avrami equation modified by Jeziorny and the Z.S.Mo equation were employed to describe the non-isothermal crystallization kinetics of copolyester samples.The test results showed that the Avrami equation was successful in describing nonisothermal crystallization process of PBAT copolyesters.PBAT copolyester could give birth to secondary crystallization.The crystallization parameter(Zc) increased with an increasing cooling rate and the Avrami exponent(n) was around 2.3.For a given cooling rate,the value of Zc demonstrated a sagging trend with an increase in adipic acid(AA) content.The equation proposed by Z.S.Mo was successful in describing the nonisothermal crystallization kinetics of PBAT copolyesters.

THERMAL PROPERTY, MISCIBILITY AND CRYSTALLIZATION BEHAVIOR OF POLY(3-HYDROXYBUTYRATE-co-3-YDROXYHEXANOATE) AND POLY(BUTYLENE SUCCINATE-ADIPATE) (PHBHHX/PBSA) BLENDS

Blends of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) and poly(butylene succinate-adipate) (PBSA), both biodegradable semicrystalline polyesters, were prepared with the ratio of PHBHHx/PBSA ranging from 80/20 to 20/80 by melt mixing method. Differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), dynamic mechanical thermal analysis (DMA), polarizing optical microscopy (POM) and wide angle X-ray diffractometer (WAXD) were used to study the miscibility and crystallization behavior of PHBHHx/PBSA blends. Experimental results indicate that PHBHHx is immiscible with PBSA as shown by the almost unchanged glass transition temperature and the biphasic melt.

Study on Modification of Octyl-α-Cyanoacrylate Medical Adhesive

Objective:In order that the adhesive character could be improved to modify the octyl-α-cyanoacrylate(OCA) medical adhesive.Methods:Suitable modifiers involving polycaprolactone(PCL),dibutyl phthalate (DBP),dioctyl phthalate(DOP) and poly octyl methacrylat(POMA) have been chosen to modify the OCA adhesive,then tensile shear strength and adhesive strength are tested to evaluate the bond character of adhesives.Results:The PCL group's tensile shear strength and adhesive strength in normal temperature are descended while the other groups'are all enhanced.Conclusion:The modification of properties of the other groups is effectively promoted in the aspect of the bond character,except the PCL group treated in normal temperature and the PCL modified group treated by rectification get a best improvement in the agglutinate intention, while the stability is expected to be improved.

Study on Structure and Crystallinity of A New Biodegradable Aliphatic-Aromatic Copolyester

A series of biodegradable aliphatic-aromatic copolyesters, poly(butylene terephthalate-co-butylene adipate-co- ethylene terephthalate-co-ethylene adipate) (PBATE), were synthesized from terephthalic acid (PTA), adipic acid (AA), 1,4-butanediol (BG) and ethylene glycol (EG) through direct esterification and polycondensation. The sequence structure and crystallinity of the copolyester were investigated by 1H NMR spectroscopy and the wide-angle X-ray diffractometry (WAXD). The analytical results showed that the PBATE copolyester was a random copolymer and the composition of PBATE copolyester was almost consistent with the feed molar ratios. The crystal structure of PBATE copolyester belonged to the triclinic crystalline system; The variation in melting point of the synthesized PBATE copolyester agreed well with the estimation obtained by the Flory equation and was applicable to the random copolymer.

STUDY ON BIODEGRADABILITY OF POLY (3-HYDROXYBUTYRATE-co-3-HYDROXYVALERATE)/ORGANOPHILIC MONTMORILLONITE NANOCOMPOSITES

Poly (3-hydroxybutyrate-co-3-hydroxyvalerate)/Organophilic montmorillonite (PHBV/OMMT) nanocomposites were prepared and the biodegradability of the PHBV/OMMT nanocomposites was studied by a cultivation degrading method in soil suspension. The relationship between structure and biodegradability of PHBV/OMMT nanocomposites was investigated. The results showed that the biodegradability of PHBV/OMMT nanocomposites decreased with increasing amount of OMMT and it was related to the number of PHBV degrading microorganisms in degradation environment, the anti-microbial property of OMMT and the degree of crystallinity of the nanocomposites.

Contamination of Phthalate Esters in Vegetable Agriculture and Human Cumulative Risk Assessment

Phthalate esters （PAEs）, which can disturb human endocrine system, have been widely detected in vegetable greenhouse agriculture in China. To investigate the effects of environmental factors on PAEs in soils, pollution sources were identified, and the cumulative risks of PAEs to humans through vegetables in the diet were evaluated in this study. Ninety-eight vegetable samples were collected from 10 markets along with 128 vegetable and 111 soil samples from agricultural greenhouses and open field. All soil and vegetable samples were contaminated with PAEs, and the total concentrations of the 5 PAEs, including dimethyl phthalate （DMP）, diethyl phthalate （DEP）, di-iso-butyl phthalate （DiBP）, di-n-butyl phthalate （DnBP）, and di-2-ethylhexyl phthalate （DEHP）, were in the ranges of 0.26-2.53 mg kg-1 for soils and 0.95-8.09 mg kg-1 for vegetables. Three components extracted from principle component analysis could explain 51.2%, 19.8%, and 15.3% of the total variance of the 5 PAEs in soils, which may represent three major sources of PAEs, i.e., wastewater irrigation, application of fertilizers and pesticides, and plastic film. Long-term greenhouse cultivation could accumulate DEHP in soils, and a higher soil FeOx content reduced the DnBP concentration. Based on a survey of vegetables in the diet, the hazard index of PAEs was 〈 0.15 for individuals in different cities. The exposure of PAEs through vegetable intake was higher than the total exposure from other food stuffS, inhalation, and dermal absorption. More attention should be g!ven to controlling PAEs in greenhouse vegetables.

Electrical conductivities of carbon nanotube-filled polycarbonate/polyester blends

Carbon nanotube (CNT)-filled polycarbonate (PC)/poly(butylene terephthalate) (PBT) and polycarbonate (PC)/poly(ethylene terephthalate) (PET) blends containing 1 wt% CNTs over a wide range of blend compositions were prepared by melt mixing in a torque rheometer to investigate the structure-electrical conductivity relationship. Field emission scanning electron microscopy was used to observe the blend morphology and the distribution of CNTs. The latter was compared with the thermodynamic predictions through the calculation of wetting coefficients. It was found that CNTs are selectively localized in the polyester phase and conductive blends can be obtained over the whole composition range (20 wt%, 50 wt% and 80 wt% PBT) for CNT-filled PC/PBT blends, while conductive CNT-filled PC/PET blends can only be obtained when PET is the continuous phase (50 wt%, 80 wt% PET). The dramatic difference in the electrical conductivity between the two types of CNT-filled PC/polyester blends at a low polyester content (20 wt%) was explained by the size difference of the dispersed phases on the basis of the transmission electron microscope micrographs.