Oxonitrogenated Derivatives of Eremophilans and Eudesmans: Antiproliferative and Anti-Trypanosoma cruzi Activity

Cancer is one of the most important causes of death worldwide. Solid tumors represent the vast majority of cancers (>90%), and the chemotherapeutic agents used for their treatment are still characterized by variable efficacy and toxicity. Sesquiterpenes are a group of natural compounds that have shown a wide range of biological activities, including cytotoxic and antiparasitic activity, among others. The antiproliferative activity of natural sesquiterpenes, tessaric acid, ilicic acid, and ilicic alcohol and their semisynthetic derivatives against HeLa, T-47D, WiDr, A549, HBL-100, and SW1573 cell lines were evaluated. The effect of the compounds on Trypanosoma cruzi epimastigotes was also assessed. The selectivity index was calculated using murine splenocytes. Derivatives 13 and 15 were the most antiproliferative compounds, with GI₅₀ values ranging between 5.3 (±0.32) and 14 (±0.90) μM, in all cell lines tested. The presence of 1,2,3-triazole groups in derivatives 15–19 led to improvements in activity compared to those corresponding to the starting natural product (3), with GI₅₀ values ranging between 12 (±1.5) and 17 (±1.1) μM and 16 being the most active compound. In relation to the anti-T. cruzi activity, derivatives 7 and 16 obtained from tessaric acid and ilicic acid were among the most active and selective compounds with IC₅₀ values of 9.3 and 8.8 µM (SI = 8.0 and 9.4), respectively.     

Mulberry Ethanol Extract and Rutin Protect Alcohol-Damaged GES-1 Cells by Inhibiting the MAPK Pathway

Mulberry extract has been proven to have the effect of resisting alcohol damage, but its mechanism is still unclear. In this study, the composition of mulberry ethanol extract (MBE) was identified by LC-MS/MS and the main components of MBE were ascertained by measuring. Gastric mucosal epithelial (GES-1) cells were used to elucidate the mechanism of MBE and rutin (the central part of MBE) helped protect against alcohol damage. The results revealed that phenolics accounted for the majority of MBE, accounting for 308.6 mg/g gallic acid equivalents and 108 substances were identified, including 37 flavonoids and 50 non-flavonoids. The treatment of 400 μg/mL MBE and 320 μM rutin reduced early cell apoptosis and the content of intracellular reactive oxygen species, malondialdehyde and increased glutathione. The qPCR results indicated that the MBE inhibits the expression of genes in the mitogen-activated protein kinase (MAPK) pathway, including p38, JNK, ERK and caspase-3; rutin inhibits the expression of p38 and caspase-3. Overall, MBE was able to reduce the oxidative stress of GES-1 cells and regulated apoptosis-related genes of the MAPK pathway. This study provides information for developing anti-ethanol injury drugs or functional foods.     

热处理条件对PVA薄膜阻氢性能的影响

采用XRD测定了PVA薄膜在不同热处理条件下的结晶度,并用自行设计的渗氢系数测量系统研究了在不同热处理条件下的PVA薄膜阻氢性能的变化规律。结果表明,PVA薄膜的热处理温度越高,其结晶度越高,越有利于提高PVA薄膜的阻氢性能,但热处理温度宜选择在180℃以下,以防止PVA薄膜热降解,另一方面,在PVA的玻璃化转变温度以下进行热处理同样能够提高PVA薄膜的阻氢性能,而醇解度较低的PVA薄膜在玻璃化转变温度以下经热处理后的阻氢性能提高的幅度较大。     

甲基紫掺杂聚乙烯醇薄膜材料红光多重全息存储

甲基紫掺杂聚乙烯醇薄膜材料在两束相干光照射下生成相位光栅.当改变一束相干光光程,通过监测相位光栅的一级衍射信号强度的变化,可以检测相位光栅的生长和擦除过程.在此实验基础上,讨论了甲基紫掺杂聚乙烯醇薄膜材料多重全息存储的原理与结果.     

Theoretical investigation of imidazolium based ionic liquid/alcohol mixture: a molecular dynamic simulation

In this work, molecular dynamic simulation of the mixture of imidazolium based ionic liquids with alcohols is implemented in order to investigate mixing excess properties and some structural and physical properties of the mixture. Excess volumes and enthalpies are evaluated for 11 different mole fractions of ionic liquids at each 0.1, in the range of 0 to 1. Radial distribution function, cohesive energy density, potential of mean force, solvation energy, and diffusion coefficient are reported and analysed. The effects of the cationic alkyl chain length, in comparison with changes of the anions, on these properties are reported. Results reveal that the methanol molecule participates with its hydrophilic characteristics in the mixing process and tends to aggregate around anion part of the ionic liquids, especially in the case of Cl.     

Stoichiometry,Association Constant,and Solvation Model of Chiral Hydroxyfuranones in the Presence of Pirkle's Alcohols

ABSTRACT

(S)-(+)-Dihydro-3-hydroxy-4,4-dimethyl-2(3H)-furanone, (R)-(-)-dihydro-3-hydroxy-4,4-dimethyl-2(3H)-furanone, (S)-(-)-dihydro-4-hydroxy-2(3H)-furanone, and (S)-(-)-5-hydroxymethyl-2(5H)-furanone in the presence of pure enantiomers of 2,2,2-trifluoro-1-(9-anthryl)ethanol were studied by ¹H NMR in deuterated chloroform solutions. Experimental Job's plots suggest that the resulting solvates are formed with one molecule of solute and one of the chiral solvating agent. From the magnitude of the association constant determined for (S)-(+)-dihydro-3-hydroxy-4,4-dimethyl-2(3H)-furanone in the presence of (R)-(-)-2,2,2-trifluoro-1-(9-anthryl)ethanol (1.26 ± 0.09 M^?1), it is inferred that the solvate is weak and cannot be isolated at 298 K. The correlation between the magnitude of induced chemical shifts, NOESY maps, and the known configuration of solutes and chiral solvating agents suggests that intermolecular hydroxyl-hydroxyl interaction is the primary interaction. Accordingly, the secondary interaction might occur between benzylic-hydrogen of the chiral solvating agent and the carbonyl- or furan ring-oxygen atoms of the solute.     

Preparation of Poly (L-lactic Acid) Microsphere

Poly (L-lactic acid) (PLLA) microspheres were prepared by a solvent evaporation method based on an oil/water emulsion. The effect of the mass ratio of PLLA and poly(vinyl alcohol) (PVA) on the formation of the microspheres was discussed, and the influence of extraction speed of dichloromethane on the microsphere morphology was also studied. Moreover, the influences of the PLLA concentration and the volume ratio of water phase to dichloromethane phase were investigated. The results showed that stable microspheres can be obtained under the conditions that the mass ratio of PLLA to PVA is 20:1. Porous microspheres were obtained under faster evaporating speed of dichloromethane. The microsphere size increased with increasing PLLA concentration. The microsphere size also increased with the increase of the volume ratio of water phase to dichloromethane phase.     

Isotope Effects in the Electrochemical Reduction of Oxalic Acid-D2 and Benzoic Acid-D

Abstract

The electrochemical reduction of model carboxylic acid at lead cathodes in deuterated media was studied for potential use in the synthesis of special deuterated compounds.

Oxalic acid-d₂ in D₂O gives good yields of glyoxylic acid-d₂. An unexpected large isotope effect of 5.3 ± 1.7 was found in this reaction, leading to significant depletion of deuterium content in the aldehyde group.

Benzoic acid-d in CD₃OD/diluted D₂SO₄ yields benzyl alcohol-d, 7,7-d₂. The isotope effect of 2.4 ± 1.0 is within the expected range. No deuterium is incorporated into the aromatic nucleus. Essentially unlabelled benzyl alcohol is obtained in CD₃OH/dil. H₂SO₄.     

Microstructure and Thermal and Tensile Properties of Poly(vinyl alcohol) Nanocomposite Films Reinforced by Polyacrylamide Grafted Cellulose Nanocrystals

Abstract

Polyacrylamide grafted cellulose nanocrystals (CNC-g-PAM) were incorporated into poly(vinyl alcohol) (PVA) by a solution casting method to fabricate nanocomposite films with enhanced thermal and tensile properties. The microstructure and the thermal and tensile properties of the PVA/CNC-g-PAM nanocomposite films were investigated as a function of CNC-g-PAM content. Infrared spectroscopy corroborated the presence of hydrogen bonds between PVA and the PAM on the surface of the CNC. Polarized optical microscopy and scanning electron microscopy revealed good dispersion of the CNC-g-PAM in the PVA matrix and good interfacial compatibility. Accordingly, the initial degradation temperature of the nanocomposite films was elevated slightly compared to pristine PVA film. The glass transition temperature, melting temperature, and crystallinity of the PVA also varied slightly after the incorporation of the CNC-g-PAM. At both 0% and 50% RH, the nanocomposite films showed an obvious increase of elastic modulus, no apparent change of breaking strength and a drastic reduction of elongation at break with increasing CNC-g-PAM content.     

Synthesis and Properties of Cupric Sulphate Doped Polyvinyl Pyrrolidone (PVP) Solutions

The optical, electrical and acoustical properties of polymer solutions based on polyvinyl pyrrolidone (PVP) doped with cupric sulphate (CuSO₄) were studied. The polymer solutions were prepared by varying the concentration of Cu in the PVP using a simple chemical route. The UV-visible spectroscopy results showed that the optical absorbance decreased with an increase in wavelength from 300 to 700 nm. The optical band gaps were found to decrease with addition of the Cu salt in the polymer. The refractive index also showed significant variation with the doping of the CuSO₄. The electrical conductivity of the polymer solutions was found to increase with temperature as well as concentration of Cu while the activation energy of electrical conduction decreased with concentration of Cu. The ultrasonic velocities of the polymer solutions were measured at a frequency of 1 MHz using an ultrasonic interferometer. The ultrasonic velocity and surface tension were increased while the adiabatic compressibility, acoustic impedance and intermolecular free length, the average distance between the surfaces of the coils of adjacent molecules, were decreased with increase in the concentration of CuSO₄ in the PVP.