Chemical Composition and Antioxidant Activity of Essential Oil from Fruit of Schisandra perulata

Chemistry of Natural Compounds -     

Comparison of Yield,Chemical Composition and Antimicrobial Activity of Distichochlamys citrea Rhizome Essential Oils Obtained by Different Extraction Methods

Moscow University Chemistry Bulletin - Hydrodistillation (HD), steam distillation (SD) and microwave-assisted hydrodistillation (MAHD) extraction methods were assessed for their effects on yield,...     

Microstructure and magnetic properties of CoFe_2O_4 thin films deposited on Si substrates with an Fe_3O_4 under-layer

The microstructure and magnetic properties of cobalt ferrite thin films deposited by the sputtering method on an Fe3O4 under-layer were investigated at different post-annealing temperatures.Results show that the Fe3O4 under-layer can accelerate the grain growth of cobalt ferrite films due to the phase transformation of the Fe3O4 under-layer at about 400°C-500°C.By introducing the Fe3O4 under-layer,cobalt ferrite nanocrystalline thin films with high coercivity can be obtained at lower post-annealing temperat...     

Low-temperature liquid extraction as a method of the pretreatment of phenol samples for reversed-phase HPLS

A new procedure was developed for the liquid—liquid extraction of phenols from aqueous solutions With acetonitrile. It is based on the ability of aqueous acetonitrile systems to form immiscible phases in the temperature range 271—269 K. The resulting duration of analysis is 40–45 min, the partition coefficient is 45–140, and the recovery is 97.8–99.2%. The procedure was proved applicable for sample pretreatment followed by determination by reversed-phase HPLC.     

Wasser

Analytical and Bioanalytical Chemistry -     

Variations in the Concentrations of Cu and Zn and in the Ratio of Cu to Zn in Whole Blood and Hair Samples from Hepatocellular Carcinoma Patients and from Healthy Controls in Taiwan

An atomic absorption spectrophotometer was used to determine concentrations of copper and zinc and the ratio of Cu to Zn in samples of whole blood and hair from hepatocellular carcinoma (HCC) patients (n=51) and from healthy controls (n=50) in Taiwan. Our results indicate that the HCC patients have higher copper concentrations and higher ratios of Cu to Zn than do the healthy controls both in whole blood and hair samples, but only the concentration of copper and the ratio of Cu to Zn in whole blood were significantly different (p<0.001 and p<0.05). Conversely, a lower concentration of zinc was found in whole blood and hair samples of HCC patients. Similarly, only the concentration of zinc in whole blood showed a significant difference (p<0.001). We concluded that the whole blood concentrations of copper and zinc and the ratio of Cu to Zn seemed to have a higher correlation with HCC. Thus, we suggest that a sample of whole blood may be a more suitable diagnostic sample than is a hair sample for HCC.     

Encapsulated ultrafine and highly dispersed molybdenum dioxide nanoparticles in hollow mesoporous silica spheres as an efficient epoxidation catalyst for alkenes

A facile post-synthetic strategy was developed to functionalize the preformed hollow mesoporous silica spheres by encapsulating the molybdenum dioxide (MoO₂) nanoparticles inside the interior cavity. Hollow mesoporous silica spheres were prepared and employed as carriers, and the encapsulation of MoO₂ nanoparticles was achieved through a one-pot hydrothermal protocol. After characterization, the encapsulated MoO₂ nanoparticles were certified to be ultrafine and highly dispersed, which greatly promoted the catalytic activity. The as-prepared catalysts were utilized in epoxidation of alkenes and exhibited as a promising catalyst in this reaction. After reacting for 10 h, the optimal catalyst MoO₂@SiO₂-1 achieved a conversion above 95% and selectivity above 95%, respectively. Moreover, the catalysts also exhibited good reusability, conversion of 78% and selectivity of 89% (reaction time 4 h) were still obtained after recycling for 5 times. Meanwhile, the employed facial and efficient hydrothermal approach could be expanded to other molybdenum modified heterogeneous catalysts in various applications.     

Markhacanasin C,cycloartane triterpenoid from the leaves of Markhamia stipulata var. canaense V.S. Dang

One new cycloartane triterpenoid, named markhacanasin C (1), together with three known triterpenoids, oleanolic acid (2), ursolic acid (3) and 6β,19α-dihydroxyursolic acid (4) were isolated by various chromatographic methods from the most cytotoxic fraction of the ethyl acetate extract of Markhamia stipulata var. canaense V.S. Dang leaves. Among them, 4 was reported for the first time from the genus Markhamia, while 2 and 3 were found for the first time from this species. Their structures were elucidated by IR, UV, HR-ESI-MS and NMR experiments. The cytotoxicity of isolated compounds (3 and 4) against three human cancer cell lines (HeLa, HepG2, and MCF-7) were evaluated. At the concentration of 100 μg/mL, 3 exhibited significant cytotoxic activity (86.36 ± 3.69%).     

高温热处理气氛对低氟MOD法制备YBCO超导薄膜的影响研究

金属有机物沉积法(MOD)制备YBa2Cu3O7-x(YBCO)涂层导体是最具有商业前景的方法之一.本文使用环烷酸铜代替三氟乙酸铜,降低了前驱液中大约50%的氟含量.然后在带有缓冲层(Y2O3/YSZ/CeO2)的Ni-5at.%W基带上采用MOD法制备了YBCO薄膜并系统研究了高温热处理过程中气体流速和氧分压对YBC...