scholarly journals Microfluidic Preparation of Liposomes Using Ethyl Acetate/n-Hexane Solvents as an Alternative to Chloroform

2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Eunhye Yang ◽  
Hyunjong Yu ◽  
Jun-Young Park ◽  
Kyung-Min Park ◽  
Pahn-Shick Chang

Although liposomes have been used as a nutrient delivery carrier in the pharmaceutical, cosmetic, and food industries, they still suffer from the critical issue caused by the use of halogenated solvents (e.g., chloroform), which may be harmful to humans. Nonhalogenated solvents have been screened as candidate substitutes for chloroform based on their physicochemical properties. However, none of the candidates examined to date could form stable inverted micelles when used alone. Here, to obtain physicochemical properties similar to chloroform, combined mixtures were prepared using various ratios of each candidate. Based on the results of random combination trials with numerous candidates, ethyl acetate: n-hexane = 4 : 1(v/v) was selected as the optimum ratio because it could form stable inverted micelles and a transparent liposome solution without phase separation. The ethyl acetate and n-hexane mixture are a potential substitute for chloroform, which may resolve concerns regarding the toxicity of residual halogenated solvents in lipid nanovesicles.

2019 ◽  
Vol 293 ◽  
pp. 35-49 ◽  
Author(s):  
Wiktor Matysiak ◽  
Tomasz Tański ◽  
Weronika Smok

Today, one of the most popular nanomaterials are thin nanofibrous layers, which are used in many fields of industry, eg electronics, optics, filtration and the textile industry. They can be produced by various methods, such as drawing, template synthesis, molecular self-assembly or phase separation method, but the most common method is electrospinning from a solution or melts. Electrospinning is gaining more and more interest due to its versatility, simplicity and economy as well as the possibility of producing fibers from various types of polymeric, ceramic and metalic materials. Nanofibrous layers produced by this method are characterized by high quality and the desired physicochemical properties.


Author(s):  
Caixia Miao ◽  
Fengjiao Wang ◽  
Guilin Zhou ◽  
Hongmei Xie ◽  
Zhaojie Jiao ◽  
...  

Abstract The mesoporous Ni20/Al-KIT-6 (denoted as N20AxK) catalysts with different Al content (1–9 wt%) were prepared, metal Ni and KIT-6 modified by Al were used as active component and support, respectively. The physicochemical properties of the prepared N20AxK catalysts were characterized by H2-TPR, XRD, BET, TEM, and H2-TPD. The catalytic hydrodeoxygenation(HDO) performance of N20AxK catalysts was evaluated by ethyl acetate catalytic HDO. The results show that the catalytic HDO performance of the prepared N20AxK catalysts is related to the adsorption and activation performance for H2 molecules, as well as the dispersion of matal Ni active components. N20A5K catalyst shows the best H2 adsorption property and Ni dispersion. N20A5K catalyst presents superior catalytic HDO performance. At 300 °C and atmospheric pressure, the conversion of ethyl acetate and ethane selectivity of N20A5K catalyst are 99.3 % and 97.4 %, respectively. Besides, the N20A5K catalyst exhibits good stability.


Author(s):  
YURI S. AVLASEVICH ◽  
TIMOUR A. CHEVTCHOUK ◽  
VALERY N. KNYUKSHTO ◽  
OLEG G. KULINKOVICH ◽  
KONSTANTIN N. SOLOVYOV

Novel water-soluble tetraarylporphyrin-labelled polymers have been synthesized by the reaction of bromoalkyl-containing poly(N-isopropylacrylamides) with 5-(4-pyridyl)-10,15,20-tri(4-methoxyphenyl) porphyrin. Corresponding Zn -porphyrin-containing polymers have also been prepared. Phase transition diagrams show that aqueous polymer solutions exhibit phase separation upon heating. Absorption spectra of the porphyrin-labelled polymers have been recorded in water and organic solvents. It is found that the absorption bands in aqueous polymer solutions are broadened and shifted bathochromically, the peak intensity of the Soret band in the polymer spectra being strongly lowered in water. Fluorescence properties of the polymers are briefly reported.


2021 ◽  
Vol 12 ◽  
Author(s):  
Guangyang Jiang ◽  
Longzhan Gan ◽  
Xiaoguang Li ◽  
Juan He ◽  
Shihao Zhang ◽  
...  

The present study sought to isolate a novel exopolysaccharide (EPS-F2) from Enterococcus sp. F2 through ethanol precipitation, anion-exchange, and gel-filtration chromatography and characterize the physicochemical properties by spectral techniques. EPS-F2 was identified as a neutral homo-exopolysaccharide composed of only glucose with a high molecular weight of 1.108 × 108 g/mol. It contained →6)-α-D-Glcp-(1→ linkage in the main chain and →3, 6)-α-D-Glcp-(1→ branch chain). Moreover, EPS-F2 possessed excellent thermal stability (266.6°C), water holding capacity (882.5%), oil holding capacity (1867.76%), and emulsifying activity against various edible oils. The steady shear experiments exhibited stable pseudo plasticity under various conditions (concentrations, temperatures, and pHs). The dynamic oscillatory measurements revealed that EPS-F2 showed a liquid-like behavior at a low concentration (2.5%), while a solid-like behavior at high concentrations (3.0 and 3.5%). Overall, these results suggest that EPS-F2 could be a potential alternative source of functional additives and ingredients and be applied in food industries.


2020 ◽  
Vol 98 (3) ◽  
pp. 158-163 ◽  
Author(s):  
Toren Hynes ◽  
David S. Hall ◽  
Alexander W.H. Speed ◽  
Jason D. Masuda ◽  
J.R. Dahn

3-R-1,4,2-dioxazol-5-ones are a class of compounds that are increasingly finding diverse uses, including as regioselective amidation reagents and as electrolyte additives that enable long cycling lifetimes in rechargeable lithium-ion batteries. Conventional methods for their synthesis tend to be slow and time-consuming, requiring isolation and thorough drying of a hydroxamic acid intermediate, followed by a separate cyclization step with N,N′-carbonyldiimidazole. Furthermore, the cyclization is typically performed in dichloromethane, an environmentally harmful solvent. This work demonstrates a new one-pot method for the synthesis of these compounds that eliminates the need for isolation of the intermediate or the use of halogenated solvents. The reaction is mainly performed using environmentally benign ethyl acetate and a relatively small amount of N,N-dimethylformamide. The reaction proceeds readily at room temperature and requires no expensive metal catalysts to function.


2012 ◽  
Vol 550-553 ◽  
pp. 1862-1865
Author(s):  
Yan Zhang ◽  
Li Yang ◽  
Lin Wang

The chemical constituents were isolated from the ethyl acetate fraction from ethanol extract of Selaginella doederleinii Hieron by column chromatography on silica gel and Sephadex LH-20. The chemical structures of six biflavones were elucidated on the basis of physicochemical properties and spectroscopic data as amentoflavone (1), robustaflavone 7,4',7''-o-trimethyl ether (2), heveaflavone (3), podocarpusflavone A (4), robustaflavone 4',4'''-o-dimethyl ether (5) and robustaflavone 4'-o-methyl ether (6). Biflavones 2, 4 and 5 were obtained from Selaginella doederleinii Hieron for the first time.


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