Abeliaside,a new phenolic glucoside from Abelia triflora

A new phenolic glucoside, abeliaside, along with four known compounds, 5,6,7,4′-tetrahydroxy flavones, caffeic acid, 4-O-caffeoylquinic acid and caffeic acid glucoside, was isolated from the leaves of Abelia triflora R. Br. (Caprifoliaceae). The structure of the new compound was elucidated by different spectroscopic techniques. Compounds 1–5 were assayed for their anticancer activities against two cancerous human cell lines, MCF-7 and PC-3 cells, and normal Vero cell line using the crystal violet staining method. From the results it could be seen that caffeic acid possessed the highest anticancer effect against MCF-7 (IC₅₀: 17 μg/mL) and PC-3 (IC₅₀: 20.1 μg/mL) compared to vinblastine sulphate as reference drug (IC₅₀: 4.6, 2.8 μg/mL). The other compounds showed weak anticancer activity on both cell lines.     

Synthesis of Arylated Benzofurans by Regioselective Suzuki–Miyaura Cross‐Coupling Reactions of 2,3‐Dibromobenzofurans‐ and 2,3,5‐Tribromobenzofurans

Arylated benzofurans were prepared by regioselective Suzuki–Miyaura cross‐coupling reactions of 2,3‐dibromobenzofuran. The reactions proceeded with very good site‐selectivity in favor of the more electron deficient position 2. The Suzuki–Miyaura reactions of 2,3,5‐tribromobenzofuran also proceeded in favor of position 2.     

One pot three component synthesis of spiro [indolo-3,10’-indeno[1,2-b]quinolin]-2,4,11’-triones as a new class of antifungal and antimicrobial agents

A simple and efficient three component procedure has been developed for the synthesis of highly substituted spiro[indolo-3,10'-indeno[1,2-b]quinolin]-2,4,11'-triones by one pot three component condensation of enaminones, isatin and indane-1,3-dione in ethanol:water (1:1) in presence of ceric ammonium nitrate (CAN) as catalyst. This method provides several advantages such as lesser reaction time, high yield of products and operational simplicity. The antimicrobial activity of some of the compounds has been investigated against six microbial strains, some of the tested compounds showed good antimicrobial activity.     

Chemical spray pyrolysis deposition of zinc sulphide thin films using ethylenediaminetetraacetic acid disodium salt complexant

Journal of Solid State Electrochemistry - Zinc sulphide thin films were deposited by chemical spray pyrolysis technique. The films were deposited at substrate temperatures of 300, 350 and...     

Simple chemical route for nanorod-like cobalt oxide films for electrochemical energy storage applications

We used a simple chemical synthesis route to deposit nanorod-like cobalt oxide thin films on different substrates such as stainless steel (ss), indium tin oxide (ITO), and microscopic glass slides. The morphology of the films show that the films were uniformly spread having a nanorod-like structure with the length of the nanorods shortened on ss substrates. The electrochemical properties of the films deposited at different time intervals were studied using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS). The film deposited after 20 cycles on ss gave the highest specific capacity of 67.6 mAh g^?1 and volumetric capacity of 123 mAh cm^?3 at a scan rate 5 mV s^?1 in comparison to 62.0 mAh g^?1 and 113 mAh cm^?3 obtained, respectively, for its counterpart on ITO. The film electrode deposited after 20 cycles on ITO gave the best rate capability and excellent cyclability with no depreciation after 2000 charge–discharge cycles.     

On the receptivity and nonparallel stability of traveling disturbances in rotating-disk flow

The generation and evolution of small amplitude long wavelength traveling disturbances in rotating-disk flow is the subject of this paper. The steady rotational speed of the disk is perturbed so as to introduce high-frequency oscillations in the flow field. Secondly, we introduce surface imperfections on the disk such as roughness elements. The interaction of these two disturbances will generate the instability waves whose evolution is governed by parabolic partial differential equations which are solved numerically. It is found that, for the class of disturbances considered here (wavelength on the order of Reynolds number), eigensolutions exist which decay or grow algebraically in the radial direction. However, these solutions grow only for frequencies larger than 4.58 times the steady rotational speed of the disk. The computed receptivity coefficient shows that there is an optimum size of roughness for which these modes are preferentially excited. The width of these roughness elements in the radial direction is about 0.1r ₀ ^* where r ₀ ^* is the radial location of the roughness. It is also found that the receptivity coefficient is larger for a negative spanwise wave number than for a positive one. The cumulative wave pattern produced from the roughness site shows that the typical wave angles for these disturbances are about –26° with about seven waves around the circumference. This is in contrast with the wave angles of 10°–14° found for the 30 or so inviscid cross-flow vortices.This work was sponsored by NASA Langley Research Center under Contracts NAS1-18240 (P.B. and M.R.M.) and NAS1-18605 (P.H.).     

In vitro studies of carbon fiber microbiosensor for dopamine neurotransmitter supported by copper-graphene oxide composite

A composite was prepared from copper and graphene oxide (Cu-GO) by in-situ chemical reduction of a mixture containing GO and Cu(II) ions with potassium borohydride. The morphology and structure of the composite were confirmed by various physicochemical techniques. The materials were used in a tyrosinase-based microbiosensor where the enzyme is immobilized in a biocompatible matrix consisting of poly(ortho-phenylene diamine) and Cu-GO. The composite was deposited on the surface of an 8-μm thick carbon fiber microelectrode. The role of each component in the sensing layer was systematically investigated with respect to the analytical performance of the system. In its optimal configuration, the biosensor demonstrated (a) a sensitivity of 6.1?±?3 nA mM^-1 dopamine (DA), (b) a linear response to DA (with a Michaelis-Menten constant of 0.29?±?0.03 mM), (c) good selectivity over ascorbic acid and uric acid, and (d) a high blocking capacity (112.2?±?2 mM) for ascorbic acid.

Radiofluorination of 2-fluoropyridines by isotopic exchange with [<Superscript>18</Superscript>F]fluoride

In homoaromatic systems, isotopic exchange (¹⁸F/¹⁹F) was previously (J Label Compd Radiopharm 18(12):1721–1730 [2], J Chem Soc Perkin Trans 1(3):295–298 [3]) proven to be advantageous, yet in general specific activity is thought to be low. For heteroaromatic systems, in particular, very few examples are published regarding the ¹⁸F-labelling of 2-substituted pyridines (J Label Compd Radiopharm 42:975–985 [9]). Therefore, in 2-fluoropyridines, we decided to study the ¹⁸F labelling by isotopic exchange (¹⁸F/¹⁹F). The radiochemical yield for 2-fluoropyridine was 90 ± 2%. Even if 2-fluoropyridine was substituted by an electron-donating group such as a methyl or a methoxy group, radiochemical yields were 80 ± 1 and 78 ± 1%, respectively. Although in benzenes, these substituents are known to decrease nucleophilic substitutions by ¹⁸F-Fluoride significantly. Moreover, by choosing appropriate concentrations of 2-fluoropyridines, reasonably high specific activities up to 10 GBq/μmol were obtained.     

Influence of biological media on the structure and behavior of ferrocene-containing cationic lipid/DNA complexes used for DNA delivery

Biological media affect the physicochemical properties of cationic lipid-DNA complexes (lipoplexes) and can influence their ability to transfect cells. To develop new lipids for efficient DNA delivery, the influence of serum-containing media on the structures and properties of the resulting lipoplexes must be understood. To date, however, a clear and general picture of how serum-containing media influences the structures of lipoplexes has not been established. Some studies suggest that serum can disintegrate lipoplexes formed using certain types of cationic lipids, resulting in the inhibition of transfection. Other studies have demonstrated that lipoplexes formulated from other lipids are stable in the presence of serum and are able to transfect cells efficiently. In this article, we describe the influence of serum-containing media on lipoplexes formed using the redox-active cationic lipid bis(n-ferrocenylundecyl)dimethylammonium bromide (BFDMA). This lipoplex system promotes markedly decreased levels of transgene expression in COS-7 cells as serum concentrations are increased from 0 to 2, 5, 10, and 50% (v/v). To understand the cause of this decrease in transfection efficiency, we used cryogenic transmission electron microscopy (cryo-TEM) and measurements of zeta potential to characterize lipoplexes in cell culture media supplemented with 0, 2, 5, 10, and 50% serum. Cryo-TEM revealed that in serum-free media BFDMA lipoplexes form onionlike, multilamellar nanostructures. However, the presence of serum in the media caused disassociation of the intact multilamellar lipoplexes. At low serum concentrations (2 and 5%), DNA threads appeared to separate from the complex, leaving the nanostructure of the lipoplexes disrupted. At higher serum concentration (10%), disassociation increased and bundles of multilamellae were discharged from the main multilamellar complex. In contrast, lipoplexes characterized in serum-free aqueous salt (Li(2)SO(4)) medium and in OptiMEM cell culture medium (no serum) did not exhibit significant structural changes. The zeta potentials of lipoplexes in serum-free media (salt medium and cell culture medium) were similar (e.g., approximately -35 mV). Interestingly, the presence of serum caused the zeta potentials to become less negative (about -20 mV in OptiMEM and -10 mV in Li(2)SO(4)), even though serum contains negatively charged entities that have been demonstrated to lead to more negative zeta potentials in other lipoplex systems. The combined measurements of zeta potential and cryo-TEM are consistent with the proposition that DNA threads separate from the lipoplex in the presence of serum, resulting in a decrease in the net negative charge of the surface of the lipoplex.     

Aqueous amphiphilic drug (amitriptyline hydrochloride)-bile salt mixtures at different temperatures

The formation of mixed micelles built of 7,12-dioxolithocholic and the following hydrophobic bile acids was examined by conductometric method: cholic (C), deoxycholic (D), chenodeoxycholic (CD), 12-oxolithocholic (12-oxoL), 7-oxolithocholic (7-oxoL), ursodeoxycholic (UD) and hiodeoxycholic (HD). Interaction parameter (β) in the studied binary mixed micelles had negative value, suggesting synergism between micelle building units. Based on β value, the hydrophobic bile acids formed two groups: group I (C, D and CD) and group II (12-oxoL, 7-oxoL, UD and HD). Bile acids from group II had more negative β values than bile acids from group I. Also, bile acids from group II formed intermolecular hydrogen bonds in aggregates with both smaller (2) and higher (4) aggregation numbers, according to the analysis of their stereochemical (conformational) structures and possible structures of mixed micelles built of these bile acids and 7,12-dioxolithocholic acid. Haemolytic potential and partition coefficient of nitrazepam were higher in mixed micelles built of the more hydrophobic bile acids (C, D, CD) and 7,12-dioxolithocholic acid than in micelles built only of 7,12-dioxolithocholic acid. On the other hand, these mixed micelles still had lower values of haemolytic potential than micelles built of C, D or CD. The mixed micelles that included bile acids: 12-oxoL, 7-oxoL, UD or HD did not significantly differ from the micelles of 7,12-dioxolithocholic acid, observing the values of their haemolytic potential.