Stable physically adsorbed coating of poly-vinyl alcohol for the separation of basic proteins

In aqueous capillary electrophoresis, the electroosmotic flow can be strongly suppressed by coating the inner surface of the capillary. In the present work hydrophilic coating of 4% polyvinyl alcohol (PVA) has been used for the analysis of basic proteins. The coating is simple and easy to obtain. The separation of ribonuclease and α-chymotrypsin has been uniquely done with other three basic proteins (lysozyme, cytochrome-c and trypsin) using a buffer 11.60 mM sodium acetate and 18.40 mM acetic acid at pH 4.5 in addition to positive power supply of 20 kV at 25°C. Detection was performed using UV detector at 230 nm. The proposed PVA coated capillary provides reproducible separation of five basic proteins within 10 min with RSD values for mobility bellow 1.4% (n = 6) for all the five basic proteins. The stability of coated capillary has been checked up to 40 runs. The viscosity measurement for 4% PVA have been studied and scanning electron microscope (SEM) images obtained to make it compatible with future micro-chip applications.     

A new application of Baylis–Hillman alcohols to a diastereoselective synthesis of 3-nitrothietanes

Three key reactions, the generation of a nucleophile, an thia-Michael addition and an intramolecular cyclisation, were used to achieve an efficient one-pot diastereoseletive synthesis of 3-nitrothietanes. Thus, Baylis–Hillman alcohols and their aldehydes were reacted with either O,O-diethyl hydrogen phosphorodithioate or O,O-diethyl hydrogen phosphorodithioate in combination with a task-specific ionic liquid [bmim]X–Y to afford the corresponding 2,3-di- or 2,3,4-trisubstituted thietanes, respectively. The reaction is high yielding and proceeds with complete diastereoselectivity in favour of the trans isomers.     

A facile and efficient carbocatalytic route to quaternary C-bearing N-tosylaziridines from Morita-Baylis-Hillman adduct in water

Graphene oxide (GO)/GO-I₂ co-catalyzed green synthesis of tosylaziridine bearing keto and nitrile/ester functional groups is reported. The strategy involves sequential GO-catalyzed oxidation of benzylic alcohol and GO-I₂ catalyzed nitrene insertion into olefin of Morita-Baylis-Hillman adduct. Operational simplicity, use of water as solvent, ambient reaction conditions, excellent yield of products (88–96%) and recyclability of catalyst up to five times without any substantial change in morphology as well as catalytic efficiency are the salient features of the envisaged protocol.     

Review on Recent Advances in Metal Ions Sensing Using Different Fluorescent Probes

Fluorescence probes serves as unique detection methods for its simplicity and low detection limit (LOD) and especially bioimaging ability. Research on the probes has already sprouted during the last decade with the help of its molecular recognition properties. This review spotlights recent progress in sensing and bioimaging biologically, environmentally and industrially important metal ions e.g. Zn²⁺, Cu²⁺, Hg²⁺, Ag⁺ etc. using suitable fluorescent chemosensors including carbon quantum dots (CQD).     

Caragana rosea Turcz Methanol Extract Inhibits Lipopolysaccharide-Induced Inflammatory Responses by Suppressing the TLR4/NF-κB/IRF3 Signaling Pathways

Caragana rosea Turcz, which belongs to the Leguminosae family, is a small shrub found in Northern and Eastern China that is known to possess anti-inflammatory properties and is used to treat fever, asthma, and cough. However, the underlying molecular mechanisms of its anti-inflammatory effects are unknown. Therefore, we used lipopolysaccharide (LPS) in RAW264.7 macrophages to investigate the molecular mechanisms that underlie the anti-inflammatory activities of a methanol extract of Caragana rosea (Cr-ME). We showed that Cr-ME reduced the production of nitric oxide (NO) and mRNA levels of iNOS, TNF-α, and IL-6 in a concentration-dependent manner. We also found that Cr-ME blocked MyD88- and TBK1-induced NF-κB and IRF3 promoter activity, suggesting that it affects multiple targets. Moreover, Cr-ME reduced the phosphorylation levels of IκBα, IKKα/β and IRF3 in a time-dependent manner and regulated the upstream NF-κB proteins Syk and Src, and the IRF3 protein TBK1. Upon overexpression of Src and TBK1, Cr-ME stimulation attenuated the phosphorylation of the NF-κB subunits p50 and p65 and IRF3 signaling. Together, our results suggest that the anti-inflammatory activity of Cr-ME occurs by inhibiting the NF-κB and IRF3 signaling pathways.     

Quantification and Isolation of Plumbagin (Plumbago zeylanica Linn.) by High-Performance Thin-Layer Chromatography

JPC – Journal of Planar Chromatography – Modern TLC - A simple, rapid, selective, and quantitative high-performance thinlayer chromatographic (HPTLC) method has been developed for the...     

Ionic liquid-promoted one-pot oxidative Michael addition of TMSCN to Baylis-Hillman adducts

The first example of ionic liquid-promoted one-pot oxidative conjugate hydrocyanation of Baylis-Hillman adducts with trimethylsilyl cyanide (TMSCN) is reported. The oxidation of Baylis-Hillman adducts with IBX/[bmim]Br or isomerization-oxidation with NaNO₃/[Hmim]HSO₄ systems affords β-ketomethylene compounds or [E]-cinnamaldehydes, respectively. These α,β-unsaturated carbonyl compounds undergo Michael addition with TMSCN in the same vessel to afford the corresponding thermodynamically more stable β-cyanated products. Thermodynamically less stable 1,2-addition products were not formed. The present regioselective reactions are promoted by ionic liquids, which can be recycled easily for further use without any loss of efficiency.     

Synthetic routes for phenazines: an overview

Phenazines are known to exhibit a diverse range of biological properties, such as antimicrobial, antitumor, antioxidant, antimalarial, neuroprotectant, etc. Owing to their significant applications in both medicinal and industrial fields, the phenazine framework has emerged as a remarkable synthetic target. The most general approaches for synthesis of phenazines include the Wohl–Aue method, Beirut method, condensation of 1,2-diaminobenzenes with 2C-units, reductive cyclization of diphenylamines, oxidative cyclization of 1,2-diaminobenzene/diphenylamines, Pd-catalyzed N-arylation, multicomponent approaches, etc. Advances in the exploitation of synthetic routes for assembly of this scaffold are reported in this review.     

Intra-Specific Chemotypic Variability of Forskolin Content in Coleus forskohlii (Wild.) Briq. Growing in Nilgiri Hills of India

JPC – Journal of Planar Chromatography – Modern TLC - Plant metabolite varies with season and geographic conditions. The present study is aimed at the identification of the potential...