A highly sensitive GC–MS method for simultaneous determination of anacardic acids in cashew (Anacardium occidentale) nut shell oil in the presence of other phenolic lipid derivatives

The commercial value of cashew nut shell liquid (CNSL) has become a cornerstone of the agrowaste industry. It is the by‐product of the cashew industry and has an 1/8 inch thickness of soft honeycomb structure. CNSL contains phenolic lipids with aliphatic chains such as anacardic acid, cardanol, cardol and methyl cardol, and their derivatives. The developed GC–MS method is rapid, accurate and selective using a selected derivatizing reagent, namely N‐methyl‐N‐(trimethylsilyl)‐trifluoroacetamide that was previously diluted 1:1% with anhydrous pyridine. The proposed GC–MS method was applied for the analysis of different CNSL samples. The results showed that all classes of CNSL compounds were detected. The four alkyl phenols were detected with their different alkyl sidechains without any interference. This method is also specified for the detection of fatty acids of saturated and unsaturated chains. Silylation did not cause any alteration in the chemical structure of CNSL compounds regardless of esterification action. Silylation is considered a safe derivatizing agent compatible with GC chromatography and specific for all volatile and nonvolatile polar and nonpolar CNSL compounds that could be detected in CNSL samples.     

Generation of carbohydrate-deficient transferrin by enzymatic deglycosylation of human transferrin

Carbohydrate-deficient transferrin (CDT) molecules are transferrin isoforms that lack one or both of the carbohydrate groups attached to a normal human transferrin molecule. CDT has been reported to be a sensitive and specific marker for diagnosing alcoholism. This report demonstrates the in vitro generation of CDT molecules that can potentially be used as the standard in measuring CDT concentrations. This was achieved by deglycosylation of human transferrin with the enzyme Endo-β-N-acetylglucosaminidase F₂ (Endo-F₂). The enzyme was immobilized on sepharose beads, which were packed into a column. The immobilization of the enzyme not only eliminated the Endo-F₂ contamination of CDT, but also rendered the enzyme suitable for repetitive use. In this manner, it was possible to obtain at least 200 mg of CDT over a period of more than 3 mo, without any noticeable decrease of enzyme activity, using only 3.0 μg of enzyme. This proved to be an efficient method for generating CDT.     

Generation and Control of Bipartite Entanglement in a Correlated Spontaneous-Emission Laser

Journal of Russian Laser Research - Bipartite quantum entanglement has numerous practical applications in quantum computation and communication. Here, we study the temporal evolution of bipartite...     

Insights into the Protective Effects of Thymoquinone against Toxicities Induced by Chemotherapeutic Agents

The drugs used to treat cancer not only kill fast-growing cancer cells, but also kill or slow the growth of healthy cells, causing systemic toxicities that lead to altered functioning of normal cells. Most chemotherapeutic agents have serious toxicities associated with their use, necessitating extreme caution and attention. There is a growing interest in herbal remedies because of their pharmacological activities, minimal side effects, and low cost. Thymoquinone, a major component of the volatile oil of Nigella sativa Linn, also known as black cumin or black seeds, is commonly used in Middle Eastern countries as a condiment. It is also utilized for medicinal purposes and possesses antidiabetic, anti-cancer, anti-inflammatory, hepatoprotective, anti-microbial, immunomodulatory, and antioxidant properties. This review attempts to compile the published literature demonstrating thymoquinone’s protective effect against chemotherapeutic drug-induced toxicities.     

Iridium(III) Sensitisers and Energy Upconversion: The Influence of Ligand Structure upon TTA-UC Performance

Six substituted ligands based upon 2-(naphthalen-1-yl)quinoline-4-carboxylate and 2-(naphthalen-2-yl)quinoline-4-carboxylate have been synthesised in two steps from a range of commercially available isatin derivatives. These species are shown to be effective cyclometallating ligands for Ir^III, yielding complexes of the form [Ir(C^N)₂(bipy)]PF₆ (where C^N=cyclometallating ligand; bipy=2,2′-bipyridine). X-ray crystallographic studies on three examples demonstrate that the complexes adopt a distorted octahedral geometry wherein a cis-C,C and trans-N,N coordination mode is observed. Intraligand torsional distortions are evident in all cases. The Ir^III complexes display photoluminescence in the red part of the visible region (668–693 nm), which is modestly tuneable through the ligand structure. The triplet lifetimes of the complexes are clearly influenced by the precise structure of the ligand in each case. Supporting computational (DFT) studies suggest that the differences in observed triplet lifetime are likely due to differing admixtures of ligand-centred versus MLCT character instilled by the facets of the ligand structure. Triplet–triplet annihilation upconversion (TTA-UC) measurements demonstrate that the complexes based upon the 1-naphthyl derived ligands are viable photosensitisers with upconversion quantum efficiencies of 1.6–6.7 %.     

Deep Red Emitting Heteroleptic Ir(III) Complexes that Incorporate Unsymmetrical 4-quinoline Carboxylic Acid Derived Ligands

Six disubstituted ligands based upon 2-(2′-pyridinyl/pyrazinyl)quinoline-4-carboxylic acids have been synthesised, solvent-free, in one step from a range of commercially available isatin derivatives. These species behave as ancillary chelating ligands for Ir(III) complexes of the form [Ir(C^N)₂(N^N)]PF₆ (where C^N=cyclometalating ligand; N^N=2-(2′-pyridinyl/pyrazinyl)quinoline-4-carboxylic acids). An X-ray crystallographic study on one complex shows a distorted octahedral geometry wherein a cis-C,C and trans-N,N coordination mode is observed for the cyclometalating ligands. DFT calculations predicted that variations in N^N ligand from 2,2′-bipyridine to L^{1 – 6} should localise the LUMO on to the Lⁿ ligand and that the complexes are predicted to display MLCT/LLCT character. All complexes displayed luminescence in the deep red part of the visible region (674–679 nm) and emit from triplet states, but with little apparent tuning as a function of L^{1 – 6} . Further time-resolved transient absorption spectroscopy supports the participation of these triplet states to the excited state character.