First macrocyclic oxamide Cu(II)–Co(II) complex: synthesis,crystal structure and magnetic properties

A oxamido-bridged binuclear complex, [Cu(L)Co(bpy)₂](ClO₄)₂·0.5C₂H₅OH·H₂O has been synthesized, and structurally and magnetically characterized, where L = 1,4,8,11- tetraazacyclotradecanne-2,3-dione and bpy = 2,2^′-bipyridine. In the complex, the copper atom from the macrocyclic oxamido-copper(II) precursor in a square-planar and cobalt atoms in a distorted octahedral environment is bridged by the oxamidate group, Cu⋯Co separation of 5.359 Å. The metal–metal separations are consistent with the sequence of decrease of the ion radius of the metal ion. The magnetic properties of the complex have been investigated. The χ_MT versus T plots is typical of antiferromagnetically coupled Cu(II)–Co(II).     

Effect of a halophilic aromatic yeast together with Aspergillus oryzae in koji making on the volatile compounds and quality of soy sauce moromi

Koji making is an essential step in the production of high‐quality soy sauce. In this study, we inoculated koji with a halophilic aromatic yeast (Zygosaccharomyces rouxii) and Aspergillus oryzae and investigated the effects on the volatile compounds and quality of soy sauce moromi. Our results suggest that the optimal yeast inoculation was approximately 1.5 × 10⁶ yeast per gram of koji, and excessive yeast greatly decreased A. oryzae enzyme activity. In comparison with the control group, there were no significant changes in the concentrations of amino nitrogen, total titratable acids, total soluble nitrogen and reducing sugar by extending the fermentation time during the first fermentation month, whereas the concentration of glutamate in the yeast‐inoculated sample increased by 46.16% and the arginine concentration decreased by 61.07%. After the second fermentation month, 17, 38 and 38 volatile components were identified by GC–MS in C1, C2 and C5, respectively. Moreover, a large number of volatile components, such as 2‐Methoxy‐4‐vinylphenol, ethyl acetate and 1‐Octen‐3‐ol were found in C2 and C5. And the total contents of volatile compounds in C2 were obviously higher than C5. This work furthers our understanding of the traditional multistrain koji making and provides a new method for enhancing the quality and flavour of soy sauce.     

Comparative in vivo toxicity,organ biodistribution and immune response of pristine,carboxylated and PEGylated few-layer graphene sheets in Swiss albino mice: A three month study

We present a comprehensive 3 month report on the acute and chronic toxicity of intravenously administered (20 mg kg⁻¹) few-layer graphene (FLG) and, its carboxylated (FLG-COOH) and PEGylated (FLG-PEG) derivatives in Swiss albino mice. Whole-animal in vivo tracking studies revealed that irrespective of surface modifications, graphene predominantly accumulated in lungs over a period of 24 h. Histological assessment and ex vivo confocal Raman spectral mapping revealed highest uptake and retention in lung tissue, followed by spleen, liver and kidney, with no accumulation in brain, heart or testis. FLG and FLG-COOH accumulated within organs induced significant cellular and structural damages to lungs, liver, spleen, and kidney, ranging from mild congestion to necrosis, fibrosis and glomerular filtration dysfunction, without appreciable clearance. Serum biochemistry analysis revealed that both FLG and FLG-COOH induced elevated levels of hepatic and renal injury markers. Quantitative RT-PCR studies conducted on 23 critical inflammation and immune response markers showed major alterations in gene expression profile by FLG, FLG-COOH and FLG-PEG treated animals. FLG-PEG in spite of its persistance within liver and spleen tissue for 3 months, did not induce any noticeable toxicity or organ damage, and displayed significant changes in Raman spectra, indicative of their biodegradation potential.     

Simultaneous stone-milling and extraction enables efficient one-step extraction of hard plant materials

Extraction of plant materials is an essential practice in various fields using natural compounds. Nevertheless, it is challenging to perform complicated extraction efficiently and consistently on materials with hard-to-crush structures. This work presents a new method called simultaneous stone-milling and extraction (SME) to achieve one-step extraction of hard materials. SME under its optimal conditions was confirmed to produce high quality extracts from whole spice seeds (anise seeds, dill seeds, fennel seeds) and coarse-cut star anise. Compared to other extraction methods like maceration, heat-assisted extraction and ultrasound-assisted extraction, SME extracts contained comparable or higher concentrations of general (polyphenols, flavonoids, antioxidants) and specific (enzyme inhibitors) bioactive groups. Hence, SME with its one-step operation is expected to simplify the task of plant extraction and contribute to the advances in studies using plant-derived phytochemicals.     

Ratiometric Photoacoustic Molecular Imaging for Methylmercury Detection in Living Subjects

Photoacoustic molecular imaging is an emerging and promising diagnostic tool for heavy metal ions detection. Methylmercury (MeHg⁺) is one of the most potent neurotoxins, which damages the brain and nervous system of human beings through fish consumption. The development of a selective and sensitive method for MeHg⁺ detection is highly desirable. In this Communication, we develope a chemoselective photoacoustic sensor (LP‐hCy7) composed of the liposome (LP) and MeHg⁺‐responsive near‐infrared (NIR) cyanine dye (hCy7) for MeHg⁺ detection within living subjects, such as zebrafish and mouse. The as‐prepared LP‐hCy7 nanoprobe displays unique dual‐shift NIR absorbance peaks and produces a normalized turn‐on response after the reaction of MeHg⁺ and hCy7 through a mercury‐promoted cyclization reaction. The absorbance intensities of LP‐hCy7 nanoprobe at 690 and 860 nm are decreased and increased, respectively. The ratiometric photoacoustic signal (PA860/PA690) is noticeably increased in the presence of MeHg⁺. These findings not only provide a ratiometric photoacoustic molecular imaging probe for the detection of metal ions in vivo, but also provides a tool for spectroscopic photoacoustic molecular imaging.     

1,3,5‐Triazino Peptide Derivatives: Synthesis,Characterization, and Preliminary Antileishmanial Activity

A library of short di‐, tri‐, and tetra‐peptides with an s‐triazine moiety at the N terminus and either an amide or ethyl ester C terminus was prepared in solution and on the solid phase. The two remaining positions of the s‐triazine moiety were substituted with methoxy, morpholino, or piperidino groups. All the synthesized peptide derivatives were analyzed by HPLC and fully characterized by IR spectroscopy, ¹H and ¹³C NMR spectroscopy, elemental analysis, and mass spectrometry (MALDI TOF/TOF). A preliminary study of the antileishmanial activity of the 1,3,5‐triazinyl peptide derivatives revealed that four dipeptide amide derivatives showed higher antipromastigote or antiamastigote activity than the reference standard drug miltefosine with no significance acute toxicity.