AppliedChem, Volume 3, Issue 3 (September 2023) – 6 articles

The aim of this paper was to evaluate the effect of two different matrices (e.g., starch base flour vs. protein base flour) on the ability of near-infrared (NIR) spectroscopy to classify binary mixtures of chickpea (protein), corn and tapioca (starch) flours. Binary mixtures were made by mixing different proportions of chickpea plus corn, chickpea plus tapioca, and corn plus tapioca flour. Spectra were collected using NIR spectroscopy and the data analyzed using techniques such as principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA). The results showed an effect of the matrix on the PLS-DA classification results, in both classification rates and PLS loadings. The different combinations of flours/mixtures showed changes in absorbance values around 4752 cm⁻¹ that are associated with starch and protein. Nevertheless, the use of NIR spectroscopic might provide a valuable initial screening and identification of the potential contamination of flours along the supply and value chains, enabling more costly methods to be used more productively on suspect samples. Full article

Cuticular hydrocarbon (CHC) profiling shows promise as a chemotaxonomic tool for identifying and discriminating between closely related insect species. However, there have been limited studies using CHC profiling to differentiate between weevil species (Coleoptera: Curculionidae). This proof-of-concept study investigated the use of CHC and volatile profiling to discriminate between five weevil species from three genera in the Gonipterini tribe. A total of 56 CHCs and 41 other volatile compounds were found across the five species, with 83 of the compounds being identified through their mass fragmentation patterns. The number of CHCs from each species ranged from 20 to 43, while the proportion of CHCs unique to each species varied between 0% and 19%. The most abundant CHCs were nonacosane, 7-methylheptacosane, heptacosane, and hexacosane. Principal component analysis of the centred log-ratio transformed data revealed broad differences in CHC profiles between the two Oxyops species, with Bryachus squamicollis demonstrating the greatest divergence from the other Gonipterini species. The results suggest that CHC analysis could be used to support established taxonomic methods, including morphological features and genetic sequencing results. Full article

In this study, a new type of highly efficient and recyclable magnetic-fluorine-containing polyether composite demulsifier (Fe₃O₄@G-F) was synthesized by the solvothermal method to solve the demulsification problem of oil–water emulsion. Fe₃O₄@G-F was successfully prepared by grafting fluorinated polyether onto Fe₃O₄ and graphene-oxide composites. Fe₃O₄@G-F was characterized using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Taking the self-made crude-oil emulsion as the experimental object, the demulsification mechanism of the demulsifier and the influence of external factors, such as the temperature and pH value, on the demulsification performance of the demulsifier are discussed. The results show that the demulsification efficiency of the Fe₃O₄@G-F emulsion can reach 91.38% within 30 min at a demulsifier dosage of 750 mg/L, pH of 6, and a demulsification temperature of 60 °C. In neutral and acidic environments, the demulsification rate of the demulsifier is more than 90%. In addition, Fe₃O₄@G-F has been proven to have good magnetic effects. Under the action of an external magnetic field, Fe₃O₄@G-F can be recycled and reused in a two-phase system four times, and the demulsification efficiency is higher than 70%. This magnetic nanoparticle demulsifier has broad application prospects for various industrial and environmental processes in an energy-saving manner. Full article

Living systems, whether healthy or diseased, must obey the laws of chemistry. The purpose of this review is to identify the interpretive limits of cellular biochemistry using, largely, the tools of physical chemistry. We illustrate this approach using two major concepts in cancer: carcinogenicity and cancer recurrences. Cells optimize the chemical performance of enzymes and pathways during cancer recurrences. Biology has been primarily concerned with the analysis of high affinity interactions, such as ligand–receptor interactions. Collective weak interactions (such as van der Waals forces) are also important in determining biosystem behaviors, although they are infrequently considered in biology. For example, activity coefficients determine the effective concentrations of biomolecules. The in vivo performance of enzymes also depends upon intracellular conditions such as high protein concentrations and multiple regulatory factors. Phase separations within membranes (two dimensions) and nucleoli (three dimensions) are a fundamental regulatory factor within cells, as phase separations can alter reactant concentrations, local dielectric constants, and other factors. Enzyme agglomeration also affects the performance of biochemical pathways. Although there are many examples of these phenomena, we focus on the key steps of cancer: carcinogenicity and the biochemical mechanism of cancer recurrences. We conjecture that oxidative damage to histones contributes to carcinogenicity, which is followed by nucleolar phase separations and subsequent DNA damage that, in turn, contributes to the redistribution of enzymes mediating metabolic changes in recurrent breast cancer. Full article

By investigating the hydrophobic properties and functional components including ethyl caproate (EC), caproic acid (CA), isoamyl acetate (IA), isoamyl alcohol (IAA), isovaleraldehyde (IVA), and procyanidin B2 (PB2) in beverages, one can incorporate them with 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) lipids to create cell-sized lipid vesicles. The aim of this study was to explore the correlation between the concentration of flavors or functional compounds and the size of the lipid vesicles. It was observed that EC, CA, IA, and IAA decreased the size of lipid vesicles. In contrast, IVA and PB2 increased their size. To comprehend this correlation, both the chemical structure of these compounds in relation to DOPC membranes and the fluidity of the membranes were considered. The size of the lipid vesicles was influenced by the molecular interactions between the compounds and DOPC. Those were caused by, in particular, the balance between hydrophobicity and hydrophilicity. Compounds with higher hydrophobicity tended to decrease the size of the lipid vesicles, whereas compounds with greater hydrophilicity had the opposite effect, leading to an increase in size. These findings suggest that the size of lipid vesicles can serve as a potential indicator for rapidly evaluating the concentration of these components in beverages. Full article

A promising carrier for the development of polymer systems with controlled release of biologically active compounds is the aminopolysaccharide chitosan. In the present work, we studied the possibility of using chitosan films as a matrix for the N⁶-benzyladenine (BA), which is the natural cytokinin widely used in tissue culture. The aim of this work was to develop biopolymer carriers containing phytohormones cytokinins that provide its controlled release. As a result of the work, a number of biopolymer carriers containing BA were obtained, and the kinetics of moisture absorption of the resulting complexes and the kinetics of their release of cytokinins were studied. It has been shown that the use of a polymer carrier based on chitosan is a convenient matrix for achieving a prolonged biological effect from cytokinins. The obtained results will make it possible to purposefully design materials with an optimal delivery rate of cytokinins for a biological object. Full article