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Metal ions and other elements play many different critical roles in all biological processes. They can be especially important in high concentrations for the functioning of organisms living in seawater. It is important to understand how much the concentrations of different trace elements in such organisms can be higher than in seawater. Some marine organisms capable of rapid recovery after different injuries are fascinating in this regard. Sea cucumbers Eupentacta fraudatrix can completely restore all organs and the whole body within several weeks after their division into two parts. Here, for the first time, a comparison of the content of different elements in seawater, sea cucumber, and its very stable multiprotein complex (2000 kDa) was performed using two-jet plasma atomic emission spectrometry. Among the 18 elements we found in sea cucumbers, seawater contained only six elements in detectable amounts, and their content decreased in the following order: Mg > Ca > B > Sr ≈ Si > Cr (0.13–930 µg/g of seawater). The content of these elements in sea cucumbers was higher compared with seawater (-fold): Ca (714) > Sr (459) > Cr (75) > Si (42)> B (12) > Mg (6.9). Only four of them had a higher concentration in the protein complex than in seawater (-fold): Si (120.0) > Cr (31.5) > Ca (9.1) > Sr (8.8). The contents of Mg and B were lower in the protein complex than in seawater. The content of elements additionally found in sea cucumbers decreased in the order (µg/g of powder) of P (1100) > Fe (47) > Mn (26) > Ba (15) > Zn (13) > Al (9.3) > Mo (2.8) > Cu (1.4) > Cd (0.3), and in the protein complex, in the order of P (290) > Zn (51) > Fe (23) > Al (14) ≈ Ni (13) > Cu (7.5) > Ba (2.5) ≈ Co (2.0) ≈ Mn (1.6) > Cd (0.7) >Ag (0.2). Thus, sea cucumbers accumulate various elements, including those contained in very low concentrations in seawater. The possible biological roles of these elements are discussed here.

Blend membranes were prepared by incorporating two types of polyethylene glycol (PEG) (molecular masses of 400 and 1000 g mol −1 ) into three grades of poly(ether- block -amide) (PEBAX), namely PEBAX 1074, PEBAX 1657, and PEBAX 2533. The PEGs, which were used as blending agents, were employed at mass fractions ranging from 10 to 40 wt.% based on the mass of PEBAX. The gas separation performance of each neat or blend membrane, comprising its CO 2 and CH 4 permeabilities and its ideal CO 2 /CH 4 selectivity, was studied at room temperature (25 °C) and at pressures of 2–8 bar. X-ray diffraction (XRD) and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) analyses were used to determine the crystallinities of and the chemical bonds in the prepared membranes, respectively. Scanning electron microscopy (SEM) was also utilized to observe the morphologies of the membranes. The results obtained from experimental investigations showed that the incorporation of low molecular mass PEG significantly increased the permeability but only slightly affected the ideal CO 2 /CH 4 selectivity, while the incorporation of high molecular mass PEG decreased the permeability considerably but sharply increased the ideal CO 2 /CH 4 selectivity. This behavior intensified as the polyether content of the PEBAX was decreased. Graphical abstract

The exogenous application of ethylene or 1-aminocyclopropane-1-carboxylic acid (ACC), the biosynthetic precursor for ethylene, to plants decreases the capacity of the cell wall to extend, thereby inhibiting stem elongation. In this study, the mechanism by which the extensibility of cell walls decreases in ACC-treated azuki bean epicotyls was studied. ACC decreased the total extensibility of cell walls, and such a decrease was due to the decrease in irreversible extensibility. ACC increased the molecular mass of xyloglucans but decreased the activity of xyloglucan-degrading enzymes. The expression of VaXTHS4, which only exhibits hydrolase activity toward xyloglucans, was downregulated by ACC treatment, whereas that of VaXTH1 or VaXTH2, which exhibits only transglucosylase activity toward xyloglucans, was not affected by ACC treatment. The suppression of xyloglucan-degrading activity by downregulating VaXTHS4 expression may be responsible for the increase in the molecular mass of xyloglucan. Our results suggest that the modification of xyloglucan metabolism is necessary to decrease cell wall extensibility, thereby inhibiting the elongation growth of epicotyls in ACC-treated azuki bean seedlings.

Capillary electrophoresis (CE) is a versatile analytical separation method in the field of biochemistry. Although it has been proved that the relative molecular mass (Mr) of the polymers determines the threshold concentration of the entangled polymer solution, which will affect the separation performance of DNA molecules, there is still no report on the effect of Mr on the separation performance of proteins. Herein, we have thoroughly performed the CE of proteins ranged from 14.3 kDa to 116 kDa in a mixed hydroxyethyl cellulose (HEC) solution. The mixed solution was obtained with various Mr including 90,000, 250,000, 720,000, and 1,300,000. Then, we found that the mixed polymer provided a high resolution for small protein molecules while increasing the efficiency of large ones. Results demonstrated that the migration time decreased if HEC (1,300,000) was mixed with the lower Mr one, and the mixed solution (1,300,000/250,000) offered the highest resolution. The resolution was negatively correlated with the electric field strength. Finally, we have employed the optimal electrophoretic conditions to separate proteins in human tears, and it showed that lysozyme, lipocalin, and lactoferrin from human tears were successfully resolved in the mixed HEC. Such work indicates that CE has the potential to be developed as a tool for the diagnosis of xerophthalmia, meibomian gland dysfunction, or other eye diseases.

The use of size-exclusion chromatography in combination with multi-angle laser-light scattering analysis (SEC–MALLS) can provide useful information pertaining to the molecular mass parameters of wood celluloses and hemicelluloses. When wood holocelluloses containing significant amounts of hemicelluloses were soaked in ethylenediamine (EDA) and subjected to sequential EDA-removal and solvent-exchange processes into 1,3-dimethyl-2-imidazolidinone (DMI) under suitable conditions, the resulting materials provided much more reliable molecular mass parameters when they were dissolved in LiCl/DMI and subjecting to SEC–MALLS analysis. Furthermore, the residual EDA molecules trapped in the EDA-treated holocelluloses could be removed by simply washing with methanol following the solvent-exchange process. The effect of the stirring time for the EDA-treated and solvent-exchanged eucalyptus holocellulose in 8 % (w/v) LiCl/DMI was investigated in terms of its impact on the molecular mass parameters of the high-molecular-mass cellulose fractions and found to have no impact for up to 5 months. The optimal EDA treatment and solvent-exchange conditions obtained for eucalyptus holocellulose were subsequently applied to various other wood holocelluloses, including Japanese cedar, ginkgo and birch, which gave characteristic SEC elution patterns together with the corresponding molecular mass parameters, depending on their hemicellulose contents and the number of cellulose/lignin/hemicellulose chemical linkages present in their high-molecular-mass cellulose fractions. The weight-average degrees of polymerization of the high-molecular-mass cellulose fractions in the wood holocelluloses ranged from 4400 to 6400, which were higher than those of cotton cellulose (2700) and bacterial cellulose (3100).

Hyaluronan is a simple repeating disaccharide polymer, synthesized at the cell surface by integral membrane synthases. The repeating sequence is perfectly homogeneous, and is the same in all vertebrate tissues and fluids. The polymer molecular mass is more variable. Most commonly, hyaluronan is synthesized as a high-molecular mass polymer, with an average molecular mass of approximately 1000-8000 kDa. There are a number of studies showing increased hyaluronan content, but reduced average molecular mass with a broader range of sizes present, in tissues or fluids when inflammatory or tissue-remodeling processes occur. In parallel studies, exogenous hyaluronan fragments of low-molecular mass (generally, <200 kDa) have been shown to affect cell behavior through binding to receptor proteins such as CD44 and RHAMM (gene name HMMR), and to signal either directly or indirectly through toll-like receptors. These data suggest that receptor sensitivity to hyaluronan size provides a biosensor of the state of the microenvironment surrounding the cell. Sensitive methods for isolation and characterization of hyaluronan and its fragments have been developed and continue to improve. This review provides an overview of the methods and our current state of knowledge of hyaluronan content and size distribution in biological fluids and tissues.

Fucoidans are marine sulfated biopolysaccharides that have heterogenous and complicated chemical structures. Various sugar monomers, glycosidic linkages, molecular masses, branching sites, and sulfate ester pattern and content are involved within their backbones. Additionally, sources, downstream processes, and geographical and seasonal factors show potential effects on fucoidan structural characteristics. These characteristics are documented to be highly related to fucoidan potential activities. Therefore, numerous chemical qualitative and quantitative determinations and structural elucidation methods are conducted to characterize fucoidans regarding their physicochemical and chemical features. Characterization of fucoidan polymers is considered a bottleneck for further biological and industrial applications. Consequently, the obtained results may be related to different activities, which could be improved afterward by further functional modifications. The current article highlights the different spectrometric and nonspectrometric methods applied for the characterization of native fucoidans, including degree of purity, sugar monomeric composition, sulfation pattern and content, molecular mass, and glycosidic linkages.

Dried blood spot (DBS) technique has become a new popular topic in anti-doping field in recent years due to its advantages of sample stability and easy operation. It can be employed as a supplementary method to routine urine analysis. However, the small volume of DBS samples (usually 10–20 μL) significantly reduces the application value of this technique. Therefore, the development of sensitive detection methods for the analysis of prohibited substances in DBS is particularly important. In this study, based on the characteristics of low molecular mass peptide (LMMP) drugs, systematic optimization strategies were utilized for the first time to establish a sensitive detection method for LMMPs in DBS. Without using DMSO to enhance mass spectrometry ionization efficiency of peptides, the limits of detection (LOD) ranged between 0.05 and 3.74 ng/mL, significantly better than the previously reported method (0.5–20 ng/mL). This method was validated according to the guidelines of the World Anti-Doping Agency (WADA), and corresponding post-administration study was conducted, demonstrating that the method could be applied to routine analysis of LMMP drugs in DBS. Moreover, since DMSO is not involved, this method also has the potential to simultaneously detect both LMMP and small molecular drugs.

Although sugar beets are primarily treated as a source of sucrose, due to their rich chemical composition, they can also be a source of other carbohydrates, e.g., mono- and oligosaccharides. The study focused on both fresh beet roots and those stored in mounds. Our studies have shown that, in addition to sucrose, sugar beet tissue also comprises other carbohydrates: kestose (3.39%) and galactose (0.65%) and, in smaller amounts, glucose, trehalose and raffinose. The acidic hydrolysis of the watery carbohydrates extracts resulted in obtaining significant amounts of glucose (8.37%) and arabinose (3.11%) as well as xylose and galactose and, in smaller amounts, mannose. An HPSEC liquid chromatography study of the molecular mass profile of the carbohydrate compounds present in the beet roots showed alongside the highest percentage (96.53–97.43%) of sucrose (0.34 kDa) the presence of pectin compounds from the araban group and arabinoxylooligosaccharides (5–9 kDa) with a percentage share of 0.61 to 1.87%. On the basis of our research, beet roots can be considered a potential source of carbohydrates, such as kestose, which is classified as fructooligosaccharide (FOS). The results of this study may be helpful in evaluating sugar beets as a direct source of various carbohydrates, or as a raw material for the biosynthesis of fructooligosaccharides (FOS) or galactooligosaccharides (GOS).

Pollen collected by pollinators can be used as a marker of the foraging behavior as well as indicate the botanical species present in each environment. Pollen intake is essential for pollinators’ health and survival. During the foraging activity, some pollinators, such as honeybees, manipulate the collected pollen mixing it with salivary secretions and nectar (corbicular pollen) changing the pollen chemical profile. Different tools have been developed for the identification of the botanical origin of pollen, based on microscopy, spectrometry, or molecular markers. However, up to date, corbicular pollen has never been investigated. In our work, corbicular pollen from 5 regions with different climate conditions was collected during spring. Pollens were identified with microscopy-based techniques, and then analyzed in MALDI-MS. Four different chemical extraction solutions and two physical disruption methods were tested to achieve a MALDI-MS effective protocol. The best performance was obtained using a sonication disruption method after extraction with acetic acid or trifluoroacetic acid. Therefore, we propose a new rapid and reliable methodology for the identification of the botanical origin of the corbicular pollens using MALDI-MS. This new approach opens to a wide range of environmental studies spanning from plant biodiversity to ecosystem trophic interactions.