Effects of Auricularia auricula-judae (Bull.) Quél. polysaccharide acid hydrolysate on glucose metabolism in diabetic mice under oxidative stress.

BACKGROUND: Oxidative stress can lead to uncontrolled glucose metabolism and, thus, diabetes. Auricularia auricula-judae (Bull.) Quél. polysaccharides possess biological activities, such as antioxidant and hypoglycemic effects, but their mechanism of their acid hydrolysates on oxidative stress-injured glucose metabolism disorders is unclear. PURPOSE: Using diabetic mice, we investigated the effect of the acid hydrolysate of polysaccharides from Auricularia auricula-judae (Bull.) Quél. on improving diabetes. STUDY DESIGN AND METHODS: The structural information of sample polysaccharides was measured by high performance gel permeation chromatography, nuclear magnetic resolution, and high performance liquid chromatography. The diabetic model was established by intraperitoneal injection of streptozotocin. For eight consecutive weeks, the mice were orally administered sample polysaccharides (100, 200, and 300 mg/kg b.w. per day) for intervention. The improvement effect of the samples on diabetes was explored by detecting the changes in biochemical indicators in mice, and the underlying mechanism was studied by transcriptomic and metabolomic analysis. RESULTS: The results showed that acid hydrolysate of Auricularia auricula-judae (Bull.) Quél. polysaccharides consisted mainly of mannose, xylose, glucuronic acid, and glucose; its weight-averaged molecular weight was 6.3842 × 104 Dalton, its number average molecular weight was 2.9594 × 104 Dalton; and the molecule contained α-Glc(1→4)-, ß-Glc(1→3)-, and ß-Man(1→4)-linked glycosidic bonds. A total of 100 mg/kg b.w. per day sample was the best intervention concentration. After eight weeks of intervention, the sample polysaccharides significantly reduced dynamic blood glucose and serum lipids, enhanced antioxidant enzyme activities, promoted glucagon like peptide-1 and insulin secretion, improved insulin sensitivity and alleviated insulin resistance in diabetic mice. Transcriptomic and metabolomic analyses showed that sample polysaccharides was able to ameliorate disorders of glucose metabolism by modulating gene expression such as glucokinase; and modulate the state of oxidative stress in mice in vivo by regulating the glutathione metabolism pathway. CONCLUSION: Acid hydrolysate of Auricularia auricula-judae (Bull.) Quél. polysaccharides improved glucose metabolism disorders by slowing down the oxidative stress injury in mice, thereby alleviating diabetes. This study provided a basis for determining the underlying mechanism of the antidiabetic effect of Auricularia auricula-judae (Bull.) Quél. polysaccharides, which would significantly improve the deep development and application of these materials in diabetes control.

A Theoretical Investigation of Novel Sila- and Germa-Spirocyclic Imines and Their Relevance for Electron-Transporting Materials and Drug Discovery.

A new class of spirocyclic imines (SCIs) has been theoretically investigated by applying a variety of quantum chemical methods and basis sets. The uniqueness of these compounds is depicted by various peculiarities, e.g., the incidence of planar six-membered rings each with two imine groups (two π bonds) and the incorporation of the isosteres carbon, silicon, or germanium spiro centers. Additional peculiarities of these novel SCIs are mirrored by their three-dimensionality, the simultaneous occurrence of nucleophilic and electrophilic centers, and the cross-hyperconjugative (spiro-conjugation) interactions, which provoke charge mobility along the spirocyclic scaffold. Substitution of SCIs with strong electron-withdrawing substituents, like the cyano group or fluorine, enhances their docking capability and impacts their reactivity and charge mobility. To gain thorough knowledge about the molecular properties of these SCIs, their structures have been optimized and various quantum chemical concepts and models were applied, e.g., full NBO analysis and the frontier molecular orbitals (FMOs) theory (HOMO-LUMO energy gap) and the chemical reactivity descriptors derived from them. For the assessment of the charge density distribution along the SCI framework, additional complementary quantum chemical methods were used, e.g., molecular electrostatic potential (MESP) and Bader's QTAIM. Additionally, using the aromaticity index NICS (nuclear independent chemical shift) and other criteria, it could be shown that the investigated cross-hyperconjugated sila and germa SCIs are spiro-aromatics of the Heilbronner Craig-type Möbius aromaticity.

Insight into the medium-long-medium structured lipids made from Camellia oil: Composition-structure relationship.

Medium-long-medium (MLM) structured lipid (SL) as a new SL is a potential functional ingredient in food and nutraceutical products, but its composition-structure-physicochemical properties relationship has not been revealed in food industry. MLM type of medium-long chain triacylglycerol (MLCT) was synthesized from Camellia oil by combi-lipase; its physicochemical properties and composition-structure relationship were investigated in this research. The higher MLCT (67.24% ± 0.09) and MLM (52.71% ± 0.53) productivities were achieved after parameter optimization. The physicochemical characterization of SLs exhibited mild thermal property, intermediate Fourier transform infrared spectroscopy absorption intensity, and better crystal morphology. Joint characterizations identified that MLM and long-medium-long type SL were rich in 1,3-dioctanoyl-2-linoleoyl glyceride (CaLCa), 1,3-dioctanoyl-2-oleoyl glyceride (CaOCa), 1,3-dilinoleoyl-2-octanoyl glyceride (LCaL), and 1,3-dilinoleoyl-2-decanoyl glyceride (LCL) components, respectively. This is ascribed to the higher proportion of caprylic and linoleic acid in 1,3-specific enzyme. The 3D structural analysis further demonstrated that the CaLCa, CaOCa, LCaL, and LCL molecules had lower steric energy to form symmetrical structure at 1,3-position. This research provides a practical method to produce MLM-type SL from edible oils and fats in food industry.

[Structure-activity relationship of Lycium barbarum polysaccharides].

As a traditional Chinese herb and functional food, the fruits of Lycium barbarum has been widely used for thousands of years in China. L. barbarum polysaccharides(LBPs) are predominant active components, which have immunomodulatory, antioxidant, hypoglycemic, neuroprotective, anti-tumor, and prebiotic activities. The molecular weight, monosaccharide composition, glycosidic bond, branching degree, protein content, chemical modification, and spatial structure of LBPs are closely related to their biological activity. Based on the previous studies of this research team, this paper systematically combed and integrated the research progress of structure, function, and structure-activity relationship of LBPs. At the same time, some problems restricting the clarification of the structure-activity relationship of LBPs were considered and prospected, hoping to provide references for the high value utilization of LBPs and in-depth exploration of their health value.

[Research advance on structure and function of amides in Zanthoxylum plants].

Zanthoxylum belongs to the Rutaceae family, and there are 81 Zanthoxylum species and 36 varieties in China. Most of the Zanthoxylum plants are used as culinary spice. In recent years, scholars in China and abroad have carried out in-depth research on Zanthoxylum plants, and found that the peculiar numbing sensation of Zanthoxylum plants originates from amides. It is also determined that amides are an important material basis for exerting pharmacological effects, especially in anti-inflammatory analgesia, anesthesia and other aspects. In this paper, 123 amides in 26 Zanthoxylum plants and their pharmacological activity that have been reported were summarized, which provided scientific reference for the clinical application of Zanthoxylum plants and the research and development of new drugs, and also facilitated the sustainable development and utilization of Zanthoxylum plant resources.

The location of the chemical bond. Application of long covalent bond theory to the structure of silica.

Oxygen is the most abundant terrestrial element and is found in a variety of materials, but still wanting is a universal theory for the stability and structural organization it confers. Herein, a computational molecular orbital analysis elucidates the structure, stability, and cooperative bonding of α-quartz silica (SiO2). Despite geminal oxygen-oxygen distances of 2.61-2.64 Å, silica model complexes exhibit anomalously large O-O bond orders (Mulliken, Wiberg, Mayer) that increase with increasing cluster size-as the silicon-oxygen bond orders decrease. The average O-O bond order in bulk silica computes to 0.47 while that for Si-O computes to 0.64. Thereby, for each silicate tetrahedron, the six O-O bonds employ 52% (5.61 electrons) of the valence electrons, while the four Si-O bonds employ 48% (5.12 electrons), rendering the O-O bond the most abundant bond in the Earth's crust. The isodesmic deconstruction of silica clusters reveals cooperative O-O bonding with an O-O bond dissociation energy of 4.4 kcal/mol. These unorthodox, long covalent bonds are rationalized by an excess of O 2p-O 2p bonding versus anti-bonding interactions within the valence molecular orbitals of the SiO4 unit (48 vs. 24) and the Si6O6 ring (90 vs. 18). Within quartz silica, oxygen 2p orbitals contort and organize to avoid molecular orbital nodes, inducing the chirality of silica and resulting in Möbius aromatic Si6O6 rings, the most prevalent form of aromaticity on Earth. This long covalent bond theory (LCBT) relocates one-third of Earth's valence electrons and indicates that non-canonical O-O bonds play a subtle, but crucial role in the structure and stability of Earth's most abundant material.

Time-specific ultrasonic treatment of litchi thaumatin-like protein inhibits inflammatory response in RAW264.7 macrophages via NF-κB and MAPK transduction pathways.

The pro-inflammation activity of litchi thaumatin-like protein (LcTLP) led to be responsible for the occurrence of adverse reactions after excessive consumption of litchi. This study aimed to characterize the changes in the structure and inflammatory activity of LcTLP induced by ultrasound treatment. Significant molecular structure of LcTLP changes occured at 15 min ultrasound treatment, and then tended to recover with subsequent treatment. Secondary structure (α-helices decreased from 17.3% to 6.3%), tertiary structure (the maximum endogenous fluorescence intensity decreased), and microstructure (mean hydrodynamic diameter reduced from 4 µm to 50 nm) of the LcTLP treated for 15 min (LT15) were significantly affected, which led to the inflammatory epitope of LcTLP (domain II and V-cleft) unfolded. In vitro, LT15 had a significant anti-inflammatory response, which inhibited NO production and had the best effect at 50 ng/mL in RAW264.7 macrophages (73.24%). Moreover, proinflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) secretion and mRNA expression levels were also significantly lower compared with untreated LcTLP (p < 0.05). Western blot further confirmed that the expressions of IκB-α, p65, p38, ERK and JNK reduced markedly (p < 0.05), which indicated LT15 inhibited the inflammatory response through NF-κB and MAPK transduction pathways. Overall, it can be hypothesized that LT15 exposed to low frequency ultrasonic fields have a direct effect on the protein surface structure and thus on the entry of LT15 into cells, making 15-minute ultrasound treatment potentially useful in reducing the pro-inflammatory properties of litchi or related liquid products.

Photophysical Behavior of Self-Organizing Derivatives of 10- and 12-Vertex p-Carboranes, and their Bicyclo[2.2.2]octane and Benzene Analogues.

Four series of isostructural derivatives of 3-ring liquid crystalline derivatives containing p-carboranes (12-vertex A, and 10-vertex B), bicyclo[2.2.2]octane (C), or benzene (D) as the variable structural element were investigated for their mesogenic behavior and electronic interactions. Comparative studies demonstrated that the effectiveness of elements A-D in stabilization of the mesophase typically increases in the order: B

Structural and dynamical studies of CH-πbonded CH4-C6H6dimer by ultrafast intermolecular Coulombic decay.

The inner-valence ionization and fragmentation dynamics of CH4-C6H6dimer induced by 200 eV electron impact is studied utilizing a multi-particle coincidence momentum spectroscopy. The three-dimensional momentum vectors and kinetic energy release (KER) of the CH4++C6H6+ion pairs are obtained by coincident momentum measurement. Our analysis on the absolute cross sections indicates that the intermediate dication CH4+-C6H6+is preferentially produced by the removal of an inner-valence electron from CH4or C6H6and subsequent relaxation of ultrafast intermolecular Coulombic decay followed by two-body Coulomb explosion. Combining withab initiomolecular dynamics (AIMD) simulations, the real-time fragmentation dynamics including translational, vibrational and rotational motions are presented as a function of propagation time. The revealed fragmentation dynamics are expected to have a potential implication for crystal structure imaging with various radiation sources.

Research progress and future study on physicochemical, nutritional, and structural characteristics of canola and rapeseed feedstocks and co-products from bio-oil processing and nutrient modeling evaluation methods.

This article aims to review research progress and provide future study on physicochemical, nutritional, and molecular structural characteristics of canola and rapeseed feedstocks and co-products from bio-oil processing and nutrient modeling evaluation methods. The review includes Canola oil seed production, utilization and features; Rapeseed oil seed production and canola oil seed import in China; Bio-processing, co-products and conventional evaluation methods; Modeling methods for evaluation of truly absorbed protein supply from canola feedstock and co-products. The article provides our current research in feedstocks and co-products from bio-oil processing which include Characterization of chemical and nutrient profiles and ruminal degradation and intestinal digestion; Revealing intrinsic molecular structures and relationship between the molecular structure spectra features and nutrient supply from feedstocks and co-products using advanced vibrational molecular spectroscopy technique. The study focused on advanced vibrational molecular spectroscopy which can be used as a fast tool to study molecular structure features of feedstock and co-products from bio-oil processing. The article also provides future in depth study areas. This review provides an insight as how to use advanced vibrational molecular spectroscopy for in-depth analysis of the relationship between molecular structure spectral feature and nutrition delivery from canola feedstocks and co-products from bio-oil processing.

Structure-activity relationship of Lycium barbarum polysaccharides / 中国中药杂志

As a traditional Chinese herb and functional food, the fruits of Lycium barbarum has been widely used for thousands of years in China. L. barbarum polysaccharides(LBPs) are predominant active components, which have immunomodulatory, antioxidant, hypoglycemic, neuroprotective, anti-tumor, and prebiotic activities. The molecular weight, monosaccharide composition, glycosidic bond, branching degree, protein content, chemical modification, and spatial structure of LBPs are closely related to their biological activity. Based on the previous studies of this research team, this paper systematically combed and integrated the research progress of structure, function, and structure-activity relationship of LBPs. At the same time, some problems restricting the clarification of the structure-activity relationship of LBPs were considered and prospected, hoping to provide references for the high value utilization of LBPs and in-depth exploration of their health value.

Research advance on structure and function of amides in Zanthoxylum plants / 中国中药杂志

Zanthoxylum belongs to the Rutaceae family, and there are 81 Zanthoxylum species and 36 varieties in China. Most of the Zanthoxylum plants are used as culinary spice. In recent years, scholars in China and abroad have carried out in-depth research on Zanthoxylum plants, and found that the peculiar numbing sensation of Zanthoxylum plants originates from amides. It is also determined that amides are an important material basis for exerting pharmacological effects, especially in anti-inflammatory analgesia, anesthesia and other aspects. In this paper, 123 amides in 26 Zanthoxylum plants and their pharmacological activity that have been reported were summarized, which provided scientific reference for the clinical application of Zanthoxylum plants and the research and development of new drugs, and also facilitated the sustainable development and utilization of Zanthoxylum plant resources.

Skin microbiome considerations for long haul space flights.

Dysbiosis of the human skin microbiome has long been associated with changes to the pH of the skin, dermal immune function and chronic skin conditions. Dermatological issues have been noted as the most prevalent medical presentation in the microgravity environment of space. The change in gravitational forces has been implicated in human immuno-suppression, also impacted by changes in the gastrointestinal-skin axis and its impact on Vitamin D metabolism, altered microbial gene expression in resident flora (leading changes in biofilm formation) and increased virulence factors in potential pathogens. There are also other stressors to the skin microbiome unique to space travel, including increased exposure to radiation, prolonged periods of dry washing technique, air quality and changes in microbe replication and growth parameters. Optimal microbiome health leads to enhanced skin barrier manufacture and maintenance, along with improved skin immune function and healing. In a microgravity environment expected to be experienced during long space flights, disruptions to the skin microbiome, coupled with increased virulence of pathological viruses and bacteria has implications for holistic skin health, astronaut cognitive function and mental health, and is coupled with slowed rates of wound healing. Scenario management for holistic skin health and restoration of microbiome homeostasis on long space flights require consideration.

Current understanding and future perspectives on the extraction, structures, and regulation of muscle function of tea pigments.

With the aggravating aging of modern society, the sarcopenia-based aging syndrome poses a serious potential threat to the health of the elderly. Natural dietary supplements show great potential to reduce muscle wasting and enhance muscle performance. Tea has been widely recognized for its health-promoting effects. which contains active ingredients such as tea polyphenols, tea pigments, tea polysaccharides, theanine, caffeine, and vitamins. In different tea production processes, the oxidative condensation and microbial transformation of catechins and other natural substances from tea promotes the production of various tea pigments, including theaflavins (TFs), thearubigins (TRs), and theabrownins (TBs). Tea pigments have shown a positive effect on maintaining muscle health. Nevertheless, the relationship between tea pigments and skeletal muscle function has not been comprehensively elucidated. In addition, the numerous research on the extraction and purification of tea pigments is disordered with the limited recent progress due to the complexity of species and molecular structure. In this review, we sort out the strategies for the separation of tea pigments, and discuss the structures of tea pigments. On this basis, the regulation mechanisms of tea pigments on muscle functional were emphasized. This review highlights the current understanding on the extraction methods, molecular structures and regulation mechanisms of muscle function of tea pigments. Furthermore, main limitations and future perspectives are proposed to provide new insights into broadening theoretical research and industrial applications of tea pigments in the future.

The extraction and isolation methods of tea pigments are detailedly introduced.The structural research progress of tea pigments are summarized.The effects of tea pigments in the prevention of muscle diseases are introduced.The mechanism of tea pigments in enhancing skeletal muscle function are proposed.

Preparation of Highly Substituted Sulfated Alfalfa Polysaccharides and Evaluation of Their Biological Activity.

Alfalfa polysaccharides (AP) receive wide attention in the field of medicine, because of their anti-inflammatory property. However, AP has high molecular weight and poor water solubility, resulting in low biological activity. We wanted to obtain highly bioactive alfalfa polysaccharides for further research. Herein, we successfully synthesized highly substituted sulfated alfalfa polysaccharides (SAP) via the chlorosulfonic acid (CSA)-pyridine (Pyr) method, which was optimized using response surface methodology (RSM). Under the best reaction conditions, that is, the reaction temperature, time, and ratio of CSA to Pyr being 55 °C, 2.25 h, and 1.5:1, respectively, the maximum degree of substitution of SAP can reach up to 0.724. Fourier transform infrared spectroscopy also confirmed the existence of sulfonic acid groups on SAP. Despite the increased average molecular weight of SAP, its water solubility is improved, which is beneficial for its biological activity. Further in vitro results showed that SAP exhibited better antioxidant activity and antibacterial ability than AP. Besides, the former can efficiently enhance the viability of oxidatively stressed intestinal epithelial cells compared with the latter. Furthermore, SAP has the potential to inhibit obesity. It is concluded that sulfation modification could improve the antioxidant, antibacterial, bovine intestinal epithelial cells' proliferation-promoting, and the obesity inhibition abilities of AP. The improvement of AP biological activity may provide references for the utilization of plant extracts that have weaker biological activity.

Effect of Continuous and Discontinuous Microwave-Assisted Heating on Starch-Derived Dietary Fiber Production.

Dietary fiber can be obtained by dextrinization, which occurs while heating starch in the presence of acids. During dextrinization, depolymerization, transglycosylation, and repolymerization occur, leading to structural changes responsible for increasing resistance to starch enzymatic digestion. The conventional dextrinization time can be decreased by using microwave-assisted heating. The main objective of this study was to obtain dietary fiber from acidified potato starch using continuous and discontinuous microwave-assisted heating and to investigate the structure and physicochemical properties of the resulting dextrins. Dextrins were characterized by water solubility, dextrose equivalent, and color parameters (L* a* b*). Total dietary fiber content was measured according to the AOAC 2009.01 method. Structural and morphological changes were determined by means of SEM, XRD, DSC, and GC-MS analyses. Microwave-assisted dextrinization of potato starch led to light yellow to brownish products with increased solubility in water and diminished crystallinity and gelatinization enthalpy. Dextrinization products contained glycosidic linkages and branched residues not present in native starch, indicative of its conversion into dietary fiber. Thus, microwave-assisted heating can induce structural changes in potato starch, originating products with a high level of dietary fiber content.

[Lectins in Viscum:a progress review].

Viscum plants,the evergreen perennial parasitic shrubs or subshrubs,are mainly distributed in tropical and subtropical regions. There are about 70 Viscum species around the world,including 11 species and one variety in China. Mistletoe lectins are typeⅡ ribosome-inactivating proteins( RIPs) extracted from Viscum plants with anticancer and immunoregulatory activities. Many studies have focused on the mistletoe lectins isolated from V. album in Europe and V. album var. coloratum distributed in South Korea,respectively,and several preparations,such as Iscucin Ⓡ,were developed and clinically applied for cancer treatment. Although Viscum plants are widely distributed in China,only a few studies of mistletoe lectins have been reported. The recent progress of mistletoe lectins was reviewed from extraction,purification,quantitative/qualitative detection,molecular structure,pharmacological activities,toxicities,and clinical application,aiming at providing a reference for in-depth research and utilization of mistletoe lectins produced in China.

Structural and emulsion stabilizing properties of pectin rich extracts obtained from different botanical sources.

The presented research studied the emulsifying and emulsion stabilizing capacity of pectin samples isolated from different plant origin: apple, carrot, onion and tomato. The acid extracted pectin samples showed distinct structural properties. Specifically, apple pectin showed a high degree of methylesterification (78.41 ± 0.83%), carrot pectin had the lowest concentration of other co-eluted cell wall polymers, onion pectin displayed a bimodal molar mass distribution suggesting two polymer fractions with different molar mass and tomato pectin was characterized by a high protein content (16.48 ± 0.05%). The evaluation of the emulsifying and emulsion stabilizing potential of the pectin samples included investigating their ability to lower the interfacial tension next to a storage stability study of pectin stabilized o/w emulsions. Creaming behavior as well as the evolution of the oil droplet size were thoroughly examined during storage using multiple analytical techniques. Overall, smaller oil droplet sizes were obtained at pH 2.5 compared to pH 6.0 indicating better emulsifying capacity at lower pH. The lowest emulsion stability was observed in emulsions formulated with tomato pectin in which weak flocculation and relatively fast creaming affected emulsion stability. Onion pectin clearly showed the most promising emulsifying and emulsion stabilizing potential. At both pH conditions, emulsions stabilized by the onion pectin sample displayed highly stable oil droplet sizes during the whole storage period. The presence of the two polymer fractions in this sample can play an important role in the observed stability. In future work, it could be evaluated if both fractions contribute to emulsion stability in a synergistic way. In conclusion, this work showed that pectin samples extracted from different plant origin display diverse structural properties resulting in varying emulsifying and emulsion stabilizing potential. Polymer molar mass potentially plays a major role in the structure-function relation.

Lectins in Viscum:a progress review / 中国中药杂志

Viscum plants,the evergreen perennial parasitic shrubs or subshrubs,are mainly distributed in tropical and subtropical regions. There are about 70 Viscum species around the world,including 11 species and one variety in China. Mistletoe lectins are typeⅡ ribosome-inactivating proteins( RIPs) extracted from Viscum plants with anticancer and immunoregulatory activities. Many studies have focused on the mistletoe lectins isolated from V. album in Europe and V. album var. coloratum distributed in South Korea,respectively,and several preparations,such as Iscucin Ⓡ,were developed and clinically applied for cancer treatment. Although Viscum plants are widely distributed in China,only a few studies of mistletoe lectins have been reported. The recent progress of mistletoe lectins was reviewed from extraction,purification,quantitative/qualitative detection,molecular structure,pharmacological activities,toxicities,and clinical application,aiming at providing a reference for in-depth research and utilization of mistletoe lectins produced in China.

Insights into maize starch degradation by high pressure homogenization treatment from molecular structure aspect.

High-pressure homogenization (HPH) is a common physical method used for starch modification. In this study, starch molecular structure in terms of chain-length distribution (CLD) and molecular size is characterized to explore the structural variations during HPH and its internal relations. It is found that: 1) the molecular size is significantly reduced by HPH treatments and further gradually decreases with HPH pressure increasing; 2) HPH degrades the long amylose chains with degree of polymerization (DP) ~ 2000-20,000 into short- and intermediate-amylose chains with DP ~ 100-1000 and DP ~ 1000-2000; 3) by HPH treatment, the proportion of amylopectin chains with DP ~ 6-12 and DP ~ 12-24 decreases while that with DP ~ 24-36 and DP ~ 36-100 increases, whereas, the amylopectin CLDs between HPH treated starch samples are not significantly varied; and 4) by a subtraction analysis, the molecular size of HPH treated starches shows a strong correlation with the proportion of degraded long amylose chains, indicating these long amylose chains might play a critical role in maintaining the large molecular size of starch. This study provides a further understanding of molecular features from the individual chains assembling into a whole branched molecule.