Calcium-binding properties, stability, and osteogenic ability of phosphorylated soy peptide-calcium chelate.

Introduction: Bioactive peptides based on foodstuffs are of particular interest as carriers for calcium delivery due to their safety and high activity. The phosphorylated peptide has been shown to enhance calcium absorption and bone formation. Method: A novel complex of peptide phosphorylation modification derived from soybean protein was introduced, and the mechanism, stability, and osteogenic differentiation bioactivity of the peptide with or without calcium were studied. Result: The calcium-binding capacity of phosphorylated soy peptide (SPP) reached 50.24 ± 0.20 mg/g. The result of computer stimulation and vibration spectrum showed that SPP could chelate with calcium by the phosphoric acid group, carboxyl oxygen of C-terminal Glu, Asp, and Arg, and phosphoric acid group of Ser on the SPP at a stoichiometric ratio of 1:1, resulting in the formation of the complex of ligand and peptide. Thermal stability showed that chelation enhanced peptide stability compared with SPP alone. Additionally, in vitro results showed that SPP-Ca could facilitate osteogenic proliferation and differentiation ability. Discussion: SPP may function as a promising alternative to current therapeutic agents for bone loss.

The differences between the water- and alkaline-soluble Poria cocos polysaccharide: A review.

Poria cocos (PC) refers to a fungal species which is also known as "Fuling" in China. For >2000 years, PC has demonstrated its therapeutic values as a kind of traditional medicine. It is believed that the various biological benefits created by PCs highly rely on the Poria cocos polysaccharide (PCP). This review recapitulates the recent progress made in PCP in four aspects: i) the methods of extraction, separation, and purification, ii) structural characterization and identification, iii) the related bioactivities and mechanism of action, and iv) structure-activity relationships. Through discussion about the objective as mentioned above, it can be found out that PCP is categorized into water-soluble polysaccharide (WPCP) and alkaline-soluble polysaccharide (APCP), which are totally different in structure and bioactivity. The structures of WPCP are multiplicity whose backbone can be (1,6)-α-galactan and (1,3)-ß-mannoglucan etc. to perform various bioactivities including anti-tumor effect, anti-depressant effect, anti-Alzheimer effect, anti-atherosclerosis effect, hepatoprotection etc. The structures of APCP are much more single with backbone of (1,3)-ß-D-glucan and the studies of activity concentrate on anti-tumor effect, anti-inflammatory effect and immunomodulation. Besides, the future opportunities of WPCP are primary structure identification. For APCP, scholars can focus on the conformation of polysaccharide and its relationship with activity.

Polymyxin B-modified conjugated oligomer nanoparticle for targeted identification and enhanced photodynamic antimicrobial therapy.

We report a photosensitive polymyxin B-modified conjugated oligomer nanoparticle that integrates the targeted identification and synergistic photodynamic therapy in one treatment against resistant Gram-negative bacteria. The study expands the application of antibiotics and opens a new avenue for enhancing photodynamic antimicrobial therapy and fighting bacterial resistance.

An antioxidative galactomannan extracted from Chinese Sesbania cannabina enhances immune activation of macrophage cells.

In the present study, the antioxidant activities and immunostimulatory ability of a polysaccharide extracted from Chinese Sesbania cannabina, which was identified to be a galactomannan in our previous study, were investigated. The extracted polysaccharide exhibited strong DPPH, ABTS and hydroxyl radical scavenging activities and ferrous ion chelating activity in a concentration-dependent manner. The immune-enhancing effect of our polysaccharide on RAW 264.7 macrophage cells was investigated by determining the cell viability, phagocytic activity, NO and intracellular ROS production and mRNA expression of cytokines. The results indicated that the polysaccharide could increase the production of NO and intracellular ROS, as well as effectively trigger transcriptional activation of TLR-2/4, NF-κB, IL-10/1ß/6, IFN-γ, Ik-Bα, iNOS, COX-2 and TNF-α. These findings provide useful information for potential application of the polysaccharide extracted from Chinese Sesbania cannabina in the food industry.

Comparative proteomics analysis reveals the effect of germination and selenium enrichment on the quality of brown rice during storage.

Selenium (Se) can delay the quality deterioration of rice during storage, however, the mechanisms remain unclear. In this study, changes in the quality of brown rice, germinated brown rice, and selenized germinated brown rice stored at 38 °C and 90% relative humidity with various vacuum levels for 120 or 150 days were investigated. Fatty acid value and carbonyl value were determined every 30 days. Comparative proteomics technology was applied to determine the mechanisms of germination and Se enrichment on the storage quality of rice. Approximately 142 abundance changed proteins were found, of which 37 proteins were identified. By functional classification, proteins involved in processes of carbohydrate metabolism, lipid metabolism, oxidation-reduction, and protein catabolism may contribute to the different storage qualities of three samples. This study provides novel insights into Se response in rice at the proteome level, which are expected to be beneficial for exploring Se response tracts in rice.

Confinement of Iodine Molecules into Triple-Helical Chains within Robust Metal-Organic Frameworks.

During nuclear waste disposal process, radioactive iodine as a fission product can be released. The widespread implementation of sustainable nuclear energy thus requires the development of efficient iodine stores that have simultaneously high capacity, stability and more importantly, storage density (and hence minimized system volume). Here, we report high I2 adsorption in a series of robust porous metal-organic materials, MFM-300(M) (M = Al, Sc, Fe, In). MFM-300(Sc) exhibits fully reversible I2 uptake of 1.54 g g-1, and its structure remains completely unperturbed upon inclusion/removal of I2. Direct observation and quantification of the adsorption, binding domains and dynamics of guest I2 molecules within these hosts have been achieved using XPS, TGA-MS, high resolution synchrotron X-ray diffraction, pair distribution function analysis, Raman, terahertz and neutron spectroscopy, coupled with density functional theory modeling. These complementary techniques reveal a comprehensive understanding of the host-I2 and I2-I2 binding interactions at a molecular level. The initial binding site of I2 in MFM-300(Sc), I2I, is located near the bridging hydroxyl group of the [ScO4(OH)2] moiety [I2I···H-O = 2.263(9) Å] with an occupancy of 0.268. I2II is located interstitially between two phenyl rings of neighboring ligand molecules [I2II···phenyl ring = 3.378(9) and 4.228(5) Å]. I2II is 4.565(2) Å from the hydroxyl group with an occupancy of 0.208. Significantly, at high I2 loading an unprecedented self-aggregation of I2 molecules into triple-helical chains within the confined nanovoids has been observed at crystallographic resolution, leading to a highly efficient packing of I2 molecules with an exceptional I2 storage density of 3.08 g cm-3 in MFM-300(Sc).

Acetylcholinesterase inhibitory activity of Chinese sufu (fermented tofu) ethanol-extract.

Acetylcholinesterase (AChE) inhibitory activities of commercial sufu and self-produced sufu were investigated in this experiment. The anti-AChE activities of commercial sufu samples of 15 brands, sourcing from various parts of China, and self-produced sufu, fermented with Actinomucor elegans 3.118, were measured. The results indicated that ethanol extract of Chinese sufu exhibited significant inhibitory activity against AChE in vitro. The inhibitory activity of No. 5 sufu was the strongest (IC50, 0.191 mg/ml), while the pre-fermented sufu showed the highest inhibitory activity during sufu manufacturing. In addition, soybean extracts and potato extracts were used to culture A. elegans 3.118 in order to estimate which culture was preferable for the production of these AChE inhibitors. The soybean extracts, after fermentation by A. elegans 3.118, showed higher anti-AChE activity than did the potato extracts. The IC50 of the soybean extracts was 1.29 µg/ml.

Synergistic antimicrobial activities of natural essential oils with chitosan films.

The synergistic antimicrobial activities of three natural essential oils (i.e., clove bud oil, cinnamon oil, and star anise oil) with chitosan films were investigated. Cinnamon oil had the best antimicrobial activity among three oils against Escherichia coli , Staphylococcus aureus , Aspergillus oryzae , and Penicillium digitatum . The chitosan solution exhibited good inhibitory effects on the above bacteria except the fungi, whereas chitosan film had no remarkable antimicrobial activity. The cinnamon oil-chitosan film exhibited a synergetic effect by enhancing the antimicrobial activities of the oil, which might be related to the constant release of the oil. The cinnamon oil-chitosan film had also better antimicrobial activity than the clove bud oil-chitosan film. The results also showed that the compatibility of cinnamon oil with chitosan in film formation was better than that of the clove bud oil with chitosan. However, the incorporated oils modified the mechanical strengths, water vapor transmission rate, moisture content, and solubility of the chitosan film. Furthermore, chemical reaction took place between cinnamon oil and chitosan, whereas phase separation occurred between clove bud oil and chitosan.