The development of zinc-ion storage cathode materials for aqueous zinc-ion batteries (AZIBs) is a necessary step for the construction of large-scale electrochemical energy conversion and storage devices. Iron-doped alpha-manganese dioxide (α-MnO) nanocomposites were achieved in this study via pre-intercalation of Fe during the formation of α-MnO crystals. A polypyrrole (PPy) granular layer was fabricated on the surface of α-MnO using acid-catalyzed polymerization of pyrroles.
View Article and Find Full Text PDFBackground: Stevia has been proposed as a potential antidiabetic sweetener, mainly based on inconsistent results from stevioside or the plant extract, yet lacking relative experimental evidence from individual steviol glycosides (SGs) and their metabolites.
Results: The results systematically revealed that the typical SGs and their final metabolite (steviol) presented an antidiabetic effect on streptozotocin (STZ) diabetic mice in all assayed antidiabetic aspects. In general, the performance strength of the samples followed the sequence steviol > steviol glucosyl ester > steviolbioside > rubusoside > stevioside > rebaudioside A, which is opposite to their sweetness strength order, and generally in accordance with the glucosyl group numbers in their molecules.
Water-mediated fertilization is ubiquitous in early land plants. This ancestral mode of fertilization has, however, generally been considered to have been lost during the evolutionary history of terrestrial flowering plants. We investigated reproductive mechanisms in the subtropical ginger Cautleya gracilis (Zingiberaceae), which has two pollen conditions - granular and filiform masses - depending on external conditions.
View Article and Find Full Text PDFJ Colloid Interface Sci
July 2019
Hypothesis: The properties of conventional surfactants (c-surfactants) are generally accepted to be amphipathicity-dominated, but extended surfactants (e-surfactants) are additionally polypropylene oxide (PPO)-dependent; this additional property makes us wonder how an intramolecular PPO spacer would be "extended" at various interfaces and what is responsible for the excellent all-round properties of e-surfactants.
Experiments: A series of novel sodium medium alkyl chain PPO-b-PEO sulfates (2-ethylhexyl polypropylene oxide-block-polyethylene oxide sulfates, CPES) were designed, synthesized and structurally identified. Tensiometry was applied to estimate the surfactant shape at the air/water surface.
A series of novel anionic e-surfactants n-C P S was molecular designed and synthesized from long-chain fatty alcohols by polypropoxylation and sulfation followed by neutralization. Excellent all-round performance of extended surfactants (e-surfactants) interests us how a simple polypropylene oxide (PPO) spacer has great effects on properties. By a comparative study of conventional/ethoxylated/extended n-alkylsulfate surfactants, we were surprised to find that e-surfactants are in an obvious rugby shape at the air/water surface according to molecular surface area ( a), and it comes down to the intramolecular PPO spacer coiling and surface-induced collapse.
View Article and Find Full Text PDFSteviol glycosides, a natural sweetener, may perform bioactivities via steviol, their main metabolite in human digestion. The metabolising kinetics, i.e.
View Article and Find Full Text PDFPolysaccharides from Ganoderma lucidum (GLPs) have been taken as effective supplements by both healthy people and cancer patients for many years. However, this short survey indicates that instead of inhibiting cancer cell growth, both submerge-cultured intracellular GLP and fruiting body GLP can stimulate the growth of human carcinoma cell lines lacking functional p53, such as HCT-116 p53(-/-), Saos-2, H1299, HL-60, MDA-MB-157. Conversely, the two GLPs inhibit all other assayed cells with functional p53.
View Article and Find Full Text PDFA β-galactosidase from Kluyveromyces lactis was found to specifically catalyze hydrolysis of the glycosyl ester linkage of stevioside to yield steviolbioside, a rare sweetener that also exists in Stevia rebaudiana leaves. In a packed bed reactor, a reaction coupling separation was realized and a production yield of steviolbioside reached 90% in 6 h. The hydrolysis product steviolbioside presented higher cytoxicity on human normal cells (hepatocytes cell L02 and intestinal epithelial cell T84) than stevioside did.
View Article and Find Full Text PDFInt J Clin Exp Pathol
June 2016
Excessive extracellular matrix degradation caused by the hyperfunction of matrix metalloproteinases (MMPs) has been implicated in the failure of pressure ulcers healing. EMMPRIN, as a widely expressed protein, has emerged as an important regulator of MMP activity. We hypothesize that EMMPRIN affects the process of pressure ulcer healing by modulating MMP activity.
View Article and Find Full Text PDFEnzymatic hydrolysis and transgalactosylation of stevioside (St) were investigated using a β-galactosidase from Sulfolobus sp. The hydrolysis yielded steviol as the main final product. Under the optimal transgalactosylation conditions, the highest conversion of stevioside was 87.
View Article and Find Full Text PDFSpecificity of glycosyl donors is a critical issue in transglycosylation of stevioside, the main methodology to improve edulcorant quality of stevioside. The most popular glucanotransferase applied in this reaction is cyclodextrin glucanotransferase (CGTase) that catalyses cyclisation, coupling, hydrolysis and disproportionation simultaneously; which results a crosstalk in the glycosyl donors that comes from initial reactants, reaction intermediates as well as side products in parallel reactions. In this work, the specificity of glycosyl donors was studied to understand the transglucosylation pathways with the designed experiments and material balance analysis on the products using a commercial CGTase.
View Article and Find Full Text PDFMedicinal mushroom polysaccharides such as Ganoderma lucidum polysaccharides (GLPs) have been commonly hypothesized to suppress tumor cells proliferation through immune effects. To verify this hypothesis through investigating comprehensive miRNA expression in polysaccharide treated cancer cells, an anticancer mycelia GLP was employed to disclose miRNA differential expression of human hepatocarcinoma cells (HepG2), by using a miRNA microarray assay based on Sanger miR-Base Release 16. The experiment and the analysis result indicates that among the 61 differential expressed miRNAs (p ≤ 0.
View Article and Find Full Text PDFNovel ampelopsin glucosides (AMPLS-Gs) were enzymatically synthesized and purified using a Sephadex LH-20 column. Each structure of the purified AMPLS-Gs was determined by nuclear magnetic resonance, and the ionic product of AMPLS-G1 was observed at m/z 505 (C₂₁H₂₂O₁₃·Na)⁺ using matrix-assisted laser desorption ionization time-of-flight mass spectrometry. AMPLS-G1 was identified as ampelopsin-4'-O-α-D-glucopyranoside.
View Article and Find Full Text PDFThe antitumor activity of intracellular polysaccharides from submerged fermentation of Ganoderma lucidum was investigated focusing on the inhibition on human liver cancer cells. The polysaccharides inhibited human hepatocarcinoma cell HepG2 during earlier phase with lower dosage but obviously became less functional in later phase regardless of the dosage applied. However, apoptosis of the drugged HepG2 cells appeared in later incubation phase with high dosage, and the apoptosis could be enhanced by supplemental dose of the intracellular polysaccharides.
View Article and Find Full Text PDFAppl Biochem Biotechnol
March 2012
Microwave has nonthermal effects on enzymatic reactions, mainly caused by the polarities of the solvents and substrates. In this experiment, a model reaction with caprylic acid and butanol that was catalyzed by lipase from Mucor miehei in alkanes or arenes was employed to investigate the nonthermal effect in nonaqueous enzymatic esterification. With the comparison of the esterification carried by conventional heating and consecutive microwave irradiation, the positive nonthermal effect on the initial reaction rates was found substrate concentration-dependent and could be vanished ostensibly when the substrate concentration was over 2.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
February 2009
The authors studied the fluorescence change of immobilized lipase from Rhizomucor miehei in the microwave assisted enzymatic esterification of caprylic acid and butanol in organic medium by investigating the fluorescence spectra in solvent or aqueous buffer after incubating the lipase with the solvent, caprylic acid and butanol under microwave irradiation, respectively. A comparison was made with the conventional heated enzymatic esterification in the solvents. Both of the heating modes, the microwave irradiation and conventional heating, can enhance the fluorescence intensity without shifting the emission wavelength of the lipase.
View Article and Find Full Text PDFJ Integr Plant Biol
February 2009
Current understanding of the classical ABC model of floral development has provided a new set of characters to evaluate floral evolution. However, what is still lacking is a clear assessment of this genetic program across monocots. Here, to investigate the evolution of members of class A and B genes in monocots, we report the sequence characteristic and transcript expression of three new MADS-box genes in Alpinia oblongifolia Hayata.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
April 2009
In the title compound, C(8)H(13)N(2)O(2) (+)·Cl(-)·H(2)O, the methyl C atom of the ethyl group is slightly out of the imidazole plane, with an N-C(ring)-C-C torsion angle of -15.1 (2)°. In the crystal structure, there are strong inter-molecular hydrogen-bonding inter-actions between the solvent water mol-ecule, the free chloride anion and the organic cation, resulting in a two-dimensional supra-molecular network in the ab plane.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
December 2008
In the title compound, C(11)H(14)N(2)O(5), the nitro group is approximately coplanar with the benzene ring, making a dihedral angle of 4.26 (17)°. The dihedral angle between the methyl-carbamate group and the benzene ring is 72.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
August 2005
The interaction between bovine serum albumin (BSA) a nd umbelliferone, an active component of Chinese herbs, with or without metal ions was investigated using fluorescence spectroscopy (FS) and UV. The experimental results showed that the umbelliferone molecules inserted into the hydrophobic pockets of BSA and quenched the intrinsic fluorescence of BSA by forming umbelliferone-BSA complex. The mechanism of fluorescence quenching was confirmed combining by both static quenching and nonradiative energy transferring.
View Article and Find Full Text PDFThe effect of four metal ions Cu(2+), Ni(2+), Zn(2+) and Co(2+) on the interaction between bovine serum albumin (BSA) and berberine chloride (BC) extracted from a traditional Chinese Herb coptis chinensis franch, was investigated mainly by means of UV and fluorescence spectroscopy in this paper. The four metal ions make the quenching efficacy of BC to BSA higher than that in the absence of these metal ions because of the possible transition of BSA molecular conformation caused by metal ions. It was found that the quenching mechanism is a combination of static quenching with nonradiative energy transfer.
View Article and Find Full Text PDFSheng Wu Gong Cheng Xue Bao
November 2002
Sheng Wu Gong Cheng Xue Bao
January 2002
Enzymatic synthesis of monoglycerides by glycerolysis of oil and fats in microaqueous solvent-free media was investigated by using lipase from pseudomonus fluorescens (PFL). Initial eutectic point(IEP) was substituted for melt point of oil and fats in Critical Temperature Theory. By investigating the glycerolysis under different IEP, it is showed that there is a relationship between composition of the oils and the yield of monoglycerides: Y = -0.
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