Ganoderma lucidum polysaccharides exert anti-hyperglycemic effect on streptozotocin-induced diabetic rats through affecting β-cells

Previous studies have demonstrated that Ganoderma lucidum polysaccharides (Gl-PS) exhibited potential antihyperglycemic effect in rats. The aim of the present study was to investigate the mechanism of the hypoglycemic effect of a low- molecular-weight Gl-PS in streptozotocin (STZ)-induced diabetic Sprague-Dawley (SD) rats. Gl-PS was extracted and purified from Ganodema lucidum fruiting body. 50 male SD rats were included in the study; 10 were taken as healthy controls; 40 were induced to diabetes by a single injection of 65 mg/kg STZ, of which 30 were selected as successful diabetic rat models. The 30 diabetic rats were divided into three groups: Gl-PS (200 mg/kg Gl-PS), metformin (100 mg/kg metformin) and diabetic control (n = 10 per group). After eight weeks' oral administration, plasma concentrations of fasting glucose, triacylglyceride, total cholesterol and nitric oxide were significantly decreased in Gl-PS and metformin groups. Pancreatic superoxide dismutase, catalase and glutathione peroxidase were significantly increased in Gl-PS and metformin groups. Histopathological results showed that Gl-PS and metformin had protective effect on β-cells. The mRNA expressions of Bcl-2 and PDX-1 in pancreas were up-regulated, but Bax, iNOS and Casp-3 down-regulated in Gl- PS and metformin groups compared to diabetic control group. The present results suggested that Gl-PS had a hypoglycemic effect in STZ-induced diabetic rats through preventing apoptosis of pancreatic β-cells and enhancing β-cells regeneration.     

Modulation of the differentiation of dental pulp stem cells by different concentrations of β-glycerophosphate

Dentinogenesis is a necessary prerequisite for dental tissue engineering. One of the steps for dentinogenesis is to obtain large quantities of highly purified odontoblasts. Therefore, we have undertaken an experiment applying different concentrations of β-glycerophosphate (β-GP) to induce the differentiation of dental pulp stem cells (DPSCs) in a long-term 28-day culture. In the meanwhile, we have studied the time- and maturation-dependent expression of matrix extracellular phosphoglycoprotein (MEPE) and that of the odontoblast-like marker-dentin sialoprotein (DSP), in order to investigate an optimized mineralized condition. Western blot results revealed that the expression of DSP became lower when accompanied by the increase of the β-GP concentration, and there was also an influence on MEPE expression when different concentrations of β-GP were applied. Meanwhile, the mineralized groups had an inhibitory function on the expression of MEPE as compared with the control group. Above all, all experimental groups successfully generated mineralized nodules by Alizarin Red S and the 5 mM β-GP group formed more mineralized nodules quantitated using the CPC extraction method. In conclusion, there is a significant modulation of the β-GP during the differentiation of the DPSCs. The degree of odontoblast differentiation is β-glycerophosphate concentration dependent. A low concentration of β-GP (5 mM) has been shown to be the optimal concentration for stimulating the maturation of the DPSCs. Moreover, MEPE accompanied with DSP clearly demonstrates the degree of the differentiation.     

Role of autophagy in diabetes and endoplasmic reticulum stress of pancreatic β-cells

Type 2 diabetes mellitus is characterized by insulin resistance and failure of pancreatic β-cells producing insulin. Autophagy plays a crucial role in cellular homeostasis through degradation and recycling of organelles such as mitochondria or endoplasmic reticulum (ER). Here we discussed the role of β-cell autophagy in development of diabetes, based on our own studies using mice with β-cell-specific deletion of Atg7 (autophagy-related 7 ), an important autophagy gene, and studies by others. β-cell-specific Atg7-null mice showed reduction in β-cell mass and pancreatic insulin content. Insulin secretory function ex vivo was also impaired, which might be related to organelle dysfunction associated with autophagy deficiency. As a result, β-cell-specific Atg7-null mice showed hypoinsulinemia and hyperglycemia. However, diabetes never developed in those mice. Obesity and/or lipid are physiological ER stresses that can precipitate β-cell dysfunction. Our recent studies showed that β-cellspecific Atg7-null mice, when bred with ob/ob mice, indeed become diabetic. Thus, autophagy deficiency in β-cells could be a precipitating factor in the progression from obesity to diabetes due to inappropriate response to obesity-induced ER stress.     

Comparative pharmacokinetic study of six lignans in normal and diabetic rats after oral administration of Saururus chinensis extract by LC–MS/MS

Saururus chinensis (SC) possesses significant anti-diabetic activity and lignans were its major bioactive compounds. In this study, a rapid and sensitive ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) method was established for simultaneous quantification of six lignans, namely (-)-(7R,8R)-machilin D ( 1 ), verrucesin ( 2 ), rel-(7S,8S,7′R,8′R)-3,3′,4,4′,5,5′-hexamethoxy-7.O.7′,8.8′-lignan ( 3 ), manassantin A ( 4 ), manassantin B ( 5 ), and saucerneol F ( 6 ) in rat’s plasma. It was validated with acceptable linearity (r ≥ 0.9922), accuracy (80.42–95.17%), precision (RSD ≤ 12.08%), and extraction recovery (80.36–93.45%). The method was successfully applied to the comparative pharmacokinetic study of the six lignans in normal and diabetic rats after oral administration of SC extract. Results showed that the areas under the plasma concentration-time curve (AUC_{0 → t} and AUC_{0 → ∞}) of (-)-(7R,8R)-machilin D, rel-(7S,8S,7′R,8′R)-3,3′,4,4′,5,5′-hexamethoxy-7.O.7′,8.8′-lignan, manassantin B, and saucerneol F in diabetic rats were significantly increased, and the plasma clearance (CL) of (-)-(7R,8R)-machilin D in diabetic rats was significantly decreased. However, the AUC_{0 → t} and AUC_{0 → ∞} of verrucesin were significantly decreased, and its CL was significantly increased in diabetic rats compared with those in normal rats. These results indicated that there were remarkable differences in the pharmacokinetic parameters between the normal and diabetic rats. The pharmacokinetic studies might be beneficial for the clinical use of SC as hypoglycemic agent.     

Modulation of the aggregation behaviour and physicochemical properties of 1-dodecyl-3-methylimidazolium bromide in aqueous solutions by β-CD

The modulation of aggregation behaviour of ionic liquids (ILs) in aqueous media is one of the important research topics. In the present work, aggregation behaviour of 1-dodecyl-3-methylimidazolium bromide ([C₁₂mim]Br) modulated by beta-cyclodextrin (β-CD) has been investigated by using conductivity, volume, fluorescence, dynamic light scattering and transmission electron microscopy techniques. The results suggested that the addition of β-CD significantly affects the aggregation of [C₁₂mim]Br in aqueous solutions. For example, the apparent critical micelle concentration increases with the increase of β-CD concentration; the average micellar size reduced with the increasing concentration of β-CD, and the process for micelle formation of [C₁₂mim]Br in aqueous β-CD solution is driven by entropy at lower temperature, while driven by enthalpy at higher temperature. It is expected that findings in this study would shed light on the potential applications of IL in supramolecular chemistry.     

Alkylation of phenol by β-pinene in the presence of aluminum phenolate

The alkylation of phenol by β-pinene using Al(OPh)₃ as a catalyst was studied. It was found that the composition of the products depended on the ratio of starting materials. The principal products were chromane-type ethers with an equimolar ratio of starting materials and an excess of phenol. ortho-Alkylated phenol and an ether with a terpene substituent of bornyl structure were formed with a two-fold excess of β-pinene.     

Modulation of the Self-Assembly of π-Amphiphiles in Water from Enthalpy- to Entropy-Driven by Enwrapping Substituents

Depending on the connectivity of solubilizing oligoethylene glycol (OEG) side chains to the π-cores of amphiphilic naphthalene and perylene bisimide dyes, self-assembly in water occurs either upon heating or cooling. Herein, we show that this effect originates from differences in the enwrapping capability of the π-cores by the OEG chains. Rylene bisimides bearing phenyl substituents with three OEG chains attached directly to the hydrophobic π-cores are strongly sequestered by the OEG chains. These molecules self-assemble at elevated temperatures in an entropy-driven process according to temperature- and concentration-dependent UV/Vis spectroscopy and calorimetric dilution studies. In contrast, for rylene bisimides in which phenyl substituents with three OEG chains are attached via a methylene spacer, leading to much weaker sequestration, self-assembly originates upon cooling in an enthalpy-driven process. Our explanation for this controversial behavior is that the aggregation in the latter case is dictated by the release of “high energy water” from the hydrophobic π-surfaces as well as dispersion interactions between the π-scaffolds which drive the self-assembly in an enthalpically driven process. In contrast, for the former case we suggest that in addition to the conventional explanation of a dehydration of hydrogen-bonded water molecules from OEG units it is in particular the increase in conformational entropy of back-folded OEG side chains upon aggregation that provides the pronounced gain in entropy that drives the aggregation process. Thus, our studies revealed that a subtle change in the attachment of solubilizing substituents can switch the thermodynamic signature for the self-assembly of amphiphilic dyes in water from enthalpy- to entropy-driven.     

A novel UPLC–MS/MS method for simultaneous quantification of trigonelline, 4-hydroxyisoleucine,and diosgenin from Trigonella foenum-graecum extract: Application to pharmacokinetic study in healthy and type 2 diabetic rats

Trigonelline (TR), 4-hydroxyisoleucine (4-HI), and diosgenin (DG) are the main bioactives of the purified standardized extract of the popular plant Trigonella foenum-graecum L. (TFG), and it has been proven effective for the treatment of various diseases. However, to the best of our knowledge, no study has investigated the pharmacokinetic parameters of purified standardized T. foenum-graecum extract in normal and diabetic Wistar rats. The present study has developed and validated a rapid, reliable, and sensitive simultaneous ultra-performance liquid chromatography MS method to estimate these bioactives. The chromatographic separation was achieved using methanol, acetonitrile, and 0.1% formic acid with the ideal gradient flow system on a BEH Shield RP 18 column. A positive electrospray ionization mode was selected to estimate m/z values of TR (138.14 > 94.63), 4-HI (148.19 > 74.08), and DG (415.54 > 271.33). The method was robust and reproducible over the linearity range of 60–5000, 6–5000, and 15–5000 ng/mL for TR, 4-HI, and DG, respectively. Using this novel validated method, we investigated the pharmacokinetic parameters of bioactives using Phoenix WinNonlin version 8.0 (Certera) in normal and diabetic rats. The assay was successfully applied for the estimation of pharmacokinetic parameters using noncompartmental analysis. This investigation shows that the absorption rate increased, whereas distribution and elimination processes slowed down in diabetic rats compared with normal rats.     

Room temperature phosphorescence of α-bromonaphthalene induced by β-cyclodextrin in the presence of cyclohexane

β-Cyclodextrin (β-CD) can induce a-bromonaphthalene (BrN) to emit strong room temperature phosphorescence (RTP) in the presence of micro amounts of cyclohexane (c-hexane). Experiments of luminescence spectra, phosphorescence lifetime and fluorescence polarization prove the formation of c-hexane/β-CD/BrN ternary inclusion complex. The apparent formation constant of the ternary inclusion complex was determined and the effect mechanism of c-hexane on the RTP of BrN induced by β-CD is discussed.     

Application of synergistic β-lactamase inhibitors and antibiotics in the treatment of wounds infected by superbugs

Amoxicillin appears to be clinically drug-resistant due to the presence of β-lactamase in bacteria. Here, we designed and prepared a hollow Prussian Blue (HPB)-based therapeutic nanoplatform that was constructed by encapsulating amoxicillin into polyethyleneimine with β-lactamase inhibitor 4-carboxyphenylboronic acid (4-Cpba) decorated HPB nanoparticles (CPA NPs). The antibacterial effect of the CPA NPs on drug-resistant bacteria was observed by in vitro colony-forming unit, minimum inhibitory concentration, scanning electron microscopy, and fluorescence tests. The results show that amoxicillin effectively inhibited Escherichia coli and Staphylococcus aureus-resistant bacteria in the presence of 4-Cpba. The in vivo experimental results show that the CPA NPs exhibited a synergistic anti-infective effect in vivo, which inhibited the inflammatory response and apoptosis induced by the drug-resistant bacterial infection, and promoted wound healing in mice. The hematoxylin and eosin staining and blood biochemical experiments revealed that the acute toxicity of the material was negligible and it had good biocompatibility. Our results verify our design that CPA NPs can restore the antibacterial activity of amoxicillin.     

Effects of voriconazole and fluconazole on the pharmacokinetics of almonertinib in rats by UPLC–MS/MS

Almonertinib was included in the first-line treatment of non-small cell lung cancer with EGFR T790M mutations by the Chinese Society of Clinical Oncology in 2021. Considering that immunocompromised lung cancer patients are prone to opportunistic fungal infections, and most triazole antifungal drugs are moderate or strong inhibitors of CYP3A4, this study was conducted to develop and validate an accurate and rapid ultra-performance liquid chromatography tandem mass spectrometry method for quantifying almonertinib in plasma and for investigating the pharmacokinetic changes of almonertinib caused by voriconazole and fluconazole in rats. After liquid–liquid extraction with tert-butyl methyl ether, an XSelect HSS T3 column (2.1 × 100 mm, 2.5 μm, Waters) was used for the chromatographic separation of almonertinib and sorafenib-D₃ (internal standard). The analytes were detected using an AB Sciex Triple Quad 5,500 mass spectrometer in the positive ionization mode. The method exhibited great linearity (0.5–200 ng/ml, r > 0.997) and stability under the established experimental conditions. All validation experiments were in accordance with the guidelines, and the results were all within the acceptable limits. This method was successfully applied to the researches of pharmacokinetics and drug interactions for almonertinib in rats. Voriconazole and fluconazole significantly altered the pharmacokinetic profiles of almonertinib and increased the systemic exposure of almonertinib in rats to different degrees, but further human trials should be conducted to validate the results.     

Application of β-cyclodextrin for the analysis of estrogenic steroids in human urine by high-performance liquid chromatography

Summary A procedure is described for simultaneous determination of estriol, estrone and 17-estradiol in human urine. After acid hydrolysis of the sulphate conjugates, the estrogens were extracted into diethyl ether. The ether extracts were concentrated and applied directly to an HPLC column. Using a 25 cm C-18 column and acetonitrile-water modified by the addition of -cyclodextrin as mobile phase, the separation of estriol, estradiol and estrone was achieved within 20 minutes. The extraction of estrogens from the biological matrix is excellent. Estrogens were detected using a UV-detector (280 nm) or a spectrofluorimetric detector (_exc=280nm, _em=312 nm). The latter detection system has been used for the determination of estrogens in the urine of non-pregnant women. The procedure is simple and can be used in clinical practice.     

Diffusion of linear paraffins in silicalite studied by the ZLC method in the presence of CO2

The diffusion behavior of C₄–C₁₀ n-alkanes in silicalite-1 has been investigated by using the Zero Length Column method. The diffusivities derived from measurements at different purge rates with different purge gases confirming intracrystalline diffusion control. Data are compared with results reported in the literature for MFI zeolites. The diffusivities were found to be consistent and agree well with data previous obtained by ZLC. However, these data showed a remarkable disagreement with other reported techniques (PFG-NMR, QENS and Permeation). The eventual influence of carbon dioxide (CO₂) adsorption on diffusion properties of n-alkanes in silicalite was also investigated. For this purpose, a series of experiments was performed involving hydrocarbons mixed with CO₂. Data were obtained at 303 K and flow rates between 20 and 80 mL/min. The presence of CO₂ does not seem to influence the intracrystalline transport rate of the investigated light hydrocarbons (n-C₄ and n-C₆). On the other hand, the situation for n-C₈ and n-C₁₀ is more complex. The diffusivity values are higher compared to the previously reported values.     

Synthesis and Characterization of the β-BaB2O4 Phase Obtained by the Polymeric Precursor Method

A modified polymeric precursor method based on the Pechini process was used to synthesize -BaB₂O₄ (-BBO) crystalline phase. D-sorbitol (C₆H₁₄O₆) was used as a polymerizing agent to avoid the loss of boron during the samples' calcination and crystallization. The -BBO stoichiometric crystalline phase was only obtained when sorbitol was added to the solution. The results of Raman spectroscopy show that the amorphous phase is only completely eliminated when the samples are heat-treated at 750°C for 20 h. Thin films of -BBO phase displaying a preferred orientation were obtained when crystallized at 750°C for 2 h and deposited on sapphire substrate.     

Face selectivity in the reactions of 2,4-disubstituted adamantanes and their modification by inclusion in β-cyclodextrin solutions

Sodium borohydride reduction reactions on 4-X-adamantan-2-ones (where X=ethyleneketal 11, ethylenethioketal 12, and methylene 15) were studied, which gave Z-alcohols 16 and 17 (from en-face attack) as the predominant products for ketones 11 and 12, but gave 1:1 mixture of Z- and E-18 alcohols for ketone 15. The en/zu face selectivity of 15 in sodium borohydride reduction was enhanced to 32/68 in β-CD solution. Both 1,3-dipolar addition and dichlorocarbene addition reactions on 4-ethyleneketal-2-methyleneadamantane 13 underwent again predominant en-face attack to give products in an E/Z ratio of >99:1 and 92:8, respectively. The exceptional high zu-face selectivity on the dichlorocarbene addition reaction of 15 may be explained by a temporal complexation between the carbene and the C₄-oxo group. In the epoxidation reaction of 13 and 15 the zu-face attack products were favored despite their steric congestions suggesting that hydrogen bonding interaction between the peroxide reagent and the C₄-oxo or 4-ethyleneketal is involved.     

The Use of β-Cyclodextrin Inclusion Complexes for the Analysis of Bisphenol a Residues in Water by Spectrofluorimetry

Abstract

The application of β-cyclodextrin inclusion complexes to determine trace levels of bisphenol A (BPA) in aqueous solution by spectrofluorimetry was investigated. A 1:1 stoichiometry of the host-guest complex between β-CD and BPA, as well as the association constant was determined by using the changes in the fluorescence of BPA that occur when it is included in the hydrophobic cyclodextrin cavity. A simple and sensitive spectrofluorimetric method for the determination of BPA residues is presented; the applicable concentration range was 10.0 to 200.0 μgL^?1. The detection limit obtained was 0.5 μg.L^?1. The accuracy of the proposed method, was checked in the analysis of water samples from different sources previously spiked with different amounts of BPA.     

The role of the βAsp residue in copper(II) binding by modified peptides

The synthesis and binding abilities of peptides containing β-amino acids towards Cu(II) ions are presented. The peptides studied were: Ala-βAsp-Ser-Gly and Arg-Lys-βAsp-Val-Tyr. Potentiometric titrations were carried out to establish the stoichiometry of the resulting metal-ligand complexes. The copper(II) coordination mode of the complexes was investigated by performing detailed spectroscopic analyses (UV–Vis, CD) in strict correlation with potentiometric measurements. The results obtained on the β-peptides studied allowed the characterization of the influence of this structural modification on the coordination abilities of the peptides. Moreover, the role of the α-Asp position in the peptide chain was also described.     

Applicability of Enzyme Columns Prepared by Co-Immobilising β-Glucuronidase and Arylsulfatase by the Sol-Gel Method for Deconjugation of Glucuronides and Sulfates in Urine

The paper describes the applicability of enzyme columns prepared by co-immobilising -glucuronidase and arylsulfatase in the pores of a sol-gel glass for deconjugation of urinary conjugates. After dialysing the crude Helix pomatia -glucuronidase/arylsulfatase preparation against PBS buffer the enzymes were co-entrapped without further purification steps in the sol-gel glass and the manually ground glass was packed into small glass columns.Urine samples spiked with 0.02–2 mM 4-nitrophenyl--D-glucuronide, 4-nitrophenyl sulfate, 4-methylumbelliferyl--D-glucuronide or 4-methylumbelliferyl sulfate were applied to the columns. Cleavage rates were determined by analysing the hydrolysis products 4-nitrophenol or 4-methylumbelliferone by high performance liquid chromatography. Quantitative hydrolysis of the conjugates investigated was reproducibly achieved within 10 minutes. Entrapment of the enzymes lead to an increased stability in organic solvents and a small shift in the pH optimum of enzyme activity. The columns could be used more than 170 times without loss of enzyme activity.