A simple supramolecular complex of boronic acid-appended β-cyclodextrin and a fluorescent boronic acid-based probe with excellent selectivity for d-glucose in water

Various diboronic acid-based chemosensors for d-glucose have been developed for use in diabetes diagnostic systems. However, most of these chemosensors have limitations, such as poor water solubility, difficulties in synthesis, and inability to selectively detect d-glucose from among other saccharides. We report a simple chemosensor based on a supramolecular complex of fluorophenylboronic acid-appended β-cyclodextrin (FPB-βCyD) and an anthracene-based probe having a boronic acid moiety (1). Hydrophobic 1 is encapsulated in the cyclodextrin cavity of FPB-βCyD, making the supramolecular complex (1/FPB-βCyD) applicable in a water-rich solvent mixture (98% water). Interestingly, 1/FPB-βCyD showed a strong turn-on response to d-glucose with a 9.6-fold enhancement in fluorescence intensity, and no response to other saccharides. This study uncovers an innovative approach based on the supramolecular assembly of simple components for the development of a water-soluble d-glucose chemosensor with excellent selectivity.

A simple supramolecular complex of modified cyclodextrin with a boronic acid probe enabled the highly selective detection of d-glucose in water.     

Biochemical characterization and biocatalytic application of a novel d-tagatose 3-epimerase from Sinorhizobium sp.

Sinorhizobium sp. d-tagatose 3-epimerase (sDTE) catalyzes the conversion of d-tagatose to d-sorbose. It also recognizes d-fructose as a substrate for d-allulose production. The optimal temperature and pH of the purified sDTE was 50 °C and 8.0, respectively. Based on the sDTE homologous model, Glu154, Asp187, Gln213, and Glu248, form a hydrogen bond network with the active-site Mn²⁺ and constitute the catalytic tetrad. The amino acid residues around O-1, -2, and -3 atoms of the substrates (d-tagatose/d-fructose) are strictly conserved and thus likely regulate the catalytic reaction. However, the residues at O-4, -5, and -6, being responsible for the substrate-binding, are different. In particular, Arg65 and Met9 were found to form a unique interaction with O-4 of d-fructose and d-tagatose. The whole cells with recombinant sDTE showed a higher bioconversion rate of 42.5% in a fed-batch bioconversion using d-fructose as a substrate, corresponding to a production of 476 g L⁻¹d-allulose. These results suggest that sDTE is a potential industrial biocatalyst for the production of d-allulose in fed-batch mode.

Sinorhizobium sp. d-tagatose 3-epimerase (sDTE) catalyzes the conversion of d-tagatose to d-sorbose.     

Synthesis of BINOL–xylose-conjugates as “Turn-off” fluorescent receptors for Fe3+ and secondary recognition of cysteine by their complexes

A novel chiral fluorescence “turn-off” sensor was synthesised using the click reaction. The sensor was a BINOL–xylose derivative, modified at the 2-position and linked by 1,2,3-triazole. It was structurally characterized by ¹HNMR, ¹³CNMR, ESI-MS and IR analysis. The selectivity of R-β-d-2 in methanol solution has been studied. Among the 19 transition metal ions, alkaline metal ions and alkaline earth metal ions studied, R-β-d-2 had a selective fluorescence quenching reaction for Fe³⁺. The detection limit of R-β-d-2 for Fe³⁺ was 0.91 μmol L⁻¹. Complexation between R-β-d-2 and Fe³⁺ was investigated by ESI-MS and ¹HNMR. The stoichiometric ratio of R-β-d-2 was 1 : 1. In addition, the R-β-d-2–Fe³⁺ complex was titrated with 20 naturally occurring amino acids and Hcy with GSH. It was found that the complex R-β-d-2–Fe³⁺ had a secondary recognition effect on Cys by switching to fluorescence.

A fluorescence sensor of BINOL–xylose derivative was synthesized, which could only detect Fe³⁺ by 1 + 1 complex with high selectivity and sensitivity. The complex of the derivative with Fe³⁺ was found to perform secondary recognition of cysteine.     

Structural analysis and antioxidant activity of an arabinoxylan from Malvastrum coromandelianum L. (Garcke)

Malvastrum coromandelianum L. (Garcke) is extensively used in traditional medicinal systems to treat various ailments. In the present study, an alkali-soluble polysaccharide (MAP) was isolated from the leaves of M. coromandelianum in 1.15% (w/w) yield. MAP was composed of l-rhamnose, l-arabinose, d-xylose, d-glucose and d-galactose in a 1.00 : 6.04 : 19.88 : 1.07 : 3.03 molar ratio along with d-glucuronic acid (1.95). Methylation/linkage analysis revealed a backbone of →4)-β-d-Xylp(1→ (30.09 mol%) with a side chain of →3)-α-l-Araf(1→ (15.21 mol%) residues. The structure of MAP was elucidated by a combination of degradative and derivatization techniques, including hydrolysis, alditol acetate derivatization, methylation, GC-MS, partial hydrolysis, ESI-MS and NMR (1D, 2D) spectral analysis. Based on correlation analysis, MAP was found to be an arabinoxylan comprising a backbone of →4)-β-d-linked Xylp(1→ with branching at O-2 by a →3)-α-l-Araf(1→ and →3)-β-d-Xylp(1→ chain. MAP also exhibited ferric ion reducing activity, with a reducing power of 0.914 ± 0.01 (R² = 0.972) at 1 mg mL⁻¹ concentration, which showed dose-dependent behavior. MAP can be utilized as a potential antioxidant.

The structure of MAP was studied by degradative, derivatization and spectroscopic methods, and it was found to be an arabinoxylan comprising a backbone of →4)-β-d-linked Xylp(1→ with branching at O-2 by →3)-α-l-Araf(1→ and →3)-β-d-Xylp(1→ chains.     

Structural characterization,anti-inflammatory and glycosidase inhibitory activities of two new polysaccharides from the root of Pueraria lobata

Diabetes seriously endangers public health and brings a heavy economic burden to the country. Inflammation is one of the main inducing factors of type-2 diabetes (T2D) and may cause some complications of diabetes, such as diabetic encephalopathy and peripheral neuropathy. In-depth research and development of drugs to cure diabetes and complications are of great significance. Pueraria lobate is a medicinal herb used in several countries to treat many diseases. Here, two new polysaccharides (PLB-1-1 and PLB-1-2) were isolated and purified from the root of Pueraria lobata with molecular weights of 9.1 × 10³ Da and 3.8 × 10³ Da, respectively. The structure was evaluated by monosaccharide composition, GC-MS and NMR spectroscopy. It was determined that PLB-1-1 comprised →4)-α-d-Glcp-(1→, α-d-Glcp-(1→, →6)-β-d-Galp-(1→, →3)-α-l-Araf-(1→, →3,6)-β-d-Manp-(1→ and →4,6)-β-d-Manp-(1→, and PLB-1-2 consisted of →4)-α-d-Glcp-(1→, β-d-Glcp-(1→, →4,6)-β-d-Glcp-(1→, →3,6)-β-d-Manp-(1→ and α-l-Fucp-(1→. Furthermore, both PLB-1-1 and PLB-1-2 showed anti-inflammatory and inhibitory activities of α-glucosidase and α-amylase in vitro. Therefore, the new polysaccharides, i.e., PLB-1-1 and PLB-1-2, may be considered candidates for the treatment of diabetes and its related complications.

Through the extraction, isolation and purification of Pueraria lobata, we identified two new polysaccharides with molecular weights of 9.1 × 10³ Da and 3.8 × 10³ Da, and found that they have excellent anti-inflammatory and glycosidase inhibitory effects.     

Antiproliferative activity of new pentacyclic triterpene and a saponin from Gladiolus segetum Ker-Gawl corms supported by molecular docking study

A new triterpenoidal saponin identified as 3-O-[β-d-glucopyranosyl-(1 → 2)-β-d-glucopyranosyl-(1 → 4)-β-d-xylopyranosyl]-2β,3β,16α-trihydroxyolean-12-en-23,28-dioic acid-28-O-α-l-rhamnopyranosyl-(1 → 4)-α-l-rhamnopyranosyl-(1 → 2)-β-d-glucopyranosyl-(1 → 2)-α-l-arabinopyranoside 1 together with a new oleanane triterpene identified as 2β,3β,13α,22α-tetrahydroxy olean-23,28-dioic acid 2 and 6 known compounds (3–8) have been isolated from Gladiolus segetum Ker-Gawl corms. The structural elucidation of the isolated compounds was confirmed using different chemical and spectroscopic methods, including 1D and 2D NMR experiments as well as HR-ESI-MS. Moreover, the in vitro cytotoxic activity of the fractions and that of the isolated compounds 1–8 were investigated against five human cancer cell lines (PC-3, A-549, HePG-2, MCF-7 and HCT-116) using doxorubicin as a reference drug. The results showed that the saponin fraction exhibited potent in vitro cytotoxic activity against the five human cancer cell lines, whereas the maximum activity was exhibited against the PC-3 and A-549 cell lines with the IC₅₀ values of 1.13 and 1.98 μg mL⁻¹, respectively. In addition, compound 1 exhibited potent activity against A-549 and PC-3 with the IC₅₀ values of 2.41 μg mL⁻¹ and 3.45 μg mL⁻¹, respectively. Interestingly, compound 2 showed the maximum activity against PC-3 with an IC₅₀ of 2.01 μg mL⁻¹. These biological results were in harmony with that of the molecular modeling study, which showed that the cytotoxic activity of compound 2 might occur through the inhibition of the HER-2 enzyme.

A new triterpenoidal saponin 1, a new oleanane triterpene 2, and 6 known compounds (3–8) have been isolated from Gladiolus segetum Ker-Gawl corms.     

Synthesis of alginate–polycation capsules of different composition: characterization and their adsorption for [As(iii)] and [As(v)] from aqueous solutions

The uptake of arsenite [As(iii)] and arsenate [As(v)] by functionalized calcium alginate (Ca-Alg) beads from aqueous solutions was investigated. Ca-Alg beads were protonated with poly-l-lysine (PLL) or polyethyleneimine (PEI) using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide (EDC/NHS) or glutaraldehyde (GA) as crosslinking agents. Four types of protonated beads were prepared: Ca-Alg-EDC/NHS (PLL or PEI) and Ca-Alg-GA (PLL or PEI). Fourier transform infrared spectroscopy in total attenuated reflection mode (FTIR-ATR), analysis showed presence and increased intensity of bands corresponding to OH, NH, CH₂ and CH₃ groups in modifications with both polycations. In addition, thermogravimetric analysis and atomic force microscopy of all modified capsules showed an increase in thermal stability and uniformity of the capsules, respectively. Ca-Alg-EDC/NHS-PLL beads had the maximum adsorption capacity of [As(v)] (312.9 ± 4.7 μg g⁻¹ of the alginate) at pH 7.0 and 15 minute exposure, while Ca-Alg-EDC/NHS-PEI beads had the maximum adsorption capacity of [As(iii)] (1052.1 ± 4.6 μg g⁻¹ of alginate). However, all these EDC containing beads were degraded in the presence of citrate. Ca-Alg-GA-PEI beads removed 252.8 ± 9.7 μg of [As(v)] μg g⁻¹ of alginate and 524.7 ± 5.3 de [As(iii)] μg g⁻¹ of alginate, resulting the most stable capsules and suitable for As removal.

A simple protonation of alginate beads allows the absorption of arsenate and arsenite.     

A novel catalytic kinetic method for the determination of mercury(ii) in water samples

Mercury(ii) ions act as catalyst in the substitution of cyanide ion in hexacyanoruthenate(ii) by pyrazine (Pz) in an acidic medium. This property of Hg(ii) has been utilized for its determination in aqueous solutions. The progress of reaction was followed spectrophotometrically by measuring the increase in absorbance of the yellow colour product, [Ru(CN)₅Pz]³⁻ at 370 nm (λ_max, ε = 4.2 × 10³ M⁻¹ s⁻¹) under the optimized reaction conditions; 5.0 × 10⁻⁵ M [Ru(CN)₆⁴⁻], 7.5 × 10⁻⁴ M [Pz], pH 4.00 ± 0.02, ionic strength (I) = 0.05 M (KCl) and temp. 45.0 ± 0.1 °C. The proposed method is based on the fixed time procedure under optimum reaction conditions. The linear regression (calibration) equations between the absorbance at fixed times (t = 15, 20 and 25 min) and [Hg(ii)] were established in the range of 1.0 to 30.0 × 10⁻⁶ M. The detection limit was found to be 1.5 × 10⁻⁷ M of Hg(ii). The effect of various foreign ions on the proposed method was also studied and discussed. The method was applied for the determination of Hg(ii) in different wastewater samples. The present method is simple, rapid and sensitive for the determination of Hg(ii) in trace amount in the environmental samples.

Mercury(ii) ions act as catalyst in the substitution of cyanide ion in hexacyanoruthenate(ii) by pyrazine (Pz) in an acidic medium.     

Chiral fluorescence recognition of glutamine enantiomers by a modified Zr-based MOF based on solvent-assisted ligand incorporation

In this study, three types of chiral fluorescent zirconium-based metal–organic framework materials were synthesized using l-dibenzoyl tartaric acid as the chiral modifier by the solvent-assisted ligand incorporation method, which was the porous coordination network yellow material, denoted as PCN-128Y. PCN-128Y-1 and PCN-128Y-2 featured unique chiral selectivity for the Gln enantiomers amongst seven acids and the highly stable luminescence property, which were caused by the heterochiral interaction and aggregation-induced emission. Furthermore, a rapid fluorescence method for the chiral detection of glutamine (Gln) enantiomers was developed. The homochiral crystals of PCN-128Y-1 displayed enantiodiscrimination in the quenching by d-Gln such that the ratio of enantioselectivity was 2.0 in 30 seconds at pH 7.0, according to the Stern–Volmer quenching plots. The detection limits of d- and l-Gln were 6.6 × 10⁻⁴ mol L⁻¹ and 3.3 × 10⁻⁴ mol L⁻¹, respectively. Finally, both the maximum adsorption capacities of PCN-128Y-1 for the Gln enantiomers (Q_e(l-Gln) = 967 mg g⁻¹; Q_e(d-Gln) = 1607 mg g⁻¹) and the enantiomeric excess value (6.2%) manifested that PCN-128Y-1 had strong adsorption capacity for the Gln enantiomers and higher affinity for d-Gln.

A stable luminescent zirconium-based MOF PCN-128Y-1 was synthesized by the SALI method and applied as a specific chiral selective adsorbent and a chiral fluorescence sensor for the recognition and quantitative analysis of Gln enantiomers.     

Gum acacia-based silver nanoparticles as a highly selective and sensitive dual nanosensor for Hg(ii) and fluorescence turn-off sensor for S2− and malachite green detection

A facile and green method was adopted to synthesize highly selective gum acacia-mediated silver nanoparticles as dual sensor (fluorescence turn-on and colorimetric) for Hg(ii) and fluorescence turn-off sensor for S²⁻ and malachite green. The mechanism proposed for a dual response towards Hg(ii) is the redox reaction between Ag(0) and Hg(ii), resulting in the formation of Ag(i) and Hg(0) and electron transfer from gum acacia to Ag(i), which further leads to the formation of an Ag@Hg nanoalloy. The enhanced fluorescence signal was quenched selectively by S²⁻ owing to the formation of Ag₂S and HgS. The reported nanosensor was found to be useful for sensing malachite green via the inner filter effect. The linear ranges were 3 nmol L⁻¹ to 13 μmol L⁻¹ for Hg(ii), 3–170 μmol L⁻¹ for S²⁻ and 7–80 μmol L⁻¹ for malachite green, and the corresponding detection limits were 2.1 nmol L⁻¹ for Hg(ii), 1.3 μmol L⁻¹ for S²⁻ and 1.6 μmol L⁻¹ for malachite green.

Gum acacia-stabilized silver nanoparticles for the detection of Hg(ii), S²⁻ and malachite green.     

Stereoselective synthesis of (+)-5-thiosucrose and (+)-5-thioisosucrose

(+)-5-Thiosucrose 1, a novel isosteric sulfur analog of sucrose, was synthesized stereoselectively for the first time via indirect β-d-fructofuranosidation involving selective β-d-psicofuranosidation, followed by stereo-inversion of the secondary hydroxy group at the C-3 position on the furanose ring. Glycosidation of protected 5-thio-d-glucose with a d-psicofuranosyl donor provided β-d-psicofuranosyl 5-thio-α-d-glucopyranoside and that with d-fructofuranosyl donor gave α-d-fructofuranosyl 5-thio-α-d-glucopyranoside. Two anomeric stereocenters of the glycosyl donor and acceptor were controlled correctly to provide a single disaccharide among four possible anomeric isomers in the glycosylation. Conversion of the resulting disaccharides afforded (+)-5-thiosucrose 1 and (+)-5-thioisosucrose 2 in excellent yields, respectively. Inhibitory activities of 1 and 2 against α-glucosidase in vitro were also examined.

(+)-5-Thiosucrose and (+)-5-thioisosucrose were stereoselectively synthesized among four possible anomeric isomers using 5-thio-d-glucose as an α-directing glycosyl acceptor.     

Structure characterization and anticoagulant activity of a novel polysaccharide from Leonurus artemisia (Laur.) S. Y. Hu F

An acidic polysaccharide, named LAP-1, was extracted and isolated from Leonurus artemisia (Laur.), and was further purified with ion exchange chromatography and gel chromatography. The extraction conditions of the crude polysaccharides were optimized by single-factor experiments and response surface methodology. The primary structure of the purified polysaccharide was measured by FT-IR, GC-MS, and NMR. The results showed that LAP-1 was mainly composed of galacturonic acid (GalA), mannose (Man), xylose (Xyl), rhamnose (Rha), arabinose (Ara), glucose (Glc), galactose (Gal), fucose (Fuc), ribose (Rib), and glucuronic acid (GlcA) in the molar ratio of 8.74 : 3.45 : 1.02 : 1 : 2.11 : 5.60 : 4.73 : 1.08 : 1.09 : 1.47. Primary structure analysis results indicated that LAP-1 contained characteristic glycosyl linkages such as →1)-α-d-Manp, →1)-α-d-Glcp, →1)-α-d-Arap-(2→, →1)-β-d-Galp-(3→, →1)-β-d-Manp-(4→, →1)-β-d-Galp-(4→, →1)-β-d-Glcp-(4→, →1)-β-d-GalAp-(4→, →1)-β-d-GlcAp-(4→, →1)-β-d-Manp-(4,6→, →1)-β-d-Manp-(3,4→. The M_w/M_n (PDI), M_n, M_z and M_w of LAP-1 were determined to be 1.423, 6.979 × 10³ g mol⁻¹, 1.409 × 10⁴ g mol⁻¹, and 9.930 × 10³ g mol⁻¹ by HPSEC-MALLS-RID and DLS. SEM, TEM and AFM results indicated that LAP-1 was a highly branched structure. LAP-1 showed mild anticoagulant activity, low toxicity, and less spontaneous bleeding compared with heparin sodium. These results demonstrated the effective coagulation activity of Leonurus artemisia polysaccharides. Thus, the purified LAP-1 could be explored as a promising anticoagulant agent for the treatment of coagulation disorders.

An acidic polysaccharide, denoted LAP-1 was extracted, isolated and purified from Leonurus artemisia (Laur.), in addition to its structure and anticoagulant activity were explored.     

Characterization and adsorption properties of cross-linked yeast/β-cyclodextrin polymers for Pb(ii) and Cd(ii) adsorption

In this study, a crosslinked yeast/β-cyclodextrin polymer (Y–β-CDP), for use as an effective adsorbent for removal Pb(ii) and Cd(ii) ions from aqueous solution, has been innovatively prepared by grafting β-cyclodextrin (β-CD) onto the surface of baker''s yeast (BY) and thiomalic acid as a crosslinker. Several characterization techniques, such as SEM equipped with an EDS analyzer, FTIR, XRD, and XPS were employed characterize the Y–β-CDP. The impact of various operating parameters, such as pH, adsorbent dosage, initial concentration of metal ions, contact time and solution temperature, as well as adsorption kinetics, isotherms and thermodynamics were systematically investigated. The adsorption of Pb(ii) and Cd(ii) on Y–β-CDP reached equilibrium in 25 min, and the kinetic process conforms to the pseudo-second order model. The Langmuir model was used to describe the adsorption isotherm data better than the Freundlich model. The predicted maximum adsorption capacity at 25 °C for Pb(ii) and Cd(ii) was 150.08 and 102.80 mg g⁻¹, respectively, when the initial concentration of metal ions was 120 mg L⁻¹. The thermodynamic analysis revealed that the adsorption procedure of Pb(ii) and Cd(ii) onto Y–β-CDP was spontaneous and endothermic. Furthermore, regeneration experiments demonstrated that Y–β-CDP had excellent recyclability. Together, all results suggested that Y–β-CDP could potentially be a promising adsorbent in the purification of water contaminated with heavy metal ions.

A cross-linked yeast/β-cyclodextrin polymer (Y–β-CDP) was synthesized to remove Pb(ii) and Cd(ii) from aqueous solution.     

l-Menthol alleviates cigarette smoke extract induced lung injury in rats by inhibiting oxidative stress and inflammation via nuclear factor kappa B,p38 MAPK and Nrf2 signalling pathways

l-Menthol is the main ingredient of peppermint which affects various pharmacological effects such as anti-inflammation and anti-oxidative activity. In this study, we aimed to evaluate the potential effects of l-menthol on cigarette smoke extract (CSE) induced lung injury in rats. Morphology assessment results revealed that administration with l-menthol (5, 10 or 20 mg kg⁻¹ d⁻¹) significantly alleviated CSE-induced lung injury. Besides, l-menthol significantly reduced the inflammatory response by suppressing the production of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) via downregulating nuclear factor kappa B (NF-κB) and p38 MAPK pathways. Meanwhile, l-menthol decreased the levels of oxidative stress markers including malondialdehyde (MDA) and myeloperoxidase (MPO) whereas it increased the amount of glutathione (GSH), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) through activation of the Nrf2 pathway. Furthermore, the expression of MMP-9 and TIMP-1 in lungs was reduced after treatment with l-menthol, and this indicated that l-menthol might have a potential effect on airway remodeling. Moreover, immunohistochemistry analyses indicated that l-menthol could suppress the infiltration of CD4⁺ and CD8⁺ T cells in lung tissues and this was probably due to the immune regulation activity of l-menthol. Taken together, our findings support that l-menthol might be a potential candidate for the treatment of CSE-induced lung injury in rats.

l-Menthol is the main ingredient of peppermint which affects various pharmacological effects such as anti-inflammation and anti-oxidative activity.     

Structural characterization and anti-inflammatory effect in hepatocytes of a galactoglucan from Antrodia camphorata mycelium

The galactoglucan ACP2 was isolated from cultured Antrodia camphorata mycelium through anion-exchange column chromatography and Sephadex G-100 chromatography and shown to exhibit hepatoprotective function in L02 cells. Based on monosaccharide composition analysis, ACP2 was mainly composed of glucose, galactose, and 6-deoxyglucose in a molar ratio of 5 : 2 : 1. The average molecular weight of ACP2 was 1.93 × 10⁴ Da. The primary structure of ACP2 was elucidated with Fourier-transform infrared spectroscopy, gas chromatography-mass spectrometry, and nuclear magnetic resonance spectroscopy. The results indicated the following composition: →6)-linked-β-d-Galp-(1→, →6)-linked-α-d-Glcp-(1→, →3)-linked-α-d-Glcp-(1→, and →2,4)-linked-β-d-Glcp-(1→, with terminal 6-deoxy-α-d-Glcp and α-d-Glcp. ACP2 alleviated lipopolysaccharide-induced hepatocyte inflammation by down-regulating the expressions of COX-2, IL-1β, TNF-α and IL-6. The decreased expressions of TLR4, MyD88, NF-κB, and phosphorylated p38 in ACP2-treated L02 cells indicated that ACP2 might ameliorate inflammation through the TLR4 and p38/NF-κB signaling pathways.

A previously undescribed polysaccharide ACP2 was isolated from Antrodia camphorata mycelium. ACP2 ameliorated hepatocyte inflammation through TLR4 and p38/NF-κB signal pathway.     

d-Glucose sensor based on ZnO·V2O5 NRs by an enzyme-free electrochemical approach

A simple wet-chemical technique was used to prepare zinc oxide-doped vanadium pentaoxide nanorods (ZnO·V₂O₅ NRs) in an alkaline environment. The synthesized ZnO·V₂O₅ NRs were characterized using typical methods, including UV-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (XEDS), X-ray photoelectron spectroscopy (XPS), and X-ray powder diffraction (XRD). The d-glucose (d-GLC) sensor was fabricated with modification of a slight coating of nanorods (NRs) onto a flat glassy carbon electrode (GCE). The analytical performances, such as the sensitivity, limit of quantification (LOQ), limit of detection (LOD), linear dynamic range (LDR), and durability, of the proposed d-GLC sensor were acquired by a dependable current–voltage (I–V) process. A calibration curve of the GCE/ZnO·V₂O₅ NRs/Nf sensor was plotted at +1.0 V over a broad range of d-GLC concentrations (100.0 pM–100.0 mM) and found to be linear (R² = 0.6974). The sensitivity (1.27 × 10⁻³ μA μM⁻¹ cm⁻²), LOQ (417.5 mM), and LOD (125 250 μM) were calculated from the calibration curve. The LDR (1.0 μM–1000 μM) was derived from the calibration plot and was also found to be linear (R² = 0.9492). The preparation of ZnO·V₂O₅ NRs by a wet-chemical technique is a good advancement for the expansion of nanomaterial-based sensors to support enzyme-free sensing of biomolecules in healthcare fields. This fabricated GCE/ZnO·V₂O₅ NRs/Nf sensor was used for the recognition of d-glucose in real samples (apple juice, human serum, and urine) and returned satisfactory and rational outcomes.

A simple wet-chemical technique was used to prepare zinc oxide-doped vanadium pentaoxide nanorods (ZnO·V₂O₅ NRs) in an alkaline environment.     

Presence of δ-(l-α-Aminoadipyl)-l-Cysteinyl-d-Valine in Fermentations of Penicillium chrysogenum

Cultures of Penicillium chrysogenum, growth with [³⁵S]sulfate or labeled amino acids, were examined by ion-exchange chromatography for possible peptidic precursors of penicillin. A sulfur-containing compound, present in both the mycelial extracts and the culture filtrates, was eluted at the location of the synthetic lld-tripeptide δ-(l-α-aminoadipyl)-l-cysteinyl-d-valine. Since this compound was also labeled when the cultures were incubated with dl-[6-¹⁴C]α-aminoadipic acid, l-[3,3′-³H]cystine, or dl-[1-¹⁴C]valine, its identity with the synthetic lld-tripeptide can be accepted. No δ-(l-α-aminoadipyl)-l-cysteine or lll-tripeptide were detected. The implications of these findings for tripeptide and penicillin biosynthesis are discussed.     

Remarkable diastereomeric effect on thermoresponsive behavior of polyurethane based on lysine and tartrate ester derivatives

This study describes the long-distance diastereomeric effect on thermoresponsive properties in water-soluble diastereomeric polyurethanes (PUs) composed of an l-lysine ethyl ester diisocyanate and a trimethylene glycol l-/d-tartrate ester, which have differences in spatial arrangements of the ethyl esters in the mirror image. The PUs based on l-lysine and l-/d-tartrate ester, named l-PU and d-PU, were synthesized with various number average molecular weights from 4700 to 13 100. In turbidimetry, l-PU showed a steep phase transition from 100%T to 0%T within about 10 °C at 4 g L⁻¹, whereas d-PU did not change completely to 0%T transmittance even at 80 °C at 4 g L⁻¹. In addition, the thermoresponsive properties of l-PU were less affected by concentration than those of d-PU. This long-distance diastereomeric effect on thermoresponsive behavior between l-PU and d-PU appeared in common among 6 samples with 4700 to 13 100 number average molecular weight. In the dynamic light scattering experiments at each transmittance, the hydrodynamic diameter (D_h) of l-PU increased up to 1000 nm, while the D_h of d-PU remained almost at 200–300 nm. The C O stretching vibration of FT-IR spectra showed that d-PU has more hydrogen-bonded ester groups than L-PU. Thus, we speculated that the difference in the retention of polymer chains in the micelle to promote intermicellar bridging generates the long-distance diastereomeric effect.

The long-distance diastereomeric effect on thermoresponsive properties in a polyurethane system consisting of chiral monomers was reported.     

Ameliorative effect of urolithin A on d-gal-induced liver and kidney damage in aging mice via its antioxidative,anti-inflammatory and antiapoptotic properties

Urolithin A, a metabolite produced by human colon microflora from ellagic acid and related compounds, has been reported to have antioxidant, anti-inflammatory and antiapoptotic properties. The present study investigates the protective effects of urolithin A (Uro A) on d-galactose (d-gal)-induced liver and kidney injury and the possible mechanisms in mice. In this study, we first investigated the antioxidant ability of Uro A in vitro. Then mice were treated with d-gal subcutaneously (150 mg kg⁻¹ d⁻¹), followed by Uro A at different dosages (50, 100, 150 mg kg⁻¹ d⁻¹, administered orally) for 8 weeks. The levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN) and creatinine (Cr) in the serum were tested. Histopathological features were assessed by hematoxylin and eosin (HE) staining followed by an assessment of the antioxidant and anti-inflammatory activities. Furthermore, we also evaluated the expression levels of the genes Bax, Bcl-2 and cleaved caspase-3 in the liver and kidney. The results showed that Uro A treatment obviously attenuated d-gal-induced liver and kidney damage. The beneficial effects of Uro A were accompanied by a decline in malondialdehyde (MDA) levels and a rise in the superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and total antioxidant capacity (T-AOC) activity in the liver and kidney and downregulation of the levels of inflammatory cytokines, such as tumor necrosis factor-α (TNF-α), interleukin-1 beta (IL-1β) and interleukin-6 (IL-6), in serum. Moreover, Uro A could modulate the expression of Bax, Bcl-2 and cleaved caspase-3 in the livers and kidneys of aging mice. These findings suggested that Uro A ameliorated d-gal-induced liver and kidney injury through attenuating oxidative stress, inflammatory responses and apoptosis.

Urolithin A, a metabolite produced by human colon microflora from ellagic acid and related compounds, has been reported to have antioxidant, anti-inflammatory and antiapoptotic properties.