Removal of endocrine‐disrupting compounds from water using macroporous molecularly imprinted cryogels in a moving‐bed reactor

Highly efficient removal of endocrine‐disrupting compounds (EDCs) such as 17β‐estradiol (E2), 4‐nonylphenol (NP) and atrazine from water was achieved using a novel macroporous adsorption medium. The medium consisted of a macroporous poly(vinyl alcohol) (PVA) cryogel with molecularly imprinted polymer (MIP) particles embedded in it. The MIP was prepared using E2, NP and atrazine as templates. The macroporous composite molecularly imprinted cryogels were formed inside the open‐ended protective shells, known as Kaldnes carriers. These adsorbents (defined as Macroporous Gel Particles, MGPs) were evaluated on the removal of E2, NP and atrazine from water using different column configurations, namely column filled with the MGPs (packed‐bed column) and in moving‐bed reactors (defined here as moving‐bed MGPs reactor). Complete binding (> 99%) of E2 from a spiked aqueous solution (1 mg/L) was achieved using E2‐MIP/MGPs in a moving‐bed MGPs reactor at the retention time in the reactor of 4 min, while only 77% was bound to the nonimprinted medium (NIP/MGPs). Similar results were also obtained for the adsorption medium imprinted with atrazine. All contaminants studied (E2, atrazine and NP) were effectively removed from water at low (environmentally relevant) concentrations by the respective adsorption medium.     

Kinetics and Equilibrium Swelling Properties of Hydrophilic Polymethacrylate Networks

Summary: Hydrogels were synthesized by polymerization of 2-Hydroxy ethylmethacrylate (HEMA) in the presence of ethyleneglycoldimethacrylate (EGDMA) as a crosslinking agent. Structural information and thermophysical properties of the hydrogels were analyzed using Fourier-Transform Infrared spectroscopy, thermogravimetrical analysis, and differential scanning calorimetry. The swelling behaviour of the obtained chemically crosslinked P(HEMA-EGDMA) networks in aqueous solution was investigated as a function of the pH value and concentration of crosslinking agent. Plateau values were found at equilibrium swelling for a low pH value after one day swelling, whereas increasing water uptake was obtained for pH = 6.32 even at swelling times of more than five days. For short swelling times, a linear relationship between swelling ratio and time was found. Experimental data were rationalized using Fick's second law of diffusion. For early and moderate times of diffusion, threshold values were found in all cases considered here, indicating a Fickian behaviour below and a non-Fickian diffusion mechanism above the threshold.     

Logarithmic potentials on Pn

We study the projective logarithmic potential ${\mathbb{G}}_{\mu }$ of a probability measure μ on the complex projective space ${\mathbb{P}}^n$. We prove that the range of the operator $\mu ?{\mathbb{G}}_{\mu }$ is contained in the (local) domain of definition of the complex Monge–Ampère operator acting on the class of quasi-plurisubharmonic functions on ${\mathbb{P}}^n$ with respect to the Fubini–Study metric. Moreover, when the measure μ has no atom, we show that the complex Monge–Ampère measure of its logarithmic potential is an absolutely continuous measure with respect to the Fubini–Study volume form on ${\mathbb{P}}^n$.     

Phosphodiesterase-I inhibitor quinovic acid glycosides from Bridelia ndellensis

Quinovic acid-3-O-alpha-L-rhamnopyranoside (1), quinovic acid-3-O-beta-D-fucopyranoside (2), quinovic acid-3-O-beta-D-glucopyranosyl (1 --> 4)-beta-D-fucopyranoside (3), methyl gallate (4) and ethyl gallate (5) were isolated from the ethyl acetate extract of Bridelia ndellensis barks by fractionation. Compounds 1-3 showed significant inhibitory activity against snake venom phosphodiesterase-I.     

Structural determination of prunusins A and B,new C‐alkylated flavonoids from Prunus domestica,by 1D and 2D NMR spectroscopy

Prunusins A (1) and B (2), the new C‐alkylated flavonoids, have been isolated from the seed kernels of Prunus domestica. Their structures were assigned from ¹H and ¹³C nuclear magnetic resonating spectra, DEPT and by correlation spectroscopy, HMQC and HMBC experiments. 3, 5, 7, 4′‐Tetrahydroxyflavone (3) and 3, 5, 7‐trihydroxy‐8, 4′‐dimethoxyflavone (4) have also been reported from this species. Both compounds (1) and (2) showed significant antifungal activity against pathogenic fungus Trichophyton simmi. Copyright © 2009 John Wiley & Sons, Ltd.     

Screening of peptide affinity tags using immobilised metal affinity chromatography in 96-well plate format

A method for high throughput screening of Green Fluorescent Proteins carrying metal binding tags in bacteria was developed. A random four amino acids tag-peptide library was successfully generated in E. coli. A 96-microtiter plate assembled with metal-iminodiacetic acid small cryogel columns was used for library screening. For the first time we were able to simultaneously screen a metal binding peptide tags library obtained from E. coli against different metal ions. From screening 25 different tags, three clones were able to bind to all metal ions studied (Ni2+, Zn2+, Co2+ and Cd2+). It was clearly demonstrated that the new construct could facilitate the screening of large peptide libraries.     

Synthesis,characterization, crystal structure and electrochemical behavior of a nickel(II) complex of 5,6-dihydro-2H-pyran-3-aldehyde thiosemicarbazone

A new Ni^II complex of 5,6-dihydro-2H-pyran-3-aldehyde thiosemicarbazone (HDPTSC) has been synthesized and characterized by microanalyses, magnetic susceptibility, molar conductance measurements and by spectral methods (i.r., u.v.–vis., ¹H-n.m.r.). The structure of [Ni(DPTSC)₂] · B DMF has been solved using X-ray diffraction and found to be highly symmetrical with a trans -arrangement of the two bidentate ligands. The thiosemicarbazone coordinates as an anionic ligand via the thiosemicarbazone moietys azomethine nitrogen and thiolate sulfur [on loss of the N2 hydrogen]. The electrochemical behavior of the ligand and its Ni^II complex, determined by cyclic voltammetry, shows that the redox process of the ligand was highly irreversible, whereas the redox process of the Ni^II complex was observed as a one electron transfer process in a quasi-reversible and diffusion-controlled reaction.     

Identification of alpha-galactosyl epitope mimetics through rapid generation and screening of C-linked glycopeptide library

A general methodology has been established for rapid generation and screening of combinatorial glycopeptide library and subsequent mass spectrometric sequencing to identify the mimetics of Galalpha(1,3)Gal epitopes. Using this approach, several active glycopeptide sequences were recognized and found to inhibit the binding of human natural anti-Gal antibodies with comparable IC(50)s to synthetic Galalpha(1,3)Gal oligosaccharides. The most active glycopeptides detected from the library included Gal-Tyr-Trp-Arg-Tyr, Gal-Thr-Trp-Arg-Tyr, and Gal-Arg-Trp-Arg-Tyr. These glycopeptides showed higher affinities to anti-Gal antibodies than known Galalpha(1,3)Gal peptide mimetics, such as DAHWESWL and SSLRGF. Our results suggest that, by combining a peptide sequence (the "functional" mimic part) with a terminal alpha-linked galactose moiety (the "structural" mimic part), the resulting glycopeptide could be a very good Galalpha(1,3)Gal mimetic. Analysis of these active glycopeptides provided first-hand information regarding the binding site of anti-Gal antibodies to facilitate the structurally based design of more potent and stable inhibitors.     

Quinovic acid glycosides from Mitragyna stipulosa--first examples of natural inhibitors of snake venom phosphodiesterase I

Phytochemical investigations on the non-alkaloidal extracts of Mitragyna stipulosa bark has led to the isolation of a series of triterpenoids mainly consisting of quinovic acid ([structure: see text]) and its glycoside derivatives [structure: see text] and [structure: see text]. The other constituents isolated include alpha-amyrin, 3beta-acetyl ursolic acid and a mixture of oleanolic and ursolic acid and beta-sitosterol glucopyranoside. Their structures were identified by spectral and chemical studies and compounds [structure: see text] and [structure: see text] were, respectively, identified as quinovic acid 3-O-[beta-D-glucopyranoside] (quinovin glycoside C) and quinovic acid 3-O-[beta-D-quinovopyranoside]-27-O-[beta-D-glucopyranosyl] ester. Compounds [structure: see text] and [structure: see text] showed significant inhibitory activity against snake venom phosphodiesterase I.     

Phytochemical Analysis,Antispasmodic, Myorelaxant,and Antioxidant Effect of Dysphania ambrosioides (L.) Mosyakin and Clemants Flower Hydroethanolic Extracts and Its Chloroform and Ethyl Acetate Fractions

Dysphania ambrosioides (L.) Mosyakin and Clemants is an annual or ephemeral perennial herb used traditionally in the Mediterranean region in folk medicine to treat various illnesses, including those related to the digestive system. This study aims to assess the antispasmodic, myorelaxant, and antioxidant effects of D. ambrosioides flower hydroethanolic extract and its chloroform and ethyl acetate fractions in a comparative study to evaluate the result of the extraction type on the potential activity of the extract. Both rat and rabbit jejunum were used to evaluate the antispasmodic and myorelaxant effect, while the antioxidant effect was evaluated using DPPH, a ferric reducing power assay, and a beta-carotene bleaching test. LC/MS-MS analysis was carried out to reveal the composition of the different types of extract. Following the results, the hydroethanolic extract showed a significant myorelaxant effect (IC₅₀ = 0.39 ± 0.01 mg/mL). Moreover, it was shown that the hydroethanolic extract demonstrated the best antispasmodic activity (IC₅₀ = 0.51 ± 0.05 mg/mL), followed by the ethyl acetate (IC₅₀ = 4.05 ± 0.32 mg/mL) and chloroform (IC₅₀ = 4.34 ± 0.45 mg/mL) fractions. The antioxidant tests showed that the hydroethanolic extract demonstrated high antioxidant activity, followed by the ethyl acetate and chloroform fractions. The LC/MS-MS analysis indicates that the plant extract was rich in flavonoids, to which the extract activity has been attributed. This study supports the traditional use of this plant to treat digestive problems, especially those with spasms.