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A library of molecularly imprinted polymers (MIPs) was synthesized by radical bulk polymerization using the beta-lactam antibiotic penicillin G as the template. Diversity of the library was obtained by combining various functionalized monomers and cross-linkers and by varying the stoichiometry and the concentration of the components in the prepolymerization mixtures. The library was screened for selectivity to penicillin G by a radioligand binding assay and was compared to a corresponding control library. The best MIP candidate, showing the highest selectivity for penicillin G, was prepared from methacrylic acid and trimethylolpropane trimethacrylate as the functionalized monomer and cross-linker, respectively. Cross-reactivity studies with other beta-lactam antibiotics showed a low cross-reactivity of penicillin V (15%), ampicillin (16%), and amoxicillin (19%). Nafcillin and oxacillin showed less cross-reactivity (<1%). Cross-reaction with a cephalosporin antibiotic (cephapirin) and structurally nonrelated antibiotics (chloramphenicol, tetracycline, dapsone, and erythromycin) was less than 0.01%. 相似文献
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Kirsten Berger Johanna Josefine Ostberg-Potthoff Tamara Bakuradze Peter Winterhalter Elke Richling 《Molecules (Basel, Switzerland)》2020,25(22)
Red fruits and their juices are rich sources of polyphenols, especially anthocyanins. Some studies have shown that such polyphenols can inhibit enzymes of the carbohydrate metabolism, such as α-amylase and α-glucosidase, that indirectly regulate blood sugar levels. The presented study examined the in vitro inhibitory activity against α-amylase and α-glucosidase of various phenolic extracts prepared from direct juices, concentrates, and purees of nine different berries which differ in their anthocyanin and copigment profile. Generally, the extracts with the highest phenolic content—aronia (67.7 ± 3.2 g GAE/100 g; cyanidin 3-galactoside; chlorogenic acid), pomegranate (65.7 ± 7.9 g GAE/100 g; cyanidin 3,5-diglucoside; punicalin), and red grape (59.6 ± 2.5 g GAE/100 g; malvidin 3-glucoside; quercetin 3-glucuronide)—showed also one of the highest inhibitory activities against α-amylase (326.9 ± 75.8 μg/mL; 789.7 ± 220.9 μg/mL; 646.1 ± 81.8 μg/mL) and α-glucosidase (115.6 ± 32.5 μg/mL; 127.8 ± 20.1 μg/mL; 160.6 ± 68.4 μg/mL) and, partially, were even more potent inhibitors than acarbose (441 ± 30 μg/mL; 1439 ± 85 μg/mL). Additionally, the investigation of single anthocyanins and glycosylated flavonoids demonstrated a structure- and size-dependent inhibitory activity. In the future in vivo studies are envisaged. 相似文献
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Haiwen Zhang Jennifer E. Enman Maren L. Conrad Marcy J. Manning Courtney S. Turner Susan L. Wheaton Christopher M. Vogels Stephen A. Westcott Andreas Decken Felix J. Baerlocher 《Transition Metal Chemistry》2006,31(1):13-18
Pyridinecarboxaldimines (N–N′) derived from pyridin-2-ylcarboxaldehydes and unsaturated amines add to [PdCl2(coe)]2 (coe = cis-cyclooctene) to give complexes of the type PdCl2(N–N′) in moderate yields. The palladium complexes have been investigated as substrates for hydroboration reactions and as
antifungal agents against Aspergillus niger, A. flavus, Candida albicans, and Saccharomyces cerevisiae. 相似文献
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Dr. Palraj Kasinathan Dr. Charlotte Lang Dr. Sambhu Radhakrishnan Dr. Josefine Schnee Cécile D'Haese Dr. Eric Breynaert Prof. Johan A. Martens Prof. Eric M. Gaigneaux Prof. Alain M. Jonas Dr. Antony E. Fernandes 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(27):6753-6762
Solid acid catalysts are central in our chemical industry and are major players in the valorization of bioresources. However, there is still a need to develop solid acid catalysts with enhanced acid strength and improved, or tunable, physicochemical profile to enhance the efficiency and sustainability of chemical processes. Here, a modular approach to tune the acid strength and surface polarity of silica-supported sulfonic acid catalysts, based on a versatile copper-catalyzed azide–alkyne cycloaddition (CuAAC)-based anchoring scheme, is presented. The CuAAC-formed triazole link was used to enhance the activity of the grafted sulfonic acids and to pair the acid sites with secondary hydrophobic functions. The beneficial effects of both the triazolium link and the paired hydrophobic site, as well as the optimal positioning of the sulfonic moiety on the triazole ring, are discussed in model esterification reactions. 相似文献
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Christian Slugovc Sandra Demel Silvia Riegler Josefine Hobisch Franz Stelzer 《Macromolecular rapid communications》2004,25(3):475-480
Summary: A model study with four norbornene derivatives with different groups connecting a functional unit to the norbornene reveals that the “anchor groups” influence the polymerisation rate constants of ring opening metathesis (ROM) polymerisations. Consequently, polydispersities and molecular weights are affected. The observed effects are explained by different tendencies of the anchor groups to coordinate to the ruthenium centre during the resting state of the propagation.
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Robert Saf Gerald Schwarzenbacher Christian Mirtl Gertraud Hayn Josefine Hobisch Karl Gatterer 《Macromolecular rapid communications》2004,25(9):911-915
Summary: Poly(ethylene oxide) methyl ether 4H‐1,2,4‐triazol‐4‐yl ( 1 ) has been synthesized as a novel macroligand. ESI‐MS (electrospray ionisation mass spectrometry), MALDI‐TOF (matrix‐assisted laser desorption ionisation time‐of‐flight) MS as well as NMR spectroscopy were used for the accurate determination of number‐average molecular weights ( ), the crucial parameter for subsequent synthesis of metal‐polymer complexes of four different samples 1a – d . Reaction of polymer 1a with [Fe(H2O)6](nps)2 (nps = 3‐nitrophenylsulfonate) gave [Fe( 1a )3](nps)2, a bistable metal‐polymer complex that exhibited low‐spin (LS) to high‐spin (HS) transitions around T1/2 = 257 K, accompanied by a change in colour from violet (LS) to slightly yellow (HS).
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Berit Schneider Eleonore Cohen Josefine Stani Andrea Kolbus Margarethe Rudas Reinhard Horvat Michael van Trotsenburg 《Journal of voice》2007,21(4):502-507
BACKGROUND: The human larynx is assumed to be a steroid receptor target organ. There are only very limited data on the evidence of steroid receptors in the vocal folds, although voice alterations due to hormonal influence and treatment have been found. GOAL OF THE STUDY: To investigate the expression of estrogen alpha, progesterone, and androgen receptors in human vocal folds (vocalis muscle, glands, lamina propria, epithelium). METHODS: Immunohistochemically, vocal fold cadaver specimens of 15 autopsied patients (6 women, 9 men), which were taken approximately 4 to 8 hours postmortem were investigated. Furthermore, one (male) vocal fold biopsy obtained intraoperatively during a laryngectomy was tested. RESULTS: No specific immunohistochemical staining for the different types of steroid hormones investigated could be observed in either the postmortem taken biopsies nor the intraoperatively one. However, several unspecific staining patterns could be observed. CONCLUSION: The results of this study contradict recently published data and question the expression of sex hormone receptors in the vocal folds. Main causes of false interpretations of unspecific staining are discussed. 相似文献