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[en] A series of novel benzimidazole derivatives bearing a heterocyclic ring as oxadiazole (21-32), thiadiazole (33-34), triazole (35-36) were synthesized and evaluated for their activities against Coxsackie virus B3 and B6 in Vero cells. Compounds 21-26, 31-36 with moieties of 2'-pyridyl, 3'-pyridyl and 4'-pyridyl at the 2-position and oxadiazoles, thiadiazole, or triazole substituent at the 4- or 5-position generally displayed activities against CVB3 and CVB6. Especially compound 24 (IC50 = 1.08 μg/mL, SI = 61.7 against CVB3) was the promising candidate as lead compound for anti-enteroviral drug. It was observed in the incorporation of heterocyclic rings in benzimidazole at the 5-position could enhance their biological activities
[en] Crystal structures of a membrane protein transporter in three different conformational states provide insights into the transport mechanism. Secondary active transporters move molecules across cell membranes by coupling this process to the energetically favourable downhill movement of ions or protons along an electrochemical gradient. They function by the alternating access model of transport in which, through conformational changes, the substrate binding site alternately faces either side of the membrane. Owing to the difficulties in obtaining the crystal structure of a single transporter in different conformational states, relatively little structural information is known to explain how this process occurs. Here, the structure of the sodium-benzylhydantoin transporter, Mhp1, from Microbacterium liquefaciens, has been determined in three conformational states; from this a mechanism is proposed for switching from the outward-facing open conformation through an occluded structure to the inward-facing open state
[en] A set heterocyclic benzimidazole derivatives bearing 1, 3, 5-triazine group with different substituents at C-2 and C-5 of the benzimidazole ring have been synthesized and evaluated for their antiviral activities against HASV-1. The structures of these compounds have been established by analytical data, IR spectra, H NMR and mass spectra. Compounds 8a and 8b proved to be the most active antiherpetic agents in this study, at EC 50% concentrations of 2.9. 3.4 mg/ml, respectively. Computational evaluation of the quantum chemical descriptors such as hydrphobicity (log P), HOMO-LUMO and the gap energy were calculated and correlated with the antiviral activity. The tested compounds showed proper degree of hydrophobicity (<0.5 ->5). The HOMO-LUMO gap energy values of the tested compounds are comparable with the observed values for the antiviral drug Acyclovir. (author)
[en] Highlights: • The POC Creasensor device is developed for detection of CKD biomarker creatinine. • Creasensor integrates self-powered SIMPLE technology with colorimetric read-out. • For the first time SIMPLE technology is integrated with a biological assay. • Creasensor detects clinically relevant creatinine concentrations in plasma in 5 min. • Creasensor showed excellent ICC of 0.97 with reference values in single blind study. - Abstract: The lab-on-a-chip (LOC) field has witnessed an excess of new technology concepts, especially for the point-of-care (POC) applications. However, only few concepts reached the POC market often because of challenging integration with pumping and detection systems as well as with complex biological assays. Recently, a new technology termed SIMPLE was introduced as a promising POC platform due to its features of being self-powered, autonomous in liquid manipulations, cost-effective and amenable to mass production. In this paper, we improved the SIMPLE design and fabrication and demonstrated for the first time that the SIMPLE platform can be successfully integrated with biological assays by quantifying creatinine, biomarker for chronic kidney disease, in plasma samples. To validate the robustness of the SIMPLE technology, we integrated a SIMPLE-based microfluidic cartridge with colorimetric read-out system into the benchtop Creasensor. This allowed us to perform on-field validation of the Creasensor in a single-blind study with 16 plasma samples, showing excellent agreement between measured and spiked creatinine concentrations (ICC: 0.97). Moreover, the range of clinically relevant concentrations (0.76–20 mg/dL), the sample volume (5 μL) and time-to-result of only 5 min matched the Creasensor performance with both lab based and POC benchmark technologies. This study demonstrated for the first time outstanding robustness of the SIMPLE in supporting the implementation of biological assays. The SIMPLE flexibility in liquid manipulation and compatibility with different sample matrices opens up numerous opportunities for implementing more complex assays and expanding its POC applications portfolio.
[en] Highlights: → Optimum conditions of pigment dying process of high performance fibers were proposed. → The feed-forward bottleneck neural network (FFBN) as a mapping technique was implemented. → We showed the influence of different factors (parameters of pigment dying) on different output responses (quality of pigment dying). - Abstract: Process optimization involves the minimization (or maximization) of an objective function, that can be established from a technical and (or) economic viewpoint taking into account safety of process. The basic idea of the optimization method using neural network (NN) is to replace the model equations (which traditionally obtained using, for example, the surface response design or others methods) by an equivalent NN. The feed-forward bottleneck neural network (FFBN) as a mapping technique is described and evaluated. From the 2D maps the optimal parameters of pigment dyeing of high performance fibers on the bases of poly-amide benzimidazole (PABI) and polyimide (arimid) are discussed. The studied fibers were treated in 32 experiments under the conditions as proposed by the Design of Experiment (DOE), varying five influencing factors. Neural network mapping method enables visualization of process and shows the influence of different factors on different output responses. Optimum parameters were selected upon compromise decision.
[en] Synthesis of 2-(2-Pyridyl) benzimidazole analogs 1-11 have been carried out and evaluated for in vitro beta-glucuronidase inhibitory potential. The compounds 4 (IC/sub 50/ = 4.06 ± 0.34 meuM), 5 (IC/sub 50/ = 09.63 ± 0.81 meuM), 1 (IC/sub 50/ = 19.66 ± 0.44 meuM), 7 (IC/sub 50/ = 24.75 ± 0.25 meuM), 6 (IC/sub 50/ = 26.30 ± 1.37 meuM), and 3 (IC/sub 50/ = 32.11 ± 0.89 meuM), showed beta-glucuronidase inhibitory activity superior to the standard D-saccharic acid 1,4-lactone, with (IC/sub 50/ = 48.4 ± 1.25 meuM). Based on structure-activity relationship, we discover a new class of potent beta-glucuronidase inhibitors. (author)
[en] Main methods for the synthesis of fused imidazole derivatives with a bridgehead nitrogen atom are systematically considered and summarized. The reaction mechanisms that underlie the methods for the synthesis of pyrido[1,2-a]benzimidazoles and related compounds are described. Biological properties and mechanisms of the biological activity of fused azaheterocycles are discussed. The bibliography includes 152 references.
[en] The present work demonstrates the utility of the extended DFT-derived scaled quantum mechanical (SQM) force fields for predicting the product of a chemical synthesis, namely the reaction of 1,3-dihydrobenzimidazol-2-one with BSTFA [N,O-bis(trimethylsilyl)trifluoro-acetamid]. Since the reactant has two tautomeric forms, the structure of product of the silylation reaction is not obvious. The calculated force fields of the potentially possible products were determined at the B3-LYP/6-31G* level and scaled by transferable scale factors obtained from the literature. The calculated SQM infrared (IR) spectra were numerically compared with the experimental IR spectrum of the product of the reaction. Several proximity measures (S scalar product, residual R-factor, and the standard RMS) between the calculated and experimental IR spectra have been calculated concluding that the product of the reaction is 1,3-bis(trimethylsilyl)benzimidazol-2-one. The NMR spectra of the product gave an independent validation of this result. The presented algorithmic method is able to form a basis for a more automatic procedure, e.g., in the field of the combinatorial syntheses. The S-factor seems to be the most useful proximity measure between a calculated and an experimental spectrum