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601.
A new 1,2,3-triazole sesquiterpenic named (4aR,5aS,7aR,10aR,10bR)-10-benzyl-5,5-dichloro-1,1,4a,7a-tetramethyl-1,2,3,4,4a,5,7a,10,10a,10b decahydrocyclopropa[2′,3′]cyclohepta [1′,2′:3,4]benzo[1,2-d][1,2,3]triazol-7(6H)-one was synthesized by a dipolar cycloaddition 1,3 between benzyl azide and α,β-unsaturated sesquiterpene ketone catalyzed by titanium tetrachloride TiCl4. It was obtained with a good yield and characterized using single-crystal X-ray diffraction technique, infra red (IR) spectroscopy, High Resolution Mass Spectrometry (HRMS), UV-Visible, and 1H and 13C NMR spectroscopies. The optimization by the density functional theory (DFT) method was carried out to study the formation mechanism of the derivative. The selected compounds 1 – 4 exhibited anticancer activities in vitro against namely fibrosarcoma (HT-1080), lung carcinoma (A-549), and breast (MCF-7 and MDA-MB-231 cell lines with IC50 in the range of 10.02–44.71 μM). In addition to using flow cytometry and the apoptosis assay, cell cycle arrest at the S phase (10 μM) and G2/M arrest in (5 and 10 μM) was performed for compound 4 in fibrosarcoma (HT-1080) cancer cells. Results suggested that compound 4 test with good activity against HT-1080 cells with IC50 value from 10.02 μM and induced the apoptotic effect. Theoretical studies were realized to estimate the molecular proprieties that lead to a high potential of cytotoxic effect, which is in agreement with the experimental results.  相似文献   
602.
Antimicrobial resistance is a dramatic global threat; however, the slow progress of new antibiotic development has impeded the identification of viable alternative strategies. Natural antioxidant-based antibacterial approaches may provide potent therapeutic abilities to effectively block resistance microbes’ pathways. While essential oils (EOs) have been reported as antimicrobial agents, its application is still limited ascribed to its low solubility and stability characters; additionally, the related biomolecular mechanisms are not fully understood. Hence, the study aimed to develop a nano-gel natural preparation with multiple molecular mechanisms that could combat bacterial resistance in an acne vulgaris model. A nano-emulgel of thyme/clove EOs (NEG8) was designed, standardized, and its antimicrobial activity was screened in vitro and in vivo against genetically identified skin bacterial clinical isolates (Pseudomonas stutzeri, Enterococcus faecium and Bacillus thuringiensis). As per our findings, NEG8 exhibited bacteriostatic and potent biofilm inhibition activities. An in vivo model was also established using the commercially available therapeutic, adapalene in contra genetically identified microorganism. Improvement in rat behavior was reported for the first time and NEG8 abated the dermal contents/protein expression of IGF-1, TGF-β/collagen, Wnt/β-catenin, JAK2/STAT-3, NE, 5-HT, and the inflammatory markers; p(Ser536) NF-κBp65, TLR-2, and IL-6. Moreover, the level of dopamine, protective anti-inflammatory cytokine, IL-10 and PPAR-γ protein were enhanced, also the skin histological structures were improved. Thus, NEG8 could be a future potential topical clinical alternate to synthetic agents, with dual merit mechanism as bacteriostatic antibiotic action and non-antibiotic microbial pathway inhibitor.  相似文献   
603.
Lupin seeds can represent a valuable source of phenolics and other antioxidant compounds. In this work, a comprehensive analysis of the phytochemical profile was performed on seeds from three Lupinus species, including one cultivar (Lupinus albus) and two wild accessions (Lupinus cossentinii and Lupinus luteus), collected from the northern region of Tunisia. Untargeted metabolomic profiling allowed to identify 249 compounds, with a great abundance of phenolics and alkaloids. In this regard, the species L. cossentinii showed the highest phenolic content, being 6.54 mg/g DW, followed by L. luteus (1.60 mg/g DW) and L. albus (1.14 mg/g DW). The in vitro antioxidant capacity measured by the ABTS assay on seed extracts ranged from 4.67 to 17.58 mg trolox equivalents (TE)/g, recording the highest values for L. albus and the lowest for L. luteus. The DPPH radical scavenging activity ranged from 0.39 to 3.50 mg TE/g. FRAP values varied between 4.11 and 5.75 mg TE/g. CUPRAC values for lupin seeds ranged from 7.20 to 8.95 mg TE/g, recording the highest for L. cossentinii. The results of phosphomolybdenum assay and metal chelation showed similarity between the three species of Lupinus. The acetylcholinesterase (AChE) inhibition activity was detected in each methanolic extract analyzed with similar results. Regarding the butyrylcholinesterase (BChE) enzyme, it was weakly inhibited by the Lupinus extracts; in particular, the highest activity values were recorded for L. albus (1.74 mg GALAE/g). Overall, our results showed that L. cossentinii was the most abundant source of polyphenols, consisting mainly in tyrosol equivalents (5.82 mg/g DW). Finally, significant correlations were outlined between the phenolic compounds and the in vitro biological activity measured, particularly when considering flavones, phenolic acids and lower-molecular-weight phenolics.  相似文献   
604.
Nanoworld is an attractive sphere with the potential to explore novel nanomaterials with valuable applications in medicinal science. Herein, we report an efficient and ecofriendly approach for the synthesis of Nickel oxide nanoparticles (NiO NPs) via a solution combustion method using Areca catechu leaf extract. As-prepared NiO NPs were characterized using various analytical tools such as powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV-Visible spectroscopy (UV-Vis). XRD analysis illustrates that synthesized NiO NPs are hexagonal structured crystallites with an average size of 5.46 nm and a hexagonal-shaped morphology with slight agglomeration. The morphology, size, and shape of the obtained material was further confirmed using SEM and TEM analysis. In addition, as-prepared NiO NPs have shown potential antidiabetic and anticancer properties. Our results suggest that the inhibition of α-amylase enzyme with IC 50 value 268.13 µg/mL may be one of the feasible ways through which the NiO NPs exert their hypoglycemic effect. Furthermore, cytotoxic activity performed using NiO NPs exhibited against human lung cancer cell line (A549) proved that the prepared NiO NPs have significant anticancer activity with 93.349 μg/mL at 50% inhibition concentration. The biological assay results revealed that NiO NPs exhibited significant cytotoxicity against human lung cancer cell line (A549) in a dose-dependent manner from 0–100 μg/mL, showing considerable cell viability. Further, the systematic approach deliberates the NiO NPs as a function of phenolic extracts of A. catechu with vast potential for many biological and biomedical applications.  相似文献   
605.
Adsorption of CO(2) was investigated on a series of primary, secondary, and tertiary monoamine-grafted pore-expanded mesoporous MCM-41 silicas, referred to as pMONO, sMONO, and tMONO, respectively. The pMONO adsorbent showed the highest CO(2) adsorption capacity, followed by sMONO, whereas tMONO exhibited hardly any CO(2) uptake. As for the stability in the presence of dry CO(2), we showed in a previous contribution [J. Am. Chem. Soc.2010, 132, 6312-6314] that amine-supported materials deactivate in the presence of dry CO(2) via the formation of urea linkages. Here, we showed that only primary amines suffered extensive loss in CO(2) uptake, whereas secondary and tertiary amines were stable even at temperature as high as 200 °C. The difference in the stability of primary vs secondary and tertiary amines was associated with the occurrence of isocyanate as intermediate species toward the formation of urea groups, since only primary amines can be precursors to isocyanate in the presence of CO(2). However, using a grafted propyldiethylenetriamine containing both primary and secondary amines, we demonstrated that while primary amines gave rise to isocyanate, the latter can react with either primary or secondary amines to generate di- and trisubstituted ureas, leading to deactivation of secondary amines as well.  相似文献   
606.
Nine compounds have been isolated for the first time from Celtis africana, namely trans-N-coumaroyltyramine (1), trans-N-feruloyltyramine (2), trans-N-caffeoyltyramine (3), lauric acid (4), oleic acid (5), palmitic acid (6), lupeol (7), β-sitosterol (8) and oleanolic acid (9), respectively. Their structures have been elucidated by different spectroscopic techniques. The isolated compounds were screened for their antioxidant, anti-inflammatory and acetylcholinestrease enzyme inhibitory activities. Compounds 1-3 showed significant antioxidant and anti-inflammatory activities and weak to moderate acetylcholinestrease enzyme inhibition activity.  相似文献   
607.
The trimeric, cyclic polyanion [(α-Ti3GeW9O37OH)3(TiO3(OH2)3)]17? (Ti10) was synthesized by reaction of [A-α-GeW9O34]10? with K8[Ti4O4(C2O4)8] in a mixture of rubidium and lithium acetate buffers at 60 °C, and then crystallized as a mixed rubidium-potassium-sodium salt, Rb13K2Na2[(α-Ti3GeW9O37OH)3(TiO3(OH2)3)]·40H2O (Rb-Ti10). The title compound was characterized in the solid state by IR, single-crystal XRD, TGA and elemental analysis, and in solution by 183W-NMR. In order to prepare a pure sample of Rb-Ti10, several reaction parameters need to be carefully controlled, such as the ratio of rubidium and lithium acetate buffers, the choice of titanium precursor (K8[Ti4O4(C2O4)8]), the reaction temperature, and very importantly, the concentration of rubidium ions.  相似文献   
608.
609.
Polycrystalline samples of oxygen deficient perovskites SrFe1?xScxO3?δ (0  x  0.5) have been synthesized by direct solid state reactions. Each compound has been stabilized with two different oxygen stoichiometries. The structural study shows, firstly, the good cationic homogeneity of the samples and, secondly, that the Sc and Fe atoms are randomly distributed over the same crystallographic site, whatever the scandium content. This implies that no anionic order is possible. A detailed Mossbauer spectroscopy study clearly shows that the substitution of scandium for iron involves an oxygen content decrease which decreases the tetravalent iron content until its total disappearance for x = 0.5. The evolutions of the isomer shift, the quadrupolar splitting and the relative intensity versus the Sc3+ content are depicted in the present paper.  相似文献   
610.
Adsorption of carbon dioxide (CO2) was investigated on triamine-grafted, pore-expanded MCM-41 mesoporous silica (TRI-PE-MCM-41). Measurements of adsorption capacity using mass spectrometry showed an enhanced CO2 adsorption capacity in humid streams compared to dry CO2. This was corroborated with breakthrough experiments, which also showed that TRI-PE-MCM-41 offered a practically infinite selectivity towards CO2 over nitrogen. Cyclic measurements of pure CO2 and CO2:N2 = 10:90 mixture using different regeneration modes showed that amine-grafted PE-MCM-41 is particularly suitable for CO2 removal using temperature swing adsorption (TSA) at adsorption temperatures higher than ambient, while temperature-vacuum swing adsorption (TVSA) may be attractive at ambient temperature.  相似文献   
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