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61.
High-grade epithelial ovarian cancer is a fatal disease in women frequently associated with drug resistance and poor outcomes. We previously demonstrated that a marine-derived compound MalforminA1 (MA1) was cytotoxic for the breast cancer cell line MCF-7. In this study, we aimed to examine the effect of MA1 on human ovarian cancer cells. The potential cytotoxicity of MA1was tested on cisplatin-sensitive (A2780S) and cisplatin-resistant (A2780CP) ovarian cancer cell lines using AlamarBlue assay, Hoechst dye, flow cytometry, Western blot, and RT-qPCR. MA1 had higher cytotoxic activity on A2780S (IC50 = 0.23 µM) and A2780CP (IC50 = 0.34 µM) cell lines when compared to cisplatin (IC50 = 31.4 µM and 76.9 µM, respectively). Flow cytometry analysis confirmed the cytotoxic effect of MA1. The synergistic effect of the two drugs was obvious, since only 13% of A2780S and 7% of A2780CP cells remained alive after 24 h of treatment with both MA1 and cisplatin. Moreover, we examined the expression of bcl2, p53, caspase3/9 genes at RNA and protein levels using RT-qPCR and Western blot, respectively, to figure out the cell death mechanism induced by MA1. A significant down-regulation in bcl2 and p53 genes was observed in treated cells compared to non-treated cells (p < 0.05), suggesting that MA1 may not follow the canonical pathway to induce apoptosis in ovarian cancer cell lines. MalforminA1 showed promising anticancer activity by inducing cytotoxicity in cisplatin-sensitive and cisplatin-resistant cancer cell lines. Interestingly, a synergistic effect was observed when MA1 was combined with cisplatin, leading to it overcoming its resistance to cisplatin.  相似文献   
62.
The degradation and mechanical properties of potential polymeric materials used for green manufacturing are significant determinants. In this study, cellulose nanofibre was prepared from Schizostachyum brachycladum bamboo and used as reinforcement in the PLA/chitosan matrix using melt extrusion and compression moulding method. The cellulose nanofibre(CNF) was isolated using supercritical carbon dioxide and high-pressure homogenisation. The isolated CNF was characterised with transmission electron microscopy (TEM), FT-IR, zeta potential and particle size analysis. The mechanical, physical, and degradation properties of the resulting biocomposite were studied with moisture content, density, thickness swelling, tensile, flexural, scanning electron microscopy, thermogravimetry, and biodegradability analysis. The TEM, FT-IR, and particle size results showed successful isolation of cellulose nanofibre using this method. The result showed that the physical, mechanical, and degradation properties of PLA/chitosan/CNF biocomposite were significantly enhanced with cellulose nanofibre. The density, thickness swelling, and moisture content increased with the addition of CNF. Also, tensile strength and modulus; flexural strength and modulus increased; while the elongation reduced. The carbon residue from the thermal degradation and the glass transition temperature of the PLA/chitosan/CNF biocomposite was observed to increase with the addition of CNF. The result showed that the biocomposite has potential for green and sustainable industrial application.  相似文献   
63.
The Friedel–Crafts reaction between substituted indoles as nucleophiles with chalcones-based benzofuran and benzothiophene scaffolds was carried out by employing a highly efficient bimetallic iron–palladium catalyst system. This catalytic approach produced the desired bis-heteroaryl products with low catalyst loading, a simple procedure, and with acceptable yield. All synthesized indole scaffolds 3a–3s were initially evaluated for their cytotoxic effect against human fibroblast BJ cell lines and appeared to be non-cytotoxic. All non-cytotoxic compounds 3a–3s were then evaluated for their anticancer activities against cervical cancer HeLa, prostate cancer PC3, and breast cancer MCF-7 cell lines, in comparison to standard drug doxorubicin, with IC50 values 1.9 ± 0.4 µM, 0.9 ± 0.14 µM and 0.79 ± 0.05 µM, respectively, and appeared to be moderate to weak anticancer agents. Fluoro-substituted chalcone moiety-containing compounds, 3b appeared to be the most active member of the series against cervical HeLa (IC50 = 8.2 ± 0.2 µM) and breast MCF-7 cancer cell line (IC50 = 12.3 ± 0.04 µM), whereas 6-fluroindol-4-bromophenyl chalcone-containing compound 3e (IC50 = 7.8 ± 0.4 µM) appeared to be more active against PC3 prostate cancer cell line.  相似文献   
64.
A novel synthesis of thiazolo[2,3-b]quinazolines 4(a–e), pyrido[2′,3′:4,5]thiazolo[2,3-b]quinazolines {5(a–e), 6(a–e), and 7(a–e)}, pyrano[2′,3′:4,5]thiazolo[2,3-b]quinazolines 8(a–e), and benzo[4,5]thiazolo[2,3-b]quinazoloine9(a–e) derivatives starting from 2-(Bis-methylsulfanyl-methylene)-5,5-dimethyl-cyclohexane-1,3-dione 2 as efficient α,α dioxoketen dithioacetal is reported and the synthetic approaches of these types of compounds will provide an innovative molecular framework to the designing of new active heterocyclic compounds. In our study, we also present optimization of the synthetic method along with a biological evaluation of these newly synthesized compounds as antioxidants and antibacterial agents against the bacterial strains, like S. aureus, E. coli, and P. aeruginosa. Among all the evaluated compounds, it was found that some showed significant antioxidant activity at 10 μg/mL while the others exhibited better antibacterial activity at 100 μg/mL. The results of this study showed that compound 6(c) possessed remarkable antibacterial activity, whereas compound 9(c) exhibited the highest efficacy as an antioxidant. The structures of the new synthetic compounds were elucidated by elemental analysis, IR, 1H-NMR, and 13C-NMR.  相似文献   
65.
The present research work is designed to prepare and evaluate piperine liposomes and piperine–chitosan-coated liposomes for oral delivery. Piperine (PPN) is a water-insoluble bioactive compound used for different diseases. The prepared formulations were evaluated for physicochemical study, mucoadhesive study, permeation study and in vitro cytotoxic study using the MCF7 breast cancer cell line. Piperine-loaded liposomes (PLF) were prepared by the thin-film evaporation method. The selected liposomes were coated with chitosan (PLFC) by electrostatic deposition to enhance the mucoadhesive property and in vitro therapeutic efficacy. Based on the findings of the study, the prepared PPN liposomes (PLF3) and chitosan coated PPN liposomes (PLF3C1) showed a nanometric size range of 165.7 ± 7.4 to 243.4 ± 7.5, a narrow polydispersity index (>0.3) and zeta potential (−7.1 to 29.8 mV). The average encapsulation efficiency was found to be between 60 and 80% for all prepared formulations. The drug release and permeation study profile showed biphasic release behavior and enhanced PPN permeation. The in vitro antioxidant study results showed a comparable antioxidant activity with pure PPN. The anticancer study depicted that the cell viability assay of tested PLF3C2 has significantly (p < 0.001)) reduced the IC50 when compared with pure PPN. The study revealed that oral chitosan-coated liposomes are a promising delivery system for the PPN and can increase the therapeutic efficacy against the breast cancer cell line.  相似文献   
66.
The determination of two imidazoline derivatives [oxymetazoline HCl (OXY) and xylometazoline HCl (XYLO)] was described using different potentiometric platforms. The first electrode type was constructed using tetraphenyl borate (TPB) as anionic exchanger with β-cyclodextrins (β-CD) as ionophore forming oxymetazoline-tetraphenyl borate (OXY-TPB) and xylometazoline-tetraphenyl borate (XYLO-TPB), respectively. The second electrode type was prepared by modification of the first type by conjugation with magnetic iron oxide nanoparticles (MNP) forming (OXY-MNP) and (XYLO-MNP). The synthesized electrodes were fully characterized. The effect of magnetic nano-sized particles as a highly dispersible material with β-CDs on the electrode characteristics was investigated and compared against the classical electrodes. The response time, working pH range and selectivity coefficients were studied. The functionalized nano-electrodes (OXY-MNP and (XYLO-MNP) were found to be more sensitive than the classical electrodes with linearity ranges (1×10−6–1×10−2 M). The functionalized nano-electrodes were successfully applied for the in-line analysis of OXY and XYLO in pharmaceutical dosage forms and spiked rabbit aqueous humor samples with no prior extraction of treatment. This suggests the future use of these electrodes in clinical studies of both drugs of interest.  相似文献   
67.
The formation of host–guest complexes of cucurbit[7]uril (CB7) with the antihistamine drug tripelennamine (TRP) was studied by optical and NMR spectroscopy. The experimental and computational results are consistent with inclusion of a single TRP molecule in CB7. Addition of CB7 has tuned drug protonation states associated with (de)protonation of the ethyldimethylammonium and exocyclic nitrogens with an increase in the associated pKa values by 1.5 and 2.5 units, respectively. The incorporation of antihistamines drugs such as TRP in cucurbiturils could be utilized for switching their capability for selective binding to histamine H1‐receptors, in the future. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
68.
We report the first experimental violation of Bell's inequality in the spatial domain using the Einstein-Podolsky-Rosen state. Two-photon states generated via optical spontaneous parametric down-conversion are shown to be entangled in the parity of their one-dimensional transverse spatial profile. Superpositions of Bell states are prepared by manipulation of the optical pump's transverse spatial parity-a classical parameter. The Bell-operator measurements are made possible by devising simple optical arrangements that perform rotations in the one-dimensional spatial-parity space of each photon of an entangled pair and projective measurements onto a basis of even-odd functions. A Bell-operator value of 2.389+/-0.016 is recorded, a violation of the inequality by more than 24 standard deviations.  相似文献   
69.
A proton spectral editing pulse sequence for the detection of metabolites with spin systems that involve weak coupling is presented. The sequence is based on homonuclear polarization transfer incorporated into the standard PRESS (Point RESolved Spectroscopy) sequence, which is a volume-selective double spin echo method, to enable spatial localization. All peaks in the region of interest are initially suppressed whether they are peaks from the target metabolite or from contaminating background. The target signal is then restored by polarization transfer from a proton that has a resonance outside the suppressed region and to which the target spins are weakly coupled. This is achieved by the application of a 90 degrees hard pulse with phase orthogonal to that of the PRESS excitation pulse at the location of the first echo in PRESS and by optimizing the two PRESS timings, TE(1) and TE(2), for most efficient yield. Background signal not coupled to any protons outside the initially saturated region remains suppressed. The advantage of this sequence compared to multiple quantum filters is that signal from singlet peaks outside the suppressed area are preserved and can thus be used as a reference. The efficacy of the sequence was verified experimentally on phantom solutions of lactate and glutathione at 3.0 T. For the AX(3) spin system of lactate, the sequence timings were optimized by product operator calculations whereas for the ABX spin system of the cysteinyl group of glutathione numerical calculations were performed for sequence timing optimization.  相似文献   
70.
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