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排序方式: 共有179条查询结果,搜索用时 15 毫秒
21.
Luojuan Hu Tim Quach Sifei Han Shea F. Lim Preeti Yadav Danielle Senyschyn Natalie L. Trevaskis Jamie S. Simpson Christopher J. H. Porter 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2016,128(44):13904-13909
First‐pass hepatic metabolism can significantly limit oral drug bioavailability. Drug transport from the intestine through the lymphatic system, rather than the portal vein, circumvents first‐pass metabolism. However, the majority of drugs do not have the requisite physicochemical properties to facilitate lymphatic access. Herein, we describe a prodrug strategy that promotes selective transport through the intestinal lymph vessels and subsequent release of drug in the systemic circulation, thereby enhancing oral bioavailability. Using testosterone (TST) as a model high first‐pass drug, glyceride‐mimetic prodrugs incorporating self‐immolative (SI) spacers, resulted in remarkable increases (up to 90‐fold) in TST plasma exposure when compared to the current commercial product testosterone undecanoate (TU). This approach opens new opportunities for the effective development of drugs where oral delivery is limited by first‐pass metabolism and provides a new avenue to enhance drug targeting to intestinal lymphoid tissue. 相似文献
22.
Preeti Jain Vandna Singh Sabir Ali Vishwas Tripathi Upendra Saraswat 《Journal of Saudi Chemical Society》2018,22(5):546-557
Macrocyclic Schiff base ligand through the condensation of 1,3-dicarbonyl-phenyl-dihydrazide with 4,4′-difluorobenzil and its Co(II), Ni(II), Cu(II) and Zn(II) metal complexes have been synthesized. The ligand and metal complexes were characterized by analytical and physicochemical methods. An octahedral geometry arising from coordination of N2O2 donor atoms from the macrocyclic framework has been proposed for all metal complexes. Synthesized ligand and metal complexes were investigated for in vitro antibacterial and antioxidant activity. Complex [Ni(C22H14N4F2O2)(OCOCH3)2] has shown remarkable antibacterial activity (Minimum inhibitory concentration 8–16?μg/ml) comparable to commercial antibiotic Ciprofloxacin. Anticancer activity of synthesized compounds against Squamous Cell Carcinoma (SCC4), head and neck cancer cell line has also been studied at different concentrations and at different time points. Complexes [Co(C22H14N4F2O2)(NO3)2] and [Cu(C22H14N4F2O2)(OCOCH3)2] have shown remarkable anticancer results (IC50 31.1 and 43.1?μM) against the tested cell line in concentration dependent manner. Molecular docking studies were carried out to find the binding mode of the synthesized macrocyclic Schiff base ligand to Epidermal Growth Factor Receptor (EGFR) Kinase (PDB ID: 1M17). 相似文献
23.
Bhushan KR Liu F Misra P Frangioni JV 《Chemical communications (Cambridge, England)》2008,(37):4419-4421
Microwave-assisted synthesis of near-infrared fluorescent sphingosine derivatives is described, and the utility of the probes demonstrated by co-localization studies with visible wavelength fluorescent sphingosine derivatives. 相似文献
24.
A variety of alcohols react with 2,3,4,6-tetra-O-acetyl-1,5-anhydro-D-arabino-hex-1-enopyranose 1 in the presence of a catalytic amount of HClO(4) supported on silica gel to give the corresponding alkyl 3-deoxy-hex-2-enopyranosides 2 in high yield, with short reaction times (10-45 mins) and good alpha-selectivity. Work-up merely involves filtration of the reagent, followed by chromatographic purification of the crude product. This methodology has also been employed in the synthesis of a bicyclic ether, a useful precursor for cyclic polyethers, and a 4-amino-C-glucoside. 相似文献
25.
26.
Raveendran Sindhu Mathiyazhakan Kuttiraja Parameswaran Binod Varghese Elizabeth Preeti Soolankandath Variem Sandhya Sankar Vani Rajeev Kumar Sukumaran Ashok Pandey 《Applied biochemistry and biotechnology》2012,167(6):1513-1526
Sugarcane tops is one of the largest biomass resources in India and in tropical countries such as Brazil in terms of surplus availability. Conversion of this feedstock to ethanol requires pretreatment to make it more accessible for the enzymes used in saccharification. Though several pretreatment regimens have been developed for addressing biomass recalcitrance, very few seem to be promising as an industrial process. A novel hybrid method involving use of mild acid and surfactant was developed which could effectively remove lignin and improve the sugar yield from sugar cane tops. Operational parameters that affect the pretreatment efficiency (measured as yield of sugars) were studied and optimized. Changes in structural properties of the biomass were studied in relation to the pretreatment process using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier Transform Infrared (FTIR) analysis, and the changes in chemical composition was also monitored. The biomass pretreated with the optimized novel method could yield 0.798?g of reducing sugars per gram of pretreated biomass upon enzymatic hydrolysis. 相似文献
27.
Hanna GohMin Joung Kim Preeti SalujaNarinder Singh Doo Ok Jang 《Tetrahedron letters》2012,53(30):3900-3902
A dipodal receptor was synthesized by condensation of isophthalaldehyde and p-toluenesulfonylhydrazide. The receptor was found to be selective for Cu2+ recognition in CH3CN. The resultant Cu2+ receptor complex selectively recognized iodide through cation displacement assay in a CH3CN/H2O (8:2, v/v) solvent system. 相似文献
28.
By examining some known wave equations it is shown that the dynamics of a free quantum particle in a slightly noncommutative space-time is equivalent to that of a charged particle moving in a self-generated (weak) electromagnetic field.Presented at the 5th International Colloquium on Quantum Groups: Quantum Groups and Integrable Systems, Prague, 20–22 June 1996. 相似文献
29.
An h-deformation of a (graded) Hopf algebra of functions on supergroup GL(11) is introduced via a contraction of GL
q
(11). The deformation parameter h is odd (Grassmann). A related differential calculus on h-superplane is presented. 相似文献
30.
Preeti G. Joshi Kunju Joshi Sudha Mishra Nanda B. Joshi 《Photochemistry and photobiology》1994,60(3):246-248
Abstract The plasma membrane has been implicated as a critical target of photodynamic action on cells. We have observed that the photosensitization of human cerebral glioma (U-87 MG) cells by hematoporphyrin derivative (HpD) causes a large increase in intracellular calcium [Ca2+ ]. This increase in [Ca2+ ]i was solely due to the influx of extracellular Ca2+ through the plasma membrane and showed a dependence on HpD concentration, light dose and concentration of calcium in the extracellular medium. The magnitude of the Ca2+ influx decreased with increasing postirradiation time, which suggests that the cell membrane partially recovers from the photodynamic injury. The photoinduced Ca2+ influx was inhibited by the Ca2+ channel blocker diltiazem and the reducing agent dithioerythritol. These findings are discussed in terms of possible activation of a Ca2+ channel as a result of photosensitization. 相似文献