Abstract An efficient synthesis of a series of novel diphenyl N-substituted carbamimidoyl phosphoramidate derivatives was accomplished in two steps. Diphenyl phosphorochloridate (1) was reacted with cyanamide (2) in the presence of 1,4–dimethylpiperazine as a base in THF at 50–55 °C to form an intermediate, diphenyl cyanophosphoramidate (3). Subsequently 3 was reacted with various aromatic/heterocyclic amines (4) in the presence of 1,4–dimethyl piperazine as a base at 55–60 °C to form the corresponding title compounds 5(a-k). The title compounds were tested for antiviral activity against Tobacco mosaic virus (TMV) in vitro, antibacterial and antifungal activities at two different concentrations of 50 and 100 μg/mL. The title compounds exhibited good antiviral and antimicrobial activities when compared to the standards. 相似文献
Using structure-based virtual screening approach, a coumarin derivative (1) was identified as β-glucuronidase inhibitor. A focused library of coumarin derivatives was synthesized by eco-benign version of chemical reaction, and all synthetic compounds were characterized by using spectroscopy. These compounds were found to be inhibitor of β-glucuronidase with IC50 values in a micromolar range. All synthetic compounds exhibited interesting inhibitory activity against β-glucuronidase, however, their potency varied substantially from IC50 = 9.9–352.6 µM. Of twenty-one compounds, four exhibited a better inhibitory profile than the initial hit 1. Interestingly, compounds 1e, 1k, 1n and 1p exhibited more potency than the standard inhibitor with IC50 values 34.2, 21.4, 11.7, and 9.9 µM, respectively. We further studied their dose responses and also checked our results by using detergent Triton ×-100. We found that our results are true and not affected by detergent. 相似文献
The dynamic properties of a biased two-level system in contact with a dissipative bath are studied in the weak coupling limit
using a resolvent expansion method. The theory yields consistent results at low temperatures, a regime in which the widely
used dilute bounce gas approximation (DBGA) to an underlying functional integral expression breaks down. The present results
are however equivalent to a recently adapted functional integral technique that goes beyond the DBGA. The calculated expressions
are relevant for analyzing the neutron scattering data on tunneling of light interstitials, e.g., hydrogen, in metals, at
very low temperatures. 相似文献
Three new amides, pipgulzarine ( 1 ), pipzorine ( 2 ), and piptahsine ( 3 ), have been isolated from the dried seeds of Piper nigrum Linn. along with nine known constituents: (2E,4E,8Z)‐N‐(isobutyl)eicosatrienamide, pellitorine, pipercide, piperine, stigmastanol, stigmasterol, decurrenal, stigmasterol 3‐O‐β‐D ‐glucopyranoside, and 5,10(15)‐cadinen‐4‐ol. The structures of the new constituents have been established as (2E,11E)‐12‐(benzo[1,3]dioxol‐5‐yl)‐N‐(2‐methylpropyl)dodeca‐2,11‐dienamide ( 1 ), (2E,12Z)‐N‐(4‐methylpentyl)octadeca‐2,12‐dienamide ( 2 ), and (2E,4S)‐4‐hydroxy‐N‐(2‐methylpropyl)hex‐2‐enamide ( 3 ). The structures of 1 – 3 were derived by spectral studies and chemical reactions, and by comparison of spectral data in the case of known constituents. Compounds 1 and 2 , and most of the already known compounds, exhibited toxicity against fourth instar larvae of Aedes aegypti Liston. The isolated (Z) double bond in 2 was assigned on the basis of its EI‐MS fragmentation pattern and its reaction with OsO4. The (S) configuration at C(4) of 3 was determined by Horeau's method. This is the first report of the isolation of a 4‐methylpentylamide from P. nigrum, while shorter branched amides have been reported from this genus [1]. 相似文献
Let be a positive integer, and let denote the cyclic group of residues modulo m. Furthermore, let denote the minimum integer N such that for every function there exist m integers satisfying and (and ). It is shown that for every odd prime m.
Daniel Schaal: Partially supported by a South Dakota Governor’s 2010 Individual Research Seed Grant. 相似文献
Journal of Thermal Analysis and Calorimetry - This paper deals with an advanced colorimetric method used to determine the catalase mimetic activity of V2O5 nanoparticles by measuring the decrease... 相似文献
Parthenolide, a strong cytotoxic compound found in different parts of Tarchonanthus camphoratus which motivated the authors to develop an optimized microwave-assisted extraction (MEA) method using Box–Behnken design (BBD) for efficient extraction of parthenolide from the stem of T. camphoratus and its validation by high-performance thin-layer chromatography (HPTLC) and cytotoxic analysis. The optimized parameters for microwave extraction were determined as: 51.5 °C extraction temperature, 50.8 min extraction time, and 211 W microwave power. A quadratic polynomial model was found the most suitable model with R2 of 0.9989 and coefficient of variation (CV) of 0.2898%. The high values of adjusted R2 (0.9974), predicted R2 (0.9945), and signal-to-noise ratio (74.23) indicated a good correlation and adequate signal, respectively. HPTLC analyzed the parthenolide (Rf = 0.16) content in T. camphoratus methanol extract (TCME) at λmax = 575 nm and found it as 0.9273% ± 0.0487% w/w, which was a higher than expected yield (0.9157% w/w). The TCME exhibited good cytotoxicity against HepG2 and MCF-7 cell lines (IC50 = 30.87 and 35.41 µg/mL, respectively), which further supported our findings of high parthenolide content in TCME. This optimized MAE method can be further applied to efficiently extract parthenolide from marketed herbal supplements containing different Tarconanthus species. 相似文献
Wound healing is a complex process which requires an appropriate environment for quick healing. Recently, biodegradable hydrogel-based wound dressings have been seen to have high potential owing to their biodegradability and hydrated molecular structure. In this work, a novel biodegradable composite of sodium alginate hydrogel with wool needle-punched nonwoven fabric was produced for wound dressing by sol–gel technique. The wool nonwoven was dipped in the sodium alginate-water solution and then soaked in calcium chloride solution which resulted in hydrogel formation. FTIR analysis and SEM images confirm the presence of alginate hydrogel inside the needle-punched wool nonwoven fabric. The wound exudate absorbing capacity of hydrogel based wool nonwoven was increased 30 times as compared to pure wool nonwoven. Moreover, the tensile strength and moisture management properties of hydrogel based nonwoven were also enhanced. The unique combination of alginate hydrogel with biocompatible wool nonwoven fabric provides moist environment and can help in cell proliferation during wound healing process.
This review (with 121 references) gives a summary on recent advances in the use of nanomaterials for the optical determination of dopamine. It includes a brief overview of the clinical significance of dopamine followed by a discussion on the recent advances in various nanomaterial-based distinctive optical spectroscopic methods such as (a) colorimetry and spectrophotometry, (b) surface-enhanced Raman spectroscopy (SERS), (c) fluorescence spectrometry, and (d) electrochemiluminescence (ECL) spectrometry. All sections are further divided into subsections based on the type of nanomaterial used, and their advantages and disadvantages are discussed. A discussion on the validity of the nanomaterial-based optical detection of dopamine for human samples is also included. This review concludes with highlights of current challenges of nanomaterial-based optical sensors and an outlook on future perspectives.
Graphical abstract Schematic of the use of various nanomaterials in the detection of dopamine based on colorimetry, spectrophotometry, surface-enhanced Raman spectroscopy, fluorescence and electrochemiluminescence.