Synthesis of novel glycodendrimer scaffolds containing hypervalent sugar pyranosides and triazole bridging points is described. Dendrimers with a greater number of bridging triazole units and α-d-glycopyranosyl surface groups exhibit better anti-arthritic and anti-inflammatory activity than dendrimers with less number of triazole and α-d-glycopyranosyl units. 相似文献
Buagafuran is a novel drug candidate derived from natural product.Its absolute configuration has been confirmed by electronic circular dichroism combined with modern quantum-chemical calculation using time-dependent density functional theory.The predicted UV absorbance peak is underestimated by several nanometers compared with the experimental data.The applicability of empirical rule for the C=C-C-O system in Buagafuran has also been discussed.Our results show that electronic circular dichroism could be a useful tool for the absolute configuration assignment of chiral drugs,especially for the oily or semisolid substances,whose crystal structures are impossible to obtain. 相似文献
An optimum nanoprecipitation technique for gelatin nanoparticles is established, based on aqueous gelatin solution and ethanolic solution containing stabilizer. Crosslinking with glutaraldehyde results in stable gelatine nanoparticles. Several factors such as the surfactant concentration, type of surfactant, type of nonsolvent and gelatin concentration are evaluated. Gelatin nanoparticles with 200–300 nm can be produced using 20–30 mg mL?1 of gelatin and a minimum of 7% w/v stabilizer (Poloxamer 407 or 188). Furthermore, methanol and ethanol are good nonsolvents, whereas other nonsolvents such as acetone, isopropyl alcohol, and acetonitrile, result in phase separation and visible precipitates. The entrapment efficiency of fluorescein‐isothiocyanate (FITC)‐dextran as model drug was determined to 50% with no substantial effect on particle size. 80% of the drug is only released after enzymatic digestion.
A simple, rapid, and highly sensitive method for simultaneous analysis of anti‐inflammatory drugs (naproxen, ibuprofen, and mefenamic acid) in diluted human serum was developed using the electrochemically controlled solid‐phase microextraction coupled to ion mobility spectrometry. A conducting molecularly imprinted polymer film based on polypyrrole was synthesized for the selective uptake and release of drugs. The film was prepared by incorporation of a template molecule (naproxen) during the electropolymerization of pyrrole onto a platinum electrode using cyclic voltammetry method. The measured ion mobility spectrometry intensity was related to the concentration of analytes taken up into the films. The calibration graphs (naproxen, ibuprofen, and mefenamic acid) were linear in the range of 0.1–30 ng/mL and detection limits were 0.07–0.37 ng/mL and relative standard deviation was lower than 6%. On the basis of the results obtained in this work, the conducting molecularly imprinted polymer films as absorbent have been applied in the electrochemically controlled solid‐phase microextraction and ion mobility spectrometry system for the selective clean‐up and quantification of trace amounts of anti‐inflammatory drugs in human serum samples. Scanning electron microscopy has confirmed the nano‐structure morphology of the polypyrrole film. 相似文献
A simple adsorption/desorption procedure using a mixed matrix membrane (MMM) as extraction medium is demonstrated as a new miniaturized sample pretreatment and preconcentration technique. Reversed-phase particles namely polymeric bonded octadecyl (C18) was incorporated through dispersion in a cellulose triacetate (CTA) polymer matrix to form a C18-MMM. Non-steroidal anti-inflammatory drugs (NSAIDs) namely diclofenac, mefenamic acid and ibuprofen present in the environmental water samples were selected as targeted model analytes. The extraction setup is simple by dipping a small piece of C18-MMM (7 mm × 7 mm) in a stirred 10 mL sample solution for analyte adsorption process. The entrapped analyte within the membrane was then desorbed into 100 μL of methanol by ultrasonication prior to high performance liquid chromatography (HPLC) analysis. Each membrane was discarded after single use to avoid any analyte carry-over effect. Several important parameters, such as effect of sample pH, salting-out effect, sample volume, extraction time, desorption solvent and desorption time were comprehensively optimized. The C18-MMM demonstrated high affinity for NSAIDs spiked in tap and river water with relative recoveries ranging from 92 to 100% and good reproducibility with relative standard deviations between 1.1 and 5.5% (n = 9). The overall results obtained were found comparable against conventional solid phase extraction (SPE) using cartridge packed with identical C18 adsorbent. 相似文献
Dopamine, rotigotin, ladostigil, and rasagiline analogues 2-amino-4,5,6-trimethoxyindane and 1-amino-5,6,7-trimethoxyindane were synthesized starting from 5,6,7-trimethoxyindan-1-one for the first time with 34% and 45% total yields. α-Carboxylation of indanone, reduction of ketone group with Et3SiH, basic hydrolysis of ester, Curtius reaction of the acid, and addition of BnOH afforded the corresponding carbamate. Pd-C-catalyzed hydrogenolysis of carbamate and deprotonation of amine hydrochloride with NaOH gave the dopamine and rotigotin analogue 2-aminoindane. Reduction of 5,6,7-trimethoxyindan-1-one with NaBH4 afforded the alcohol, which was then converted to the azide derivative via Mitsunobu reaction with diphenylphosphoryl azide; Pd-C catalyzed hydrogenation of the azide to the amine hydrochloride and then deprotonation of the amine hydrochloride with NaOH furnished the ladostigil and rasagiline analogue 1-aminoindane. These amines and BnOH were reacted with CSI to produce sulfamoyl carbamates, which were converted to sulfamides via Pd-C-catalyzed hydrogenolysis reaction with 20% and 25% total yields. 相似文献
The conformational state of 8‐chloro‐1‐methyl‐2,3,4,5‐tetrahydro‐1H‐3‐benzazepine hydrochloride (lorcaserin) in water has been determined on the basis of one‐bond and long‐range C? H residual dipolar coupling (RDC) data along with DFT computations and 3JHH coupling‐constant analysis. According to this analysis, lorcaserin exists as a conformational equilibrium of two crown‐chair forms, of which the preferred conformation has the methyl group in an equatorial orientation. 相似文献