Stopping the reaction with a 5% solution of NaOH to quench residual acetic anhydride caused full decomposition of the product and cleavage of the acetoxy group in position C-7, resulting in the tri-hydroxylated product 6β,7α- dihydroxyroyleanone (DiRoy), isolated in 91% yield as yellow ...
Subsequently, the water layer was separated, and 1 M NaOH was added to make it basic. The solution was then extracted with chloroform. The organic layer obtained from the extraction was evaporated and dissolved in methanol. Eventually, it was prepared as dihydrochlorides by adding an ether/...
The MSWI fly ash sample (10 g) mixed with 200 mL of 1.725% concentration acetic acid was shaken on a rotary shaker at approximately 30 r/min for 18 h. Then, the filtrate was adjusted by nitric acid and was measured by ICP-OES to determine the concentration of the HM elements....
The solution pH was adjusted by the addition of either 0.1 M HCl or 0.1 M NaOH. The point of zero charge (pHPZC) for AC and AC-Ce-1 was determined by measuring the zeta potential as a function of pH. The zeta potential measurements were conducted using a Zeta Potential Analyzer (Model...
The samples were eluted steadily using a mobile phase (0.35 mL/min) of 100 mM NaOH and a stepwise gradient of sodium acetate (from 0 to 25 min, 0–75 mM; 25–30 min, 75–400 mM). Peaks were identified using QuickPeaks in the OriginPro 9.1 suite, which was also used for ...
本品为白色晶状粉末或无色晶体,在水中和乙醇中微溶,在丙酮中不溶。溶于稀碱。.mp.232 ~233C,[a] +919(c=1. 0,0.1mol/LNaOH)。 本品由两个五元环(咪唑啉环和氢化噻吩环)顺式稠合而成,因含脲的结构单元,存在烯醇化的互变异构,烯醇式为体内的活性形式。
The enriched cells were collected through trypsinization, resuspended in 75 mM KCl at 37 °C for 5 min, and fixed with methanol/glacial acetic acid (3:1) at room temperature for 1 h. Sub- sequently, the cells were spread onto clean slides. Images were captured using a Nikon A1R ...
To asolution of o-aminophenol (1.1 g, 10 mmol) in 20 mL of glacial acetic acid andwater (1:1) was added a solution of potassium cyanate (1.6g, 20 mmol) in waterdropwise. The resulting solution was stirred at r.t. for 3 h. After removal ofthe solvent, th...
NaOH. Then, the compound was extracted with EtOAc (6×100 mL). The combined organic layers were dried over with Na2SO4 and filtered, then the solvent was removed to give the desired product as 1.8 g of a light yellow solid with 56% yield. 1H-NMR (400 MHz, DMSO-d6)δ 7.88 (s,...
Then, 1.0 mM DNPH was added followed by addition of 0.4 M NaOH and then absorbance was read by a spectrophotometer (UV-VIS 4000; ORI, Germany) at 500 nm. The enzyme activity was determined by a standard curve by using absorbance of test samples. 2.7.1.2 Determination of AST ...