• it is a dehydrating agent ( allow the reaction to move forward towards ester formation ) . 2) The usage of dehydrating agents ( as CaCl or MgSo4) to remove excess water molecules trapped in the ester layer . B) Synthesis of ester using acetic anhydride :- 1- Add 2-3 ml of acetic anhydride in a large dry test tube then add 3 drops of concentrated sulphuric acid and mix. 2- Get any one of these alcohols (1-propanol, 3-methyl-1- butanol, benzyl alcohol, or 1-octanol) in a small dry test tube . 3- Put the large tube in an ice bath and start to add alcohol by an increasing rate .
Then, water was added dropwise during the mixing process. The above solution converts of colorless to yellow suspension solution which produced TiO2 nanopowder by drying process at 85°C in anstove for 15 hours. Finally, TiO2 nanopowder obtained were treated in furnace at different temperatures (400°C-800°C) for 2 hours. The initial heating rate was maintained at 5 °C/min. 2.3.
Lecturer Date Introduction Theoretical Background Procedure The procedure was segmented into two categories, the reaction set up and the crude product isolation. Reaction set up The magnetic stirrer was prepared through placing it in the fume cupboard. 1 mmol of L-Phenylalanine was placed and weighed in a 5 mL conical vial. After that, a spin vane was inserted into the vial while adding 0.75 mL of 1M H2SO4 solution. During the addition of the sulphuric acid, the solution was stirred at room temperature until the amino acid (L-Phe) completely dissolved.
Determination of antioxidant activity Scavenging DPPH radicals DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) radical is used free radical method is an in antioxidant assay forwas used to evaluate measured the free radical scavenging activity of the lichen extract . Two millilitreers of 0 .05 mg/mL methanol solution of DPPH radical in the concentration of (0 .05 mg/mL) and 1 mL of the lichen extract (1 mg/mL) were placed in cuvettes. The mixture is storewas stored stand at room temperature for 30 min. Then, the absorbance was measured at 517 nm in a spectrophotometer (Jenway, UK). Ascorbic acid was used as a positive control.
Apparatus- Chromatography column: C18 (10 microns particle size), with Guard column Flow rate: 1.2ml/min Pressure: 30-40kgf Wavelength: 326nm Mobile phase: methanol : water (95:5 v/v) Internal standard: retinyl acetate Injection volume: 20µl Procedure for Retinol extraction from serum samples- 1) 100 µl of serum sample and 100 µl of Retinyl acetate were added into 12 X 100mm glass test tubes. Vortex-mixed for 30 seconds. Then, kept them at 4 C for 5 mins. 2) 1mL of hexane was added and vortex-mixed intermittently for 60 sec. 3) Centrifuged at 2500 rpm for 12 mins.
In 10 g dried sediment sample added 7 ml 0.2 M NH4Cl solution. A mixture of 100 ml hexane: acetone (1:1) was used as a solvent to extract pesticides with overnight shaking for 12 h on reciprocal or wrist action shaker at 180 rpm. The extract was carefully decanted through activated florisil column (2-3 cm), giving twice wash with25 ml hexane: acetone (1:1) to the sediments. The elute was then washed with 200 ml water and then again aqueous layer was extracted with 50 ml hexane. Finally the hexane layer was washed with 100 ml water and then evaporated to dryness with a vacuum rotary evaporator.
The incubation mixture contained 2.5 ml of 1.2% (w/v) fibrin, 2.5 ml of 100 mM Tris–HCl buffer, 10 mM CaCl2 (pH 7.8), and 20 µg of enzyme. The incubation was carried out at 37°C for 30 min, and the reaction was stopped by adding 5 ml of 110 mM trichloroacetic acid containing 220 mM sodium acetate and 330 mM acetic acid. This reaction mixture was centrifuged at 3,000×g for 5 min, and the absorbance of the trichloroacetic acid (50 mM) soluble product was determined at 275 nm. One unit of fibrinolytic enzyme activity was defined as the amount of enzyme required to liberate 1 µg of L-tyrosine per minute at 37°C. The total protein determination was performed as described by Lowry et al.
ZPFe (3 mol%) was added to a mixture of a benzoyl chloride (10 mmoL) and an aromatic compound (10 mmoL). The reaction mixture was stirred for the appropriate reaction times at 80 °C (Table 2). After completion of the reaction (monitored by thin-layer chromatography, TLC), the mixture was diluted with Et2O and filtered. The organic layer was washed with 10% NaHCO3 solution and then dried over anhydrous Na2SO4. The solvent was evaporated under reduced pressure and the product purified by column chromatography on silica gel to give the corresponding pure aryl
3.6.4 Assay of Catalase (CAT) Catalase activity was assayed by measuring the inhibition rate of Hydrogen peroxide at 240nm according to the method described by Luck (1974). For this assay, • A 20% homogenate of the leaf extracts of different plants was prepared in phosphate buffer, 0.067 M (pH 7.0). The homogenate was then centrifuged. The supernatant was then used as enzyme extract. • Hydrogen peroxide (H2O2, 2mM) in phosphate buffer (3.0ml) was taken in an experimental cuvette, followed by the rapid addition of 40μl of enzyme extract and mixed thoroughly.
0,1 gr of kaffir lime oil nanocapsule is weighed and diluted to 100 ml using aquadest, taken as much as 1 ml (100x dilution) to put in the reaction tube then 1ml of saturated NaCO3 solution is added to the test tube and incubated for 10 min at room temperature. Then 0.5 ml of the folinciocalteu (Chemix CV, Yogyakarta) reagent and 7.5 ml aquadest were added, the mixture homogenized using vortex and then incubated for 30 min at room temperature under dark environmental conditions. Absorbance of the sample was then measured using a UV-vis spectrophotometer at a wavelength of 770 nm. The total phenol content of the sample was interpreted to be equivalent to gallic acid based on the standard curve of obtained gallic