• 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.
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. Characterization 2.3.1 UV- Visible diffuse reflectance spectroscopy (DRS)
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.
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.
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.
Total essential oils analysis method is conducted based on Ali  with modification. 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
The silver ion TLC was prepared through the following procedure: Silver nitrate was dissolved in 10 ml of distilled water. This aqueous solution of silver nitrate was absolutely mixed with 9 g of silica gel (10 ~ 40 μm particles). Then, a 10 × 5 cm TLC plate was coated with the above slurry and activated for 1 h at 90 °C before use. They were immediately transferred into a desiccator in dark for storage after cooling. 32 100 μL of afore-prepared sample solution and the mixed reference standard were diluted 100 times with ethyl acetate.
The objective of this experiment was to create synthesize methyl eugenol from eugenol, dimethyl carbonate, and tetrabutylammonium bromide. To start off the experiment, a heating under reflux apparatus was used and the parts included: a water jacketed condenser, ring stand, tubes, flowing water, 25-mL round bottom flask, heating block, and a hot plate. There were two parts to the water condenser, entry and exit ways for water. The bottom opening was connected to the sink through one tube and the top opening was connected with a loose end, which was needed to get rid of the flowing water. To create the solution needed to synthesize methyl eugenol, approximately 0.200 g of eugenol (note: the measured g was converted to mg for later calculations) was measured, alongside approximately 1.2 g of TBAB and was added to the 25-mL round bottom flask.