Sterols in plants are almost completely derived from acetyl-coenzyme A (acetyl-CoA). Acetyl-CoA is dimerized to acetoacetyl-CoA that then forms 3- hydroxy-3-methylglutaryl-CoA (HMG-CoA) by a condensation reaction. HMG-CoA is reduced to mevalonic acid by 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR), a rate-limiting step in human isoprenoid biosynthesis. HMGR over-expression in transgenic tobacco plants resulted in increased levels of total sterols, indicating that HMGR is a limiting enzyme also in plant sterol biosynthesis (Schaller et al., 1995). The next step in sterol synthesis is to form squalene from mevalonic acid, and this is performend by a series of reactions where the final step is catalysed by the squalene synthase enzyme (SQS).…
Doc. Anthony Miller, a physicist, and an engineer, with him Doc. Stephen Strange who had the same expertise as Doc. Anthony Miller. They were transported to Area 51 which was a secret military facility, they were brought there to work on a project.…
Purpose- By completing this lab I had hoped to accomplish finding out which gum brand gives you the best flavor. I was testing the price of gum compared to how long the flavor lasted, I thought that the more expensive the gum was the longer the flavor would last because when you buy a more expensive product it tends to be better quality as with shirts, so I thought the same would go for gum flavor. Hypothesis-…
The extraction lab began with a .517g mixture of benzoic acid, p-nitroaniline, and azobenzene charged in a 125 mL Erlenmeyer flask mixed with 50 mL of Et2O. Once dissolved, the mixture is transferred the mixture into separatory funnel and begin acid extraction. 15 mL of 3 M HCl is added to the separatory funnel and inverted until a phase boundary is present. An additional 15 mL of 3 M HCl was then added and inverted again. The aqueous layer was removed through the separatory funnel and placed in a 250 mL Erlenmeyer flask labeled “acid.” 15 mL of a 3 M NaOH is added to the organic phase remaining in the separatory funnel and inverted until a phase boundary is formed.…
A magnetic stirrer was placed into the beaker and the reaction was heated in a 50℃ water bath. The reaction mixture was heated and stirred for 5 minutes until the salicylic acid dissolved. The mixture was set aside to cool down to room temperature and crystallize in the beaker. Afterwards 6 mL of cold deionized water was added to the crystals (aspirin). The crystals were separated from the mixture through vacuum filtration using a Hirsch funnel.…
In this lab, we carried out a variety of reactions using different chemicals and metals. A chemical reaction is when the chemical state of the substance you are testing rearranges its ionic and molecular structure. One of the reactions we experienced was single replacement, this consists of one ion switching places with another ion to form a new compound. Another reaction we saw was double replacement. In this reaction, two compounds ions are switched to form two new compounds.…
The goal of this lab was to prepare methyl m-nitrobenzoate using electrophilic aromatic substitution. An example of electrophilic aromatic substitution is nitration where a hydrogen atom which is part of a aromatic ring is substituted by an electrophile. For benzene, aromaticity is a stabilizing feature. As such, instead of undergoing electrophilic additions, it undergoes electrophilic substitutions.…
To improve the yield of the ester the reaction should be heated using a high temperature. This would favour the formation of the products in this reaction, as the formation of an ester (esterification) is an endothermic reaction. Thus use of a high temperature will push the equilibrium to the right hand side, and a larger yield of the ester will be produced. To improve the yield of the Ester the reaction mixture could be refluxed for longer period of time so that more reactants are converted into products, and hence a sufficient heating period so that equilibrium can be established, and thus a larger yield of the ester can be formed. This would also allow the particles in the reaction to gain sufficient energy to overcome the activation energy barrier for successful collision to produce the ester.…
After recrystallization was completed, resulting crystals were collected by using vacuum filtration. To determine the melting point of acetanilide…
Other factors that contributed to less than 100% yield is the fact that aspirin is slightly water soluble. More product could have possibly been maintained if less water was used. Introduction The purpose of this experiment is to produce aspirin and analyzing it for yield.…
Synthesis ofp-[1-(p-Hydroxyphenyl)-1-(p-Methoxyphenyl)Ethyl]Phenol (HMEP) 0.2 mol of phenol was mixed with the solution containing 100 mL of acetic acid in 200 mL of concentrated hydrochloric acid in 500 mL five necked round bottom flask fitted with anoil bath, thermometer, mechanical stirrer, reflux condenser. The contents of the flask was stirred for a period of 15 min, the solution was heated to 65oC, 0.1 mol ofp-methoxyacetophenone was introduced into a dropwise to the solution for about 6 h. Then the mixture was transferred into 30 mL boiling water containing 2N KOH. The solid product was filtered and acidified with dilute sulphuric acid, then washed with distilled water and dried at 65oC for 12 h. Recrystallization from benzene-aetonewater system gavecrystals. Yield: 82-92 %.…
Levofloxacin cocrystals were prepared by solvent evaporation method. The drug and co formers, stearic acid and sodium saccharin were physically mixed in varying ratios of 1:1, 1:3, 1:5, 1:7 and 1:1 and 2:1 respectively in a glass mortar and the mixtures were dissolved in ethanol as solvent for crystallization. The solvent evaporation was carried in rotary flash evaporator (Laborota 4000, Hiedolph) maintained at 40 ± 2ºC and speed of 30 rpm. The products obtained were dried in a desiccator and the dried levofloxacin - stearic acid (L-ST) co crystals and levofloxacin-sodium saccharin (L-SA) co crystals were sieved using #60 sieve of 250μm size. The cocrystal preparations were sealed in tightly closed containers at room temperature and stored…
Lastly, the product was weighed and tested for purity. The experimented resulted in the production 3.68 g of aspirin crystals which had a little impurity. This report discusses an experiment to study the synthesis of a drug from organic material. The experiment deals with the…
Gastroretentive System of Metformin: Approaches to Effervescent Tablet Sudhanshu K Chakravati1, Javed Khan Pathan1, Sapna Malviya1, Anil Kharia1 Modern Institute of Pharmaceutical Sciences, Indore (MP) ABSTRACT Effervescent tablet generally contains in addition to active ingredients, mixture of acids/acid salts (Citric, Tartaric, Malic acid or any other suitable acid or acid anhydride) and carbonate and hydrogen carbonates (Sodium, Potassium or any other suitable alkali metal carbonate or hydrogen carbonate) which release carbon dioxide when mixed with water.…
The main purpose of this experiment is to purify an impure solid by the technique of recrystallization. This technique involves several steps, selecting an ideal solvent, dissolving the compound in a minimum amount of boiling hot solvent, filtering insoluble impurities while the solution is hot; crystallizing the purified compound, and isolate the pure compound by vacuum filtration . The unknown used in the experiment was #4, which were white crystals. In order to determine the ideal solvent we prepared two test tubes. Test tube #1 containing 0.106g of unknown and 3mL of water, it was well mixed.…