Conclusion The isolation of β-carotene from lycopene via column chromatography was accomplished, but results were inconsistent. Many students were unable to isolate the first elution compound, β-carotene; however, lycopene isolation was very obtainable; due to the structural similarity of these two molecules, it was intuitive that a separation would be difficult. UV/VIS and TLC analysis of the compounds confirmed that it is possible to isolate β-carotene from lycopene, due to differences in dipole moments of these chemicals. In future experiments, it is suggested to use a mobile phase less polar than 15% ethyl acetate and 85% hexanes such as 5% ethyl acetate and 95% hexanes, for this would have potential to create a better separation. It was
The image above is our chromatogram, you can see at the top the orange bands of a carotene, next are the bands of xanthophylls which are yellow. The next light green bands directly bellow the yellow is chlorophyll a, the darker green bands are chlorophyll b. In order to test absorbance of the chlorophylls they were cut out of this chromatogram submerged into acetone and then used to get an absorption spectrum as seen below.
There are millions of different organic compounds. Most of them are found in mixtures and in order to achieve a pure form they need to be separated, isolated, and purified. However, there are endless numbers of possible mixtures, which make it impossible to have a pre-designed procedure for every mixture. So chemists often have to make their own procedures. The purpose of this experiment was to prepare the student to the real world by them designing their own procedure which will help them understand the techniques of separation and purification better. The goal was to extract two of the components of the
Lycopene and β-carotene are separated using thin layer chromatography (TLC). A mixture of tomato paste containing dissolved lycopene and β-carotene is first spotted on a TLC plate. The technique uses a stationary phase layer, on which the substances stick, and a mobile phase, which migrates upwards the plate and carries the components of the mixture with itself (Chemguide). Depending on their respective polarity, lycopene and β-carotene stick more or less to the stationary phase and so they migrate up the TLC plate at different rates (Chemguide). Thus, as the chromatography is completed, the two components will appear as distinct dots at different heights on the plate. Lycopene has a bright orange color, whereas β-carotene is light yellow.
Abstract: The purpose of this lab is to separate and identify pigments and other molecules within plant cells by a process called chromatography. We will also be measuring the rate of photosynthesis in isolated chloroplasts. Beta carotene, the most abundant carotene in plants, is carried along near the solvent front because it is very soluble in the solvent being used and because it forms no hydrogen bonds with cellulose. Xanthophyll is found further from the solvent font because it is less soluble in the solvent and has been slowed down by hydrogen bonding to the cellulose. Chlorophylls contain oxygen and nitrogen and are bound more tightly to the paper than the other pigments.
1. Benedict’s solution is added to white grape juice and heated. The color changes from blue to orange. Based on this result, what biological molecules are
In the beginning of this experiment, our TA added water, salt, and 75/25 hexane/acetone to spinach leaves to a blender and blended the mixture to assume equal amounts for each group and to avoid erros if each student had to do the blending. The addition of the water to the mixture allowed the it to separate into a distinct organic layer after being run in a centrifuge, which was available to be collected at the top of the centrifuge. Salt reduces solubility, which will force the organic parts of the mixture (the desired pigments for example) to separate into the organic layer at the top. Lastly, 75/25 hexane/acetone is added because this is a moderately polar solvent and will useful for both the non-polar and polar pigments present within the spinach leaves. A mixed solution of hexanes and acetone must be used because acetone is very polar, while hexane in very non-polar, and the spinach leaves contain both non-polar and polar pigments in them that are important in the extraction and for further analysis. The mixture was placed in the centrifuge so the solids in the mixture (mostly cellulose) could be separated from the liquids into separate distinct layers for further extraction and testing. In the tube, the organic substances separated into the top layer, whereas the water layer remains at the bottom of the tube below the solid layer made up of mainly cellulose.
Then the mixture with a few boiling chips were added in a reflux condenser for thirty minutes. After this period the hot chloroform solution was filtered through a Hirsch funnel, and three more washes of the bark were performed with additional hot chloroform, (3X10ml). In the last step for the purification of butelin the previous chloroform solution was passed over a microscale column of silica gel3 (9cm) and the clean product was collected in a 250ml RBF. Before the rearrangement reaction 10ml of the clean product was collected for evaporation using a rotary evaporator, for the determining of NMR spectrum. Moreover two drops of this product was used as a sample for TLC chromatography. The second step of this experiment includes the rearrangement of betulin to alloetulin. In this stage 120mg of p-toluenesulfonic acid were dissolved in the remaining chloroform solution of betulin. Then 3 drops of water and one small boiling chip were added in the solution and a reflux condenser was used for 60 minutes. After this period the chloroform solution was cooled for 15mins. Thereafter the solution was washed three times with 5% sodium bicarbonate and sodium sulfate was used to dry the chloroform solution. In the end, filtration of the drying agent and rotary evaporation of the chloroform solution, gave the alloebtulin. Finally two more drops of this product was used in the same sample of butelin
Given that taxol and vinblastine disrupt the progression of mitosis and that chromosome condensation is a critical process in mitosis, it is likely that these drugs have an effect on this critical process14. As such, it is intuitive to investigate the effects of drugs on the manifestation of this process, which is the integrity of the chromosomes. Moreover, as compromising the integrity of chromosome reduces cell viability, it is very probable that the chromosomal integrity was altered during the prolonged mitotic delay, which leads to the eventual cell
The carotenoids are known fat-soluble pigments that are prevalent in numerous fruits and vegetables. Lycopene, the natural carotenoid in tomatoes and tomato products, is the most potent antioxidant among the other natural antioxidants such as α-tocopherol, α-carotene, β- cryptoxanthin, and β-carotene. Recently, lycopene has become focus of great interest due to its highly efficient antioxidant scavenging activity. Recent studies have suggested a protective role for lycopene in the prevention of lipid oxidation (Viuda-Martos, Sanchez-Zapata, Sayas-Barberá, Sendra, Pérez-Álvarez & Fernández-López, 2013).
The purpose of this experiment was to take spinach leaves and extract the chlorophyll and carotenoid pigments by using acetone as the solvent. The chlorophyll and carotenoid pigments were extracted by using column chromography and alumina was used as the solvent. Solvents of different polarities were used, starting with the least polar, to extract the certain components from the leaves. They were then analyzed by using thin- layer chromatography.
The reflex measured in the aplysia was the gill withdrawal reflex. We know that the animal has learned the longer the gill and siphon are retracted. The response of the aplysia to the stimulus after it has been paired with a shock is that it has learned that there is danger in its environment therefore it is on high alert and remains retracted. Its reflex last four times longer than a naïve animal. The response at the synapse is different after short-term exposure to a shock because the synapse between the sensory neurons and motor neurons gets stronger. The neurons begin to communicate differently because they temporally send stronger chemical signals and receive more signals that correspond to short term memory. If the shocks are given over
2014). Spirulina is one of the main sources of natural phycocyanin, which is used as a natural color in food products like chewing gums, candies, dairy products, jellies, ice creams, soft drinks and used as biochemical tracer in immunoassays(Gouveia et al. 2008). ß-carotene represents 70% of total carotenoids present in Spirulina which is equivalent to 53% more retinol equivalent than the amount present in carrots(Dey and Rathod
Effect of blending of Crude Palm oil with sunflower and groundnut oil on proximate composition, β-carotene and total carotenoids contents of samosa and cutlet
You may have heard that tomatoes and processed tomato products such as tomato sauce, tomato paste, and canned tomatoes protect against some types of cancer. The cancer-preventing properties of tomato products have been attributed to lycopene. It is a bright red pigment found in tomatoes and other red fruits and is the cause of their red colour. Unlike other fruits and vegetables, where nutritional content such as vitamin C is diminished upon cooking, processing of tomatoes increases the concentration of lycopene. Lycopene concentration in tomato paste is four times more than in fresh tomatoes. This is because lycopene is insoluble in water and is tightly bound to vegetable fiber. Thus, processed tomato products such as pasteurized tomato juice,
Extraction is a process by which substances and active constituents are separated from the original matrix, extraction process depends on many physical and chemical characteristics. Extraction is divided into two types liquid phase extraction and solid phase extraction depending on the physical phase of extraction agent(Rezaee et al., 2006). In our study, we have adopted liquid phase extraction for several reasons. Firstly, simple, inexpensive, relatively precise and wide range methods for separation, identification, and quantification of drugs, poisons, and herbal medicine. Secondly, An equilibrium distribution is established by the ratio between two phases will be influenced by the choice of the extracting solvent, the pH value of the aqueous phase and the ratio of the volumes of the organic to aqueous phases (Ahadi et al., 2011).