Introduction
Naturally occuring polymer compounds which are formed by linking together several molecules as polysaccharides. One among such biological polymer is chitin and its deacetylated derivative, chitosan have attracted significant interest in research for biomedical, food and various chemical industries. Chitin is monomer of (1→ 4) –linked 2- acetamido-2 deoxy- D-glucose. It is the second most abundant polysaccharide next to cellulose and nitrogen containing compound next to protein on earth. Chitin exists in three crystal forms: α, β and γ respectively. Rhombic α-chitin where its chain arranged in parallel direction is present in the shells of crabs, shrimps and other arthropods. γ- chitin is extracted from microorganisms in combinations of α-chitin and β –chitin. Monoclinic β –chitin is found in squid pen (Susana et al., 2008)
The refuses of the Sea Food Processing Industry have enormous amount of shells of crabs, shrimps and molluscs species. This waste is normally affect the human health and pollute the environment too. They are the primary raw materials for chitin and chitosan production. The extraction of chitin from these hard materials needs chemical process for the removal of Calcium carbonate, protein and some minerals. The shells also contain considerable amount of colour compounds such as carotenoids, astaxanthin etc. The high amount of acid and alkaline is required for the elimination of these compounds by step by step process such as deminieralization (dilute acid medium) deprotenization (an alkaline medium) and decolourization. Squid pen is also a raw material usually treated as waste in squid processing industries and not converted to chitin in industrial level. Due to the presence of low calcium carbonate ...
... middle of paper ...
... nanochitiosan in particle size of 100- 80nm size with spherical shape.
FT-IR spectrophotometer measurements
The chemical composition of β- chitin and chitosan was analysed using FT-IR spectrophotometer. In case of β- chitin, the OH- and CH strectching groups involved with hydrogen bonding was occurred in 3467 and 2880 cm-1 respectively. A single band was observed in 1666 cm-1 of β- chitin, indicating that its amide groups establish hydrogen bonds. The various vibrational modes with CH2 bending and CH3 deformation was found in 1558 and 1378 cm-1. A well defined band at 1467 cm-1 denotes the amind I band. Assymetrical bridge with oxygen stretching and asymmetrical inphase ring stretching vibrational mode was observed in 1157 and 1114cm-1 respectively. CO- strectching mode was observed in 1068, 1031 cm-1 and CH3 wagging along chain clearly revealved in 946 cm-1.
The goal of this two week lab was to examine the stereochemistry of the oxidation-reduction interconversion of 4-tert-butylcyclohexanol and 4-tert-butylcyclohexanone. The purpose of first week was to explore the oxidation of an alcohol to a ketone and see how the reduction of the ketone will affect the stereoselectivity. The purpose of first week is to oxidize the alcohol, 4-tert-butylcyclohexanol, to ketone just so that it can be reduced back into the alcohol to see how OH will react. The purpose of second week was to reduce 4-tert-butylcyclohexanol from first week and determine the effect of the product's diastereoselectivity by performing reduction procedures using sodium borohydride The chemicals for this lab are sodium hypochlorite, 4-tert-butylcyclohexanone
The two diastereomeric products that are made do not separate well by TLC. In order to see the two isomers, it is necessary to convert the products into derivatives. To more easily identify the stereoisomers produced in the reduction of benzil, hydrobenzoin is converted to acetonide by reacting with 2-methoxypropene and acid. The cis and trans isomers of these derivatives have different Rf values on TLC making it possible to identify the stereoisomers that have been prepared. The solution is compared with syn and anti acetonide on two different TLC plates.
This experiment sought to utilize melting point, boiling point, infrared (IR) spectroscopy, and the index of hydrogen deficiency (IHD) to identify the structures of two unknown compounds. To ensure the successful identification of the unknowns, the molecular formula for each compound was found first. What the molecular formula does is that it allows chemists to identify elements present in a compound as well as the quantity of each element. The issue with this is that there are various compounds that share the same molecular compound yet are different in reactivity and connectivity. To resolve this problem, other measures such as finding functional groups based on IR spectroscopy, determining the boiling or melting point of a compound, and identifying the bond/ring structures using IHD are taken.
Amandi Hiyare: Before forming my research question, I had a discussion with my research project coordinator “Lisa Pope” who told me that the Flinders nanotechnology research team has been developing microbial catheters. Then on Monday I had an interview with Professor Joe Shapter who told me that your team was leading this project. So I was wondering whether you would be able to provide me with some detailed information about this innovation?
Since, the expected weight was 50.63 mg the percent yield is 59.3%. A TLC was conducted on this final product and a faint spot of 4-tert-butylcyclohexanone still appeared in lane 3 of the plate; meaning the reaction did not fully go to completion. The Rf values were 0.444, 0.156, and 0.111, where the lowest value is the trans isomer and the highest value is the ketone. This affected the IR spectrum conducted by having a carbonyl group peak at 1715 cm-1 which should not be present if all the product was 4-tert-butylcyclohexanol. However, the IR spectrum still showed peaks at 3292 cm-1 (hydroxyl group), 2939 cm-1 (sp2 carbon bonded to hydrogen) and 2859 cm-1 (sp3 carbon bonded to hydrogen) which support the presence of the alcohol. The accepted melting point of 4-tert-butylcyclohexanol is in the range of 62 – 70˙C (Lab Manual). The two melting point measurements using the Mel-Temp® machine gave ranges of 57 – 61˙C and 58 – 62˙C, which is not exact due to some 4-tert-butylcyclohexanone being present that has a low melting point of around 47 – 50˙C
The IR spectrum that was obtained of the white crystals showed several functional groups present in the molecule. The spectrum shows weak sharp peak at 2865 to 2964 cm-1, which is often associated with C-H, sp3 hybridised, stretching in the molecule, peaks in this region often represent a methyl group or CH2 groups. There are also peaks at 1369 cm-1, which is associated with CH3 stretching. There is also C=O stretching at 1767 cm-1, which is a strong peak due to the large dipole created via the large difference in electronegativity of the carbon and the oxygen atom. An anhydride C-O resonates between 1000 and 1300 cm-1 it is a at least two bands. The peak is present in the 13C NMR at 1269 and 1299 cm-1 it is of medium intensity.
The purpose of this experiment is to determine the absolute configuration of an unknown chiral secondary alcohol using the competing enantioselective conversion (CEC) method. This method uses both R- and S- enantiomers of a chiral acyl-transfer catalyst called homobenzotetramisole (HBTM), in separate parallel reactions, and thin layer chromatography to identify the stereochemistry of the secondary alcohol, whether it be an R- or S- enantiomer. Quantitative analysis was performed using a program called ImageJ after the appropriate picture was taken of the stained TLC plate. The molecular structure of the unknown alcohol was identified using 1H NMR spectroscopy by matching the hydrogens to the corresponding peak.
Squidward Tentacles is an employee at the Krusty Krab. He is a 34 year old male. He resides in Bikini Bottom. His hobbies include playing his clarinet and painting multiple pictures which he has false hope will one day be published in some museum. He has hatred for going to work, and is horrible with customer service. He exhibits a strong desire to fit in with a higher caste than himself. There have been many episodes though where when given the chance to prove himself worthy of a higher caste he will retreat to a safer place like his house. His esteem level seems very low. He never leaves his house other than for work either. He hates being social and that’s very obvious in every action Squidward carries out. He rarely dates and when he does there is never a second date. He is a healthy man of his age. He really doesn’t have many friends. There is his two neighbors Spongebob Squarepants and Patrick Star, they want to be friends with him but Squidward can barely tolerate either of them. When he is sad he usually turns to his music, painting, or bubble baths which he takes very often. His life goal or aspiration is to be a famous artist and musician. He’s a very smart individual but has absolutely horrible social skills.
This suspension was allowed to stand for 10 minutes, before being filtered, washed (water 2 x 10 mL) and air dried. The crude product was recrystallised from ethanol to yield a yellow solid 3. 26% yield (1.83 g); Elemental analysis for C12H17NO4: C: 54.918%, H: 6.704%, N: 5.122% (Theoretical: C: 60.24%, H: 7.16%, N: 5.85%, Loss:26.75%); Mr 239.2 g mol-1; ν/cm-1: 1259.48 (N-C), 1667.41 (C=C), 1688.41 (C=O), 2976.58 (C-H), 3265.02 (N-H); 1H-NMR (400 MHz, CDCl3), δ/ppm: 1.24 and 1.38 (dt, 3H, C-CH3, C12 and C15), 2.51 and 2.56 (ds, 6H, 2 x =C-CH3, C6 and C7), 4.31 (m, 4H, 2 x -CH2-, C11 and C14), 5.3 (s, 1H, N5-H); 13C-{1H}-NMR (400 MHz, CDCl3), δ/cm-1:11.98 (C6 and C7), 14.43 (C12 and C15), 59.50 and 60.29 (C11 and C14), 133.5 (C3), 117.5 (C1), 131.3 (C2), 138.6 (C4), 165.47 (C8 and C9) .
Raman spectroscopy is, besides IR spectroscopy, one of the two spectroscopic methods used for vibrational analysis. Both techniques are used to provide a fingerprint of molecules by generating spectra. The main difference is that IR spectroscopy is based on absorption of photons with a frequency equal to the vibrational frequency of functional groups, whereas Raman spectroscopy is based on inelastic scattering of monochromatic light. (14) Also different selection rules apply on these techniques, meaning the techniques are
Green Packaging: Nano fibres can be constructed from organic corn or lobster shells and are both antimicrobial and biodegradable.
V. Amarnath, D. C. Anthony, K. Amarnath, W. M. Valentine, L. A. Wetterau, D. G. J. Org. Chem. 1991, 56, p. 6924-6931.
Vibrational spectroscopy is a term used to describe the analytical techniques Infrared and Raman spectroscopy. These two techniques are tools used to provide information about the molecular composition, structure and interactions with a sample. Both techniques are non-destructive, qualitative and rapid. They measure the vibrational energy levels that are affiliated with the chemical bonds in a sample. IR and Raman spectra are complementary to each other and provide scientists with images of vibrations from atoms in compounds. Both Infared and Raman spectroscopy provide good results in being able to discriminate between genuine and counterfeit pharmaceutical products (Been et al, 2011). Historically, infra-red spectroscopy has been used much more than Raman spectroscopy, but recent
One of the most important uses of organic compounds is in medicine. All living things have four organic molecules - carbohydrates, proteins, lipids and nucleic acids. Without carbon chains and nucleic acids, DNA would not exist. Enzymes which produce chemica...
At present, the market of the Malaysian fish fermented products remains to fulfill the local demand. As comparison, Thailand is reported to be the largest fish sauce exporter in the world with more than USD $13 million to US, Japan and Australia export annually (Brillantes, 1999 as cited in Sim, Chye, Anton, nd). Sim et al. (nd) proposed that the limitation of the local Malaysian fish sauce producer is due to the long fermentation time, limited technology and skill which cause low quality control of the products.