Synthesis of flavonoids, anthocyanins and anthocynidins: Flavonoids are coloured compounds imparting colours ranging from red, yellow, scarlet, violet, and blue and so on. There are more than 5000 different known flavonoids. Flavonoids are C15 aglycone skeletons in the arrangement C6-C3-C6 with two aromatic rings connected by a three-carbon bridge. Interestingly, this structure originates of two separate biosynthetic pathways. The bridge and one aromatic ring (ring B) is founded by a phenyl¬propanoid unit biosynthesized from p-coumaryl-CoA (refer formation of p-coumaryl CoA from Phe; above).
Note that they all contain 40 carbon atoms and, because of the extensive conjugation, would be expected to be highly colored. Most carotenoids are yellow, red or orange, but some are green, pink and even black. Many of the bright colors found in flower petals are due to the presence of carotenoids (although some are due to anthocyanins). The yellow colors of fall foliage are due primarily to preferential destruction of the green chlorophylls, revealing the carotenoid color. The percentage composition of carotenoids in plants varies with growing conditions.
In this lab, the oxidation of a secondary alcohol was performed and analyzed. An environmentally friendly reagent, sodium hypochlorite, was used to oxidize the alcohol, and an IR spectrum was obtained in order to identify the starting compound and final product. The starting compound could have been one of four alcohols, cyclopentanol, cyclohexanol, 3-heptanol, or 2-heptanol. Since these were the only four initial compounds, the ketone obtained at the end of the experiment could only be one of four products, cyclopentanone, cyclohexanone, 3-heptanone, or 2-heptanone. In order to retrieve one of these ketones, first 1.75g of unknown D was obtained.
However, it dissolved in non-polar solvent toluene and slightly in ethanol, which means naphthalene is non-polar. It has high resistivity in aqueous solution and solid form, and respective melting point. The sample was given as solid with large shiny white crystals. Silicon carbide was classified in this experiment as macromolecular structure. This compound was insoluble at any type of solvent both polar and non-polar.
Beta-carotene is the most nutritionally active carotenoid. Gentle cooking generally improves utilization of beta-carotene in foods. It is best absorbed with fat, and further processed as a beta-carotene-lipoprotein-complex. In the gastrointestinal tract beta-carotene is metabolized to retinal by oxidative opening of a double bound by the enzyme 15,15’-Dioxygenase in intestinal cells or liver. Retinal is subsequently reduced to retinol; that is, vitamin A. Bilic acids work as detergents and help stimulate the metabolism of carotenoids.
The great variety of species over which these compounds are found has grown as detection techniques have improved. Tannins are high molecular weight, water-soluble polyphenols that form reversible complexes with proteins through pH-dependent hydrogen bonding and hydrophobic interactions. Hydrolysable tannins (HT) contain a carbohydrate core esterified with gallic or hexa-hydroxyl-diphenic acids. Binding of HT to abomasal mucosal proteins causes lesions that result in diarrhea or constipation. Hydrolytic products of HT are absorbed from the small intestine; disrupt liver and kidney function, and cause photosensitization and dehydration.
Tannins. An organic substance present in some galls, barks, and other plant tissues, consisting of derivatives of gallic acid, used in leather production and ink manufacture. Triterpenoids. They are a type of terpene containing 30 carbon atoms. Triterpenes are assembled from a five-carbon isoprene unit through the cytosolic mevalonate pathway to make a thirty-carbon
Moreover, among the 50 provitamin, there are 3 carotenoids that are considered as the most significant precursors of vitamin A in humans which are b-cryptoxanthin, a-carotene and b-carotene that are converted and metabolized to vitamin A in the body. The importance of these provitamin carotenoids is that they serve as a source of vitamin A which is needed for normal growth and development, immune system function and vision. Carotenoids as antioxidant Carotenoids have the ability to function as antioxidants and promote oxidative stress resistance. In plants, antioxidant activity of carotenoids is based on their singlet oxygen quenching properties. In the human, carotenoids are part of antioxidant defense system that work in two ways either by singlet oxygen quenching properties as in plants or through scavenging oxidizing free radicals via giving the free radical its missing electron instead of taking it from other macromolecules.
The aim of this essay is to explain the chemical and physical properties of carbon allotropes which are graphite, diamond, buckminsterfullerene, amorphous carbon and their applications in industry. Allotropes are element which is made up of the same material and have different ways of bonding to form different structure (NOVA 1995)(KALDOR 1988).There are four types of carbon allotropes which are diamond , graphite ,amorphous carbon and buckminsterfullerene (Evan, 2001) . Graphite is a slippery, black material which has high melting point and is insoluble in water. Therefore, graphite electrodes are used in electrochemical industries where corrosive gases are produced and used in high temperature electric furnace (Graphite, Encarta online, 2001). Moreover, diamonds are transparent, hard and lustrous