Animals organic chemicals from

Organic chemicals from animal and vegetable oils and fats... 

Animal bones can be carbonized to produce adsorbent materials which have only meso- and macropores and surface areas around 100 m /g. The pore development activation step used with activated carbons is dispensed with. The surface is carbon and hydroxyl apatite in roughly equal proportions and this dual nature means that bone charcoals can be used to adsorb metals as well as organic chemicals from aqueous systems. Decolourizing sugar syrup is another application. 

In 1933, R. Kuhn and his co-workers first isolated riboflavin from eggs in a pure, crystalline state (1), named it ovoflavin, and deterrnined its function as a vitamin (2). At the same time, impure crystalline preparations of riboflavin were isolated from whey and named lyochrome and, later, lactoflavin. Soon thereafter, P. Karrer and his co-workers isolated riboflavin from a wide variety of animal organs and vegetable sources and named it hepatoflavin (3). Ovoflavin from egg, lactoflavin from milk, and hepatoflavin from Hver were aU. subsequently identified as riboflavin. The discovery of the yeUow en2yme by Warburg and Christian in 1932 and their description of lumiflavin (4), a photochemical degradation product of riboflavin, were of great use for the elucidation of the chemical stmcture of riboflavin by Kuhn and his co-workers (5). The stmcture was confirmed in 1935 by the synthesis by Karrer and his co-workers (6), and Kuhn and his co-workers (7). 

All organic chemicals are, by definition, based on chemicals derived from living matter. Thus, the ten highest-volume commercial organic chemicals are all made from starting materials obtained from petroleum (oil) and natural gas, which are believed to have been formed by the microbial decomposition of ancient marine plants and animals. 

In contrast to the other large cats, the urine of the cheetah, A. jubatus, is practically odorless to the human nose. An analysis of the organic material from cheetah urine showed that diglycerides, triglycerides, and free sterols are possibly present in the urine and that it contains some of the C2-C8 fatty acids [95], while aldehydes and ketones that are prominent in tiger and leopard urine [96] are absent from cheetah urine. A recent study [97] of the chemical composition of the urine of cheetah in their natural habitat and in captivity has shown that volatile hydrocarbons, aldehydes, saturated and unsaturated cyclic and acyclic ketones, carboxylic acids and short-chain ethers are compound classes represented in minute quantities by more than one member in the urine of this animal. Traces of 2-acetylfuran, acetaldehyde diethyl acetal, ethyl acetate, dimethyl sulfone, formanilide, and larger quantities of urea and elemental sulfur were also present in the urine of this animal. Sulfur was found in all the urine samples collected from male cheetah in captivity in South Africa and from wild cheetah in Namibia. Only one organosulfur compound, dimethyl disulfide, is present in the urine at such a low concentration that it is not detectable by humans [97]. 

Other important natural sources of organic chemicals are the so-called fossil fuels - natural gas, petroleum, and coal - all deposited in the earth from the decay of plant and animal remains, and containing thousands of degradation products. Most of these are simple compounds containing only carbon and hydrogen (technically and even reasonably known as hydrocarbons). Natural gas is relatively simple... 

In the late nineteenth century and up to World War II coal was the major starting material for the organic chemical industry. When coal is heated in the absence of oxygen, coke and volatile by-products called coal tars are created. All sorts of organic chemicals can be isolated from coal tar - benzene, toluene, xylenes, ethylbenzene, naphthalene, creosotes, and many others (including Hofmann and Perkin s aniline). The organic chemical industry also draws upon other natural products, such as animal fats and vegetable oils, and wood by-products. 

To deterniine the risks in the area of human health (workers, consumers, including the absorption of chemicals from the environment) the concentration of a substance is ascertained for so-called end points in the human body (organs or biological systems). The measured or calculated concentration (exposure level) is compared with the NOAEL (No Observed Adverse Effect Level). The NOAEL is the highest concentration at which no more effect is observed (usually in animal testing), i.e. there is no visible or measurable effect. If such a levef cannot be detected, the LOAEL (Lowest Observed Adverse Effect Level) can be applied instead. This is the value at which the effect first becomes visible or measurable with an increasing dose. 

A forerunner to this approach was published in 1963 when organic chemicals accumulated from water by carbon adsorption and soxhlet extraction were found to cause tumors in laboratory animals W. However, the two-year period for completion of the animal tests of the accumulated mixture was a serious drawback. 

Metabolism studies in dogs and rats with radiolabeled tetracycline showed that with the exception of metal-chelate formation, tetracycline was chemically unaltered by the rat (247). Organ extracts from dosed animals were not found to contain metabolic products of tetracycline. Dog urine also contained unchanged drug, indicating that metabolic transformation of tetracycline had not occurred. 

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