Acetic acid from natural sources

Using What Nature Provided - Acetic Acid from Natural Sources. 

Acetic acid (qv) can be produced synthetically (methanol carbonylation, acetaldehyde oxidation, butane/naphtha oxidation) or from natural sources (5). Oxygen is added to propylene to make acrolein, which is further oxidized to acryHc acid (see Acrylic acid and derivatives). An alternative method adds carbon monoxide and/or water to acetylene (6). Benzoic acid (qv) is made by oxidizing toluene in the presence of a cobalt catalyst (7). 

Many carboxylic acids were first isolated from natural sources and were given names based on their origin. Fonnic acid (Latin formica, meaning ant ) was obtained by distilling ants. Since ancient times acetic acid (Latin acetum, for vinegar ) has been known to be present in wine that has turned sour. Butyric acid (Latin butyrum, meaning butter ) contributes to the odor of both rancid butter and ginkgo benies, and lactic acid (Latin lac, for milk ) has been isolated from sour milk. 

A solution of acetic acid formed in this manner is familiar as vinegar. Acids are also obtained from natural sources. A few examples are listed in Table 21-7. 

The reagent is suggested by W. Triebs for the isolation of volatile ketones from natural sources. Condensation with a ketone is conducted by refluxing with the reagent in aqueous alcohol buffered with sodium acetate. The reaction mixture is extracted with ether for removal of nonketonic material, the aqueous solution is treated with hydrochloric acid, and the ketone liberated is removed by steam distillation. 

As described in Section il, cationic peptides are very widely distributed in nature. Recovery from these sources involves a wide range of methods. One effective procedure is extraction with 30% acetic acid, which tends to solubilize cationic peptides and precipitate many globular proteins. This is usually followed by a variety of chroinatogra ic procedures often including reverse phase HPLC or FPLC as the final step in purification. However, purification from natural sources is rarely a practical ahemarive for commercial purposes, since yields tend to be relatively low. For example, a single rabbit will permit the recovery of only 200 mg of rabbit defensins. The one exception is the production of cationic lantibiotic peptides such as nisin from bacteria and commercial production of nisin by fermentation of Lnctococcus beds (see Chapter 15). 

Intact sensing structures (chemoreceptors) from natural sources provide an alternative to binding proteins for a range of small molecules. Crab antennules from the blue crab Calinectes sapidus are sensitive to amino acids and display some selectivity, e.g., the antennules contain a receptor for glutamate which is unresponsive to other amino acids such as glycine, alanine, proline, and taurine (26). Olfactory structures in other species offer selectivity for additional types of molecule which act as pheromones, e.g. the male moth Bombyx mori has specific receptors for the female sex attractant bombykol, and Antherea polyphemus has receptors for E6, Zll-hexadecadienyl acetate and E6, Zll-hexadecadienal. 

Biodegradation indicates degradation of a polymer in natural environment. This implies loss of mechanical properties, changing in the chemical structure, and into other eco-friendly compounds (Jamshidian et al. 2010). Degradable polymers from natural sources (such as lignin, cellulose acetate, starch, polylactic acid (PLA), polyhydroxylaUcanoates, polyhydroxylbutyrate (PHB)), and some synthetic sources (polyvinyl alcohol, modified polyolefins, etc.) are classified as biopolymers (John and Thomas 2008). It is noticeable that the nanocomposite from nonrenewable synthetic sources is neither wholly degradable nor renewable. 

Today, urea, acetic acid, and many other organic chemicals are produced in huge quantities. Organic chemists can synthesize complex drug molecules, such as penicillin and taxol, which were once available only from natural sources. Using methods of organic synthesis, chemists can also prepare completely new drugs, polymers, flavors, and dyes that are not present in nature. 

Also obtained by reaction of 3,4-dihydioxyphenacyl chloride and a-N-acetyllysine in 15% potassium borate and r.L overnight, then adding acetic acid to adjust pH to 5 [6140], Isolation from natural sources... 

Dehydration of the tertiary alcohol (290) led to a miicture of approximately equal amounts of the A - and A -isomers (293) and (294) when it was oxidized with osmium tetroxide, all four theoretically possible isomers of the cis-diols (292) and (298) were obtained. At the same time, both in the case of the 16,17-diols (292) and in the case of the 17,17a-diols (298) the amount of the o -isomer was the greater. The cleavage of the first pair of diols (292) with periodic acid led to the ketoaldehyde (295), which, on being boiled in xylene with triethylammonium acetate, cyclized to form dl-5a-A -pregnen-3/S-ol-20-one acetate (296), identical in respect of its IR and UV spectra with the d-enantiomer obtained from natural sources. By a similar series of reactions, the second pair of diols (298) gave the keto-acetate (297) with an acetyl group at Cjg, isomeric with (296) [648, 649,... 

Vapors emitted from the materials of closed storage and exhibit cases have been a frequent source of pollution problems. Oak wood, which in the past was often used for the constmction of such cases, emits a significant amount of organic acid vapors, including formic and acetic acids, which have caused corrosion of metal objects, as well as shell and mineral specimens in natural history collections. Plywood and particle board, especially those with a urea—formaldehyde adhesive, similarly often emit appreciable amounts of corrosive vapors. Sealing of these materials has proven to be not sufficiently rehable to prevent the problem, and generally thek use for these purposes is not considered acceptable practice. 

Carboxylic acids having 6—24 carbon atoms are commonly known as fatty acids. Shorter-chain acids, such as formic, acetic, and propionic acid, are not classified as fatty acids and are produced synthetically from petroleum sources (see Acetic acid Formic acid and derivatives Oxo process). Fatty acids are produced primarily from natural fats and oils through a series of unit operations. Clay bleaching and acid washing are sometimes also included with the above operations in the manufacture of fatty acids for the removal of impurities prior to subsequent processing. 

This chapter lists some representative examples of biochemicals and their origins, a brief indication of key techniques used in their purification, and literature references where further details may be found. Simpler low molecular weight compounds, particularly those that may have been prepared by chemical syntheses, e.g. acetic acid, glycine, will be found in Chapter 4. Only a small number of enzymes and proteins are included because of space limitations. The purification of some of the ones that have been included has been described only briefly. The reader is referred to comprehensive texts such as the Methods Enzymol (Academic Press) series which currently runs to more than 344 volumes and The Enzymes (3rd Edn, Academic Press) which runs to 22 volumes for methods of preparation and purification of proteins and enzymes. Leading referenees on proteins will be found in Advances in Protein Chemistry (59 volumes. Academic Press) and on enzymes will be found in Advances in Enzymology (72 volumes, then became Advances in Enzymology and Related Area of Molecular Biology, J Wiley Sons). The Annual Review of Biochemistry (Annual Review Inc. Patio Alto California) also is an excellent source of key references to the up-to-date information on known and new natural compounds, from small molecules, e.g. enzyme cofactors to proteins and nucleic acids. 

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