Organic acids propionic acid

Because of the insolubility of cellulose it is not possible to carry out uniform esterification with the lower organic acids (acetic acid, propionic acid etc.) and in those cases where incompletely substituted derivatives are required a two-stage reaction is employed. This involves total esterification in a medium in... 

Organic Acids Acetic Acid Butyric Acid Formic Acid Propionic Acid Acrylic Acid (inhibited)... 

The intrinsic viscosity of poly(L-proline) is studied as a function of molecular weight and temperature In five commonly used solvents water, trifluoroethanol, acetic acid, propionic acid, and benzyl alcohol. The characteristic ratio is 14 in water and 18-20 in the organic solvents at 303 K, and d (in 0) / d T is negative. The theoretical rotational potential function obtained by Hopfinger and Walton for u-prolyl-L-prolyl-t-prolyl-t-proline J. Macromol. Scl. Phys. 1969, 3, 171 correctly predicts the characteristic ratio at 303 K but predicts the wrong sign for tfiln < >0) IdT. 

Xiao-Hua Yang et al. [103] determined nanomolar concentrations of individual low molecular weight-carboxylic acids (and amines) in seawater. Diffusion of the acids across a hydrophobic membrane was used to concentrate and separate carboxylic acids from inorganic salts and most other organic compounds prior to the application of ion chromatography. Acetic acid, propionic acid, butyric acid-1, butyric acid-2, valeric and pyruvic acid, acrylic acid and benzoic acid were all found in reasonable concentrations in seawater. 

Figure 2a shows the separation of DNP-amino acids using three spacer acids (i.e., acetic acid, propionic acid, and n-butyric acid) in the stationary phase [2]. Hydrophilic DNP-glutamic acid is eluted between acetic and propionic acids DNP-alanine between propionic and n-butyric acids, and hydrophobic DNP-leucine after n-hu-tyric acid. The method can be effectively applied for the separation and concentration of a small amount of organic ions present in a large volume of the sample solution. However, the most useful application has been... 

The effects of added water on G(NH3) and G(propionic) from the sodium salt of acetylalanine are summarized in Figure 3. The ammonia yield which as we have noted is derived from a number of reaction modes shows but a small decrease, AG(NH3), — 1, as the acetylalanine concentration is decreased to 1M. And, even more striking is the fact that the yield of the major organic product, propionic acid, is essentially independent of acetylalanine concentration over the entire range of Figure 3. Our tentative conclusion is then that cleavage of the N—C bond to yield propionic acid does not arise in the main from the positive-ion chemistry of Reactions 16, 16a, 18, and 18a. 

For the biosynthesis of cell components a microorganism must be supplied with appropriate low molecular weight compounds such as sugars, organic acids, amino acids etc. Many of 2-, 3-, 4- and 5-carbon compounds are formed in catabolic reactions. In propionic acid bacteria these reactions comprise the propionic acid fermentation, TCA cycle and hexose monophosphate shunt. The latter supplies the cell with erythrose-phosphate, ribose-5-phosphate and reducing equivalents (NADPH) needed for many syntheses. Erythrose-4-phosphate is used in the formation of aromatic amino acids phenylalanine, tryptophane, tyrosine. Ribose-5-phosphate is incorporated into nucleic acids. The pentose cycle and propionic acid fermentation, as mentioned before, have a number of common precursors and enzymes. The inclusion of common precursors into one or another pathway is regulated by the level of ATP (Labory, 1970), and this regulation in fact determines the ratio of catabolic and anabolic processes in the cell. 

Organic Acids, Sulfonic Acids and Propionic Acid. The electrical conductivity of PDDT is about four to five orders of magnitude lower than in the case of iodine, but the electrical conductivity of the films is environmentally more stable. In addition, the dopant 4-dodecylbenzenesulfonic acid can act as a plasticizer for the PT film [273]. 1-Naphthalenesulfonic, ethylenebenzenesulfonic, methyl-ethylsulfonic, butanesulfonic, and pentafluoropropionic acids can be used for doping of POT and PDT [189]. 

Antimicrobial releasing Organic acids (benzoic acid, sorbic acid, propionic acid, lactic acid), silver salts, sulfur and its compounds, bacteriocins (nisin and lacticin), zeolites, chlorine dioxide, grape seed extracts, lemon seed extracts, spice extracts (thymol, p-cymene, and cinnamalde-hyde), enzymes (peroxidase and lysozyme), chitosan, chelating agents (EDTA), Plant essential oils... 

One of the limitations to the wider use of calcium chloride in reinforced concrete is that, if present in larger amounts, it promotes corrosion of the reinforcement unless suitable precautions are taken. There is, hence, a continuing attempt to find an alternative to calcium chloride, one equally effective and economical, but without its limitations. A number of organic and inorganic compounds including aluminates, sulfates, formates, thiosulfates, nitrates, silicates, alkali hydroxides, carbonates, halides, nitrites, calcium salts of acetic acid, propionic acid, butyric acid, oxalic acid and lactic acid, urea, glyoxal, triethanolamine, and formaldehyde have been suggested. However, practical experience and research on most of these admixtures is limited. 

It IS hard to find a class of compounds in which the common names of its members have influenced organic nomenclature more than carboxylic acids Not only are the common names of carboxylic acids themselves abundant and widely used but the names of many other compounds are derived from them Benzene took its name from benzoic acid and propane from propionic acid not the other way around The name butane comes from butyric acid present m rancid butter The common names of most aldehydes are derived from the common names of carboxylic acids—valeraldehyde from valeric acid for exam pie Many carboxylic acids are better known by common names than by their systematic ones and the framers of the lUPAC rules have taken a liberal view toward accepting these common names as permissible alternatives to the systematic ones Table 19 1 lists both common and systematic names for a number of important carboxylic acids... 

By-products include propylene dibromide, bis-(bromopropyl) ether, propylene glycol, and propionic acid. Bromide losses are to the brominated organics and bromate formation. Current efficiency is a function of ceU design and losses to bromate. Energy consumption decreases with an increase in electrolyte concentration and a decrease in current density. Space—time yield increases with current density. See Table 5 for performance data (see... 

With Unsaturated Compounds. The reaction of unsaturated organic compounds with carbon monoxide and molecules containing an active hydrogen atom leads to a variety of interesting organic products. The hydroformylation reaction is the most important member of this class of reactions. When the hydroformylation reaction of ethylene takes place in an aqueous medium, diethyl ketone [96-22-0] is obtained as the principal product instead of propionaldehyde [123-38-6] (59). Ethylene, carbon monoxide, and water also yield propionic acid [79-09-4] under mild conditions (448—468 K and 3—7 MPa or 30—70 atm) using cobalt or rhodium catalysts containing bromide or iodide (60,61). 

Organic acids may inhibit growth when present in the undissociated form because of their abiHty to change the pH inside the ceU. The most efficient are benzoic acid and sorbic acid, but formic, acetic, and propionic acid also have this effect. The parabens, ie, -hydroxy benzoic acid esters, are also used because of their antimicrobial effect over a broad pH range. 

The general plan of Organic Syntheses has been discussed in the prefaces of the previous volumes. In this volume are published two distinctly different methods of preparation for each of two compounds. The directions for producing /3-chloro-propionic acid first from acrolein and second from trimethylene chlorohydrin, and for producing trimethylacetic acid first from terJ-butyl chloride and second from pinacolone, have been included. This has been deemed advisable since in some countries one raw material is more readily available than the other. 

Organic acids (acetic, butyric, propionic and citric acids)... 

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