Malic acid application

Important applications for titanium have been developed in processes involving acetic acid, malic acid, amines, urea, terephthalic acid, vinyl acetate, and ethylene dichloride. Some of these represent large scale use of the material in the form of pipework, heat exchangers, pumps, valves, and vessels of solid, loose lined, or explosion clad construction. In many of these the requirement for titanium is because of corrosion problems arising from the organic chemicals in the process, the use of seawater or polluted cooling waters, or from complex aggressive catalysts in the reaction. 

Poly-j3-malate is readily degraded completely to L-malic acid under both acid and base conditions [108], and it can also be hydrolyzed by enzymes within the cell [105,106]. Recently, several bacteria were isolated which were able to utilize poly-/i-malate as sole carbon source for growth [109]. Because the polymer is biodegradable and bioadsorbable, it is of considerable interest for pharmaceutical applications, especially in controlled-release drug delivery systems [97,98]. Chemical routes to poly-/ -malate are expected to provide materials with various properties [110]. 

Vert M (1998) Chemical routes to poly( P-malic acid) and potential applications to this water-soluble bioresorbable poly(P-hydroxy alkanoate). Polym Degrad Stab 59 169-175... 

Before the availability of artificial fertilizers in the mid-19th century, farms were traditionally organic, with recycling of animal waste, and perhaps with the application of lime on acid soils. Agricultural chemical analysis may have begun with Carl Wilhelm Scheele (1742-1786), the Swedish pharmacist who isolated citric acid from lemons and gooseberries and malic acid from apples. In France, Nicolas Theodore de Saussure (1767-1845) studied the mineral composition of plant ash, and in Britain, Sir Humphrey Davy... 

Economic Aspects. Malic acid is manufactured in over 10 countries. The production is primarily used for food i26.6 5) and beverages (54.7. f i however, some industrial applications United States have been stable and are as noted in parentheses). 

Maleic anhydride CAS. 108-3I-6. til, maleic acid [CAS 110-16-7]. (2), and I umarie acid [CAS 110-17-81. i3) are multifunctional chemical intermediates that lind applications in nearly every Held id industrial chemistry. Each molecule contains two acid carbonyl groups and a double bond in the u. position. Maleic anhydride and maleic acid are important raw materials used in the manufacture of phthalic-type alkyd and polyester resins, surface coatings, lubricant additives, plasticizers. copolymers, and agricultural chemicals [see Alkyd Resins Polymers, and Lubricant). Both chemicals derive their common names from naturally occurring malic acid. 

If a method similar to Dionex application no. 123 is used, both organic acids and anions can be separated on the AS-11 column (Figure 10.8) (Anon, n.d.e). In fact, care has to be taken with this method as nitrate and malate ions elute very close to each other under these conditions. This can be a particular issue if the column is not operating well and there is a need to determine the level of nitrate in juices which contain high levels of malic acid. 

In the synthesis (Expt 8.34), formylacetic acid is formed in situ by the action of a concentrated sulphuric acid-fuming sulphuric acid mixture on malic acid (H02OCH0H CH2 C02H). This a-hydroxydicarboxylic acid undergoes decarbonylation and dehydration under these conditions before the acid-catalysed self-condensation of formylacetic acid. The cyclisation step is generally applicable to / -keto esters. 

Belafi-Bako, K., Nemestothy, N., and Gubicza, L. 2004. A study on applications of membrane techniques in bioconversion of fumaric acid to L-malic acid. Desalination 162, 301-306. 

Other important applications in the food industry running at a large scale are the production of L-aspartic add with Escherichia coli entrapped in polyacrilamides [6], the immobilization of thermolysin for the production of aspartame [14], The production of L-alanine by Tanabe Seiyaku [7], the production of frudose concen-centrated syrup [3], the production of L-malic acid by the use of Brevibacterium ammoniagenens immobilized in polyacrilamide by entrapment immobilization methods [11] and L-aminoacids production by immobilized aminoacylase [5],... 

Again, the hydroxy acid malic acid is available by a wide variety of methods, including fermentation,45 but it has not found a large-scale application as a building block. 

By application of the CIP rules the order of priority of the atoms directly attached to the chirality centre is O > C(0,0,(0)) > C(C,H,H) > H. The atom or group of lowest priority, hydrogen in this case, is already oriented away from the observer. Therefore the sequence of the remaining three groups can be directly deduced from the formula, and these are easily seen to be arranged in a counter-clockwise sense to the observer. It therefore follows that the formula represents (S)-2-hydroxysuccinic acid (formerly known as L-malic acid). The compound is produced in the citric acid cycle from fumaric acid by fumarate-hydratase (fumarase). 

Subsequently, as an application of this method, D-ribo-C18-phytosphingosine has been prepared stereoselectively from (S)-malic acid dimethyl ester 50. The electrophilic animating reaction with DTBAD proceeded with 62 % yield and the anti a-hydrazino P-hydroxy ester 51 was obtained as the major diastereomer (anti syn = 67 33). After separation of the two isomers, the synthesis of the enan- ... 

Producers of acidulants came to food applications through chemistry or biochemistry. Malic acid is produced by Denka, now owned by Mobay, in the United States and by Croda in England. Like fumaric acid, it is a derivative of maleic anhydride production. The... 

Similar to fumaric acid, L-malic acid is also a naturally occurring four-carbon dicarboxyhc acid and an intermediate in the TCA cycle. It has been used in many food products, primarily as an acidulant. L-Malic acid is compatible with all sugars with low hygroscopicity and good solubihty. In addition, it has therapeutic value for the treatment of hyperammoemia and liver dysfunction and as a component for amino acid infusion. L-Malic acid has been the subject of interest because of its increased application in the food industry as a citric acid replacement and its potential use as a raw material for the manufacture of biodegradable polymers. 

Malonic Acid, CH2(COOH)2, is so-called because it was first obtained as the result of the oxidation of malic acid. The acid is of particular interest, as many important compounds can be readily prepared as the result of reactions between its esters and other substances. The so-called malonic ester synthesis will be described later (166). Malonic acid crystallizes from water in laminae which melt at 133°-134°, with partial decomposition. It can be prepared by a reaction which illustrates clearly the application of a general method emphasized in the case of acetic acid. The relation between acetic acid and malonic acid is shown by the formulas,—... 

Borane reduces esters very slowly and ketones or aldehydes are selectively reduced in the presence of esters. The most widely used application of borane is for the selective reduction of carboxylic acids, even in the presence of halides, esters, nitriles, and ketones.200 since LiAlH4 reduces both acids and esters and NaBH4 does not reduce acids (and often reduces esters with difficulty), borane is the reagent of choice for selective reduction of carboxylic acids in the presence of an ester group. The reduction occurs without racemization of adjacent chiral centers, as in the borane reduction of (-)-malic acid to generate (5)-l,2,4-butanetriol in 92% yield.201 Seki and Kondo s reduction of the acid moiety in 173 to alcohol 174 (in a synthesis of orally active carbapenams), without reduction of the benzylthio or ester groups also demonstrates this selectivity.202 Borane can reduce imides to give an amine.203 Borane also reduces epoxides at the less hindered carbon when mixed with catalytic amounts of sodium borohydride.204... 

Malic acid, although useful itself in many synthetic applications, achieves its true potential as a versatile chiral synthon when converted to one of its simple analogs. Rudimentary manipulations of 1 allow rapid access to esters, amides, and various 0-protected derivatives. Each of these is widely used as a starting point in the tactical synthesis of medicinal agents, natural products, and agrochemicals as discussed in the remainder of this chapter. 

Four enantiopure hydroxyamidines were prepared from (5)-pyroglutamic acid by coupling of an (5)-malic acid derived A-allyliminium ion with p-naphthol, and from an (5)-serine-derived imide [80] (Figure 3.8). Unfortunately, their application to the catalytic Michael... 

Dividing both sides of the equation by d[B] gives the reverse of equation (1.3), defining the buffer capacity. Equations (1.2) and (1.3) have been defined for monoproteic acids, but are also applicable as an initial approximation to di-acids, such as tartaric and malic acids. 

In 1969, we [1, 2] succeeded in the industrial application of immobilized enzyme, l.e. immobilized amlnoacylase, for the continuous production of L-amino acids from acetyl-DL-amino acids. This is the first industrial application of immobilized enzymes in the world. Since then we [3, 4, 5, 6, T also carried out the Industrial applications of Immobilized microbial cells for the continuous productions of L-aspartic acid and L-malic acid using immobilized microbial cells with polyacrylamide gel. 

In succession to the L-aspartic acid production, in 1974 we succeeded in the third industrial application, i.e. the production of L-malic acid from fumarlc acid by immobilized microbial cells. L-Mallc acid is an essential compound in cellular metabolism, and is mainly used in pharmaceutical field. L-Malic acid can be produced by fermentative or enzymatic methods from fumarlc acid by the action of fumarase as follows. 

---