Analysis malic acid

Ergonovine (100, R = NHCH(CH3)CH2 0H) was found to yield lysergic acid (100, R = OH) and (+)-2-aminopropanol on alkaline hydrolysis during the early analysis of its stmcture (66) and these two components can be recombined to regenerate the alkaloid. Salts of ergonovine with, for example, malic acid are apparently the dmgs of choice in the control and treatment of postpartum hemorrhage. 

Year and month of analysis Sugar (Brix) % bio vs. IP Malic acid (g/1) bio vs. IP Fruit flesh firmness bio vs. IP Quality index ) bio vs. IP Other parameters bio vs. IP... 

Some further peculiar observations have been made regarding optically active malic acid. Since at that time, 1896 X-ray analysis was not available, Walden suggested the change to be taking place through the following cycle, based on the sign of rotation. 

The absolute configuration of the major isomers of spirolactone 102 and amide 103 was ISySRyl R, based on the known configuration of malic acid and determination of the relative configuration by an X-ray structure analysis of amide 103 [62]. 

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... 

D KIE of 6.35 has been observed in the oxidation of a-deuteriomandelic acid by pyri-dinium bromochromate to the corresponding oxo acid. The analysis of the D KIE indicated that the reaction involves a symmetric transition state443. The oxidations of phosphinic and phosphorous acids by pyridinium bromochromate exhibits a substantial primary deuterium KIE444. The hydroxyacids, glycolic, lactic, mandelic and malic acids are oxidized by pyridinium hydrobromide perbromide in acetic acid-water mixtures to oxo acids445. The primary KIE in the oxidation of a-deuteriomandelic acid is kn/kn = 5.07, and it does not exhibit a solvent isotope effect. A mechanism involving hydride ion transfer to the oxidant has been proposed445. 

Examples of the use of immobilized enzymes in food processing and analysis have been listed by Olson and Richardson (1974) and Hultin (1983). L-aspartic acid and L-malic acid are produced by using enzymes contained in whole microorganisms that are immobilized in a polyacrylamide gel. The enzyme aspartase from Escherichia coli is used for the production of aspartic acid. Fumarase from Brevibacterium ammoni-agenes is used for L-malic acid production. 

The precipitation of aluminium hydroxide by solutions of sodium hydroxide and ammonia does not take place in the presence of tartaric acid, citric acid, sulphosalicylic acid, malic acid, sugars, and other organic hydroxy compounds, because of the formation of soluble complex salts. These organic substances must therefore be decomposed by gentle ignition or by evaporating with concentrated sulphuric or nitric acid before aluminium can be precipitated in the ordinary course of qualitative analysis. 

This involves the Rebelein method. A sample of dialysed wine is reacted with metavanadate to produce a red colour at 37°C in acid medium. The absorbance is measured at 520 nm. High concentrations of malic acid and sugars can interfere with the analysis. 

Hydroxycarboxylic acids, which include citric acid, malic acid, lactic acid, etc., are benign to the environment and very convenient for the solution processing. Moreover, since these reagents can form stable complexes with other cations, they rarely yield a precipitate. For several complexes single crystals of well-defined composition suitable for the X-ray structural analysis were isolated. Thus, these water-soluble titanium complexes of hydroxycarboxylic acids are promising precursors for the synthesis of ceramics from an aqueous solution and their industrial utilization is expected in the future. In this chapter we decribe the method of synthesis, structural analysis, and stability of these complexes. The examples of multicomponent oxide materials preparation using these compounds are presented. 

Figure 1.7 HPLC chromatogram of organic acids analysis of Prosecco grape must sample. 1. tartaric acid, 2. malic acid, 3. citric acid, 4. shikimic acid. Analytical conditions Lichrospher 100 RP-18 (250 x4mm, 5p,m) column (Merck, Darmstadt, Germany) at room temperature, detection at wavelength 210 nm, sample volume injected 20/xL solvent H3P04 5 x 10 3 M with isocratic elution at flow rate 0.6 mL/min...

Figure 1.11 Analysis of an organic acids standard solution. 1. citric acid, 2. tartaric acid, 3. malic acid, 4. succinic acid, 5. lactic acid, 6. acetic acid. Analytical conditions column Aminex HPX-87H (300 x 7.8mm, 9(jim) at 65 °C (Bio-Rad Laboratories, Richmond, CA) detection at wavelength 210 nm sample volume injected 10p,L solvent H2S04 0.026 N with isocratic elution at flow rate 0.8mL/min...

Another recent example is the identification of (S)-malic acid 1-0-D-glucopyrano-side, also referred to as Morelid, by the TDA approach [21 ]. It has been isolated from morel mushrooms and identified as a new umami-like tasting compound with a taste threshold of 6 mol/L. A comparative taste profile analysis of a 20 mM aqueous solution of Morelid and a 4 mM aqueous solution of MSG showed similar intensities for the umami-like taste [21], However, the oral evaluation of the glycoside did not show any salty note as compared to MSG. 

Fumaric acid is another organic acid produced by Rhizopus, in particular Rhizopus stolonifer. The presence of fumaric acid has also been found to arise from the addition of synthetic malic acid and is sometimes considered as an index of adulteration when confirmed by analysis of D-malic acid (not present in malic acid from natural sources) (Trifiro et al., 1997). 

Figwe 8.9. Wine analysis by high re.solution ion exclusion. Analysis Conditions Column Transgenomic ION-300 Eluent 0.005 N H2SO4 Flow rate 0.3 mL/min Temperature 60 °C Detection DrI Sample 1. citric acid. 2. tartaric acid, 3. glucose. 4. malic acid, 5. fructo.se.6. acetic acid. 7. glycerol, 8. methanol. 9. ethanol. 

We carried out another synthesis of (2R,6S,8R)-8Sr, as shown in Figure 4.37, by employing (.S )-malic acid as the starting material.67 In this synthesis, the enantiomeric purity of the intermediate C was rigorously proved to be 100% ee as checked by the H-NMR analysis of its a-methoxy-a-trifluoromethylphenylacetate (MTPA ester). Subsequently, C was converted to (2R,6.S ,8R)-88, whose rotation value was [a]o23 +60.1 (pentane). As a byproduct of this synthetic study, (2R,6R,8.S )-2,8-dimclhyl-l,7-dioxaspiro[5.5]undecane (F ) was synthesized from D, which was obtained by isomerization of E. This isomerization was made possible by the fact that the crystalline 3,5-dinitrobenzoate of D precipitated, while that of E remained oily. 

The technical feasibility of an immobilized cell system was demonstrated on a laboratory scale for use in reducing limonoid bitterness of citrus juices. The treatment caused no significant adverse effect on the other juice constituents as judged by analysis of ascorbic acid, citric acid, malic acid, sucrose, glucose and fructone. 

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