Phytic acid, hydrolysis

In the absence of mechanisms to accelerate phytic acid hydrolysis, the complexant will clearly persist in the environment for a long time. However, enzyme catalyzed phytate hydrolysis is known to be much faster than the thermal reaction (27). Thus biological activity may accelerate the hydrolysis reaction in soils. A recent report indicates that phytic acid is rapidly hydrolyzed by both aerobic and anaerobic microbiological processes in environmental samples (22). Complete phytate hydrolysis was observed in less than 40 days in anaerobic sediments, while half the available phosphate was released in 60 days under aerobic conditions (22). 

Miyamoto, S. K. Murota G. Kuwataz M. Imai A. Nagao J. Terao. Antioxidant activity of phytic acid hydrolysis products on iron ion-induced oxidative damage in biological system. ACS Symposium Series 2002, 807, 241—250. 

Antioxidant Activity of Phytic Acid Hydrolysis Products on Iron Ion-Induced Oxidative Damage in Biological System... 

Figure 3. Effect of phytic acid hydrolysis products on iron ion4nduced deoxyribose degradation.

Figure 5. Proposed pathway for phytic acid hydrolysis and its effect on iron ion induced oxidative damage of large intestinal mucosa.

Preparation by hydrolysis of phytin isolated from maize steep water [Ca- and Mg-salts of phytic acid (inositol hexa(dihydrogen phosphate))] with diluted sulfuric acid or with water under pressure. 

Protein-rich rape seed residues from biodiesel production plants are rich in phenolic compounds, glucocinolates and phytic acid. Phenolic compounds and phytic acid could be used as potent antioxidants in cosmetic and pharmaceutical formulations (Shamsuddin, 1995 Amarowicz and Shahidi, 1994 Wanasundara et al., 1996 Oatway et al., 2001). Derivatives from glucosinolate hydrolysis, including isothiocyanates, thiocyanates and nitriles, could be used as anticarcinogenic agents, biopesticides and flavour compounds (Halkier and Gershenzon, 2006). 

Phosphate is better used when supplied by food than when supplied by phosphate salts, such as potassium phosphate. The food phosphate occurs largely as phosphate esters and, with gradual hydrolysis, enters the body relatively slowly and is used efficiently in the metabolic processes. Phosphate supplied as inorganic phosphate is rapidly absorbed, with a tendency to be excreted in the urine rather than to be used by tissues (Schuette and Linkswilcr, 1962). The phosphate in bran occurs largely in the form of phytic acid (inositol hexaphosphate). The phosphate groups of fhis compound may be only partially hydrolyzed in the gut- Phytic acid tends to be excreted via the fecal route as a complex with iron or calcium. 

Phytate Hydrolysis Kinetics. An approximately 0.1 M solution of phytic acid was adjusted to the desired pH (measured at room temperature), sealed in a glass ampoule... 

Table II. Hydrolysis of phytic acid at elevated temperatures.

Phytic acid will form pyrophosphate complexes (10.36c). Phosphates of myo-inositol containing less than 6 ester OP(0)(OH)2 gronps have been obtained from plants and detected in soils. Mixtures of these lower phosphates are known to be produced by enzyme-catalysed hydrolysis of phytic add, and inositol monophosphate is a degradation product from phosphatidyl inositol (Chapter 11.3). Some varieties have been laboratory synthesised [50-52]. 

Phytic acid, myo-inositol hexakis (dIhydrogen phosphate), as-l,2,3,S-tnns-4,6-cyclohexanehexol-hexaphosphate a major phosphate storage compound in plants, which is especially abundant in oil seeds, legumes and cereal grains. It is the hexaphosphate of A/yo-inositol (see), in which each OH-group of myoinositol is esterified with phosphoric acid. Calcium and magnesium salts of P.a. are known as phytin. The commercial preparation of myo-inositol involves extraction of P. a. from com (maize) steep liquor, hydrolysis of the P.a. to myo-inositol and inorganic phosphate, and crystallization of the myo-inositol from water. 

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