Myo-inositol hexaphosphate

G. R. Findenegg and J. A. Nelenians, The effect of phytase on the availability of P from myo-inositol hexaphosphate (phytate) for maize root. Plant Soil 754 189 (1993). 

Phytate (myo-inositol hexaphosphate Fig. 15.3, structure 33) is found in many food species and can be considered as a phytochemical. Its role in the plant is primarily as a phosphate store in seeds, but it is found in other tissues as well, for example, tubers (Harland et al., 2004). Phytate and its hydrolysis products are anti-nutrients that chelate metal ions and thus reduce their bioavailability (Persson et al., 1998 House, 1999). This is particularly a problem with cereal grains, but pre-processing can improve mineral absorption from these foods (Agte and Joshi, 1997). There is some concern that high phytate foods could also contain higher levels of toxic heavy metals caused by natural accumulation. Plants also contain phytate-degrading enzymes that can also influence metal ion bioavailability (Viveros et al., 2000). 

This enzyme [EC 3.1.3.26], also known as phytase, phy-tate 6-phosphatase, and myo-inositol-hexaphosphate 6-phosphohydrolase, catalyzes the hydrolysis of myoinositol hexakisphosphate to produce 1-myo-inositol... 

Hydrolysis of mt/o-inositol l(3),2-cyclic phosphate under acidic or alkaline conditions affords a mixture of myo-inositol l(3)-phosphate and myo-inositol 2-phosphate, with the former preponderating.275 As the cyclic phosphate may be prepared275 from the 2-phosphate, which is itself readily obtained from myo-inositol hexaphosphate by enzymic cleavage,268,276 and as the l(3)-phosphate may be isolated277 from the hydrolysis mixture, the reaction sequence provides a convenient way... 

Figure 5. Chair configuration of myo-inositol hexaphosphate, illustrating hydrogen bonding between phosphate groups 2 and 6. Hydrogen bonding between groups 3 and 5 is not shown for clarity.

Biswas, S., Maity, I.B., Chakrabarti, S., and Biswas, B.B., 1978b, Purification and characterization of myo-inositol hexaphosphate-adenosine diphosphate phosphotransferase from Phaseolus aureus. Arch. Biochem. Biophys. 185 557-566. 

Grases, E, Perello, J., Prieto, R.M., Simonet, B.M., and Torres, J.J., 2004, Dietary myo-inositol hexaphosphate prevents dystrophic calcifications in soft tissues A pilot study in Wistar rats. 

SYNS ALKOVERT FYTIC ACID HEXAKISpiHYDROGEN PHOSPHATE) MYOINOSITOL INOSITHEXAPHOSPHORSAEURE (GERMAN) INOSITOL HEXAPHOSPHATE MYO-INOSISTOL HEXAKISPHOSPHATE MYO-INOSITOL HEXAPHOSPHATE SAEURE DES PHYTINS (GERMAN)... 

Ognalaga, M., Frossard, E, and Thomas, E. (1994). Glucose-1-phosphate and myo-inositol hexaphosphate adsorption mechanism on geothite. Soil Sci. Soc. Am. /. 58, 332-337. 

Costello, A.J., Clonek, T. and Myers, T.C. (1975) P nuclear magnetic resonance-pH titrations of myo-inositol hexaphosphate. Carbohydrate Research 46, 1 59-1 71. 

Richardson, A.E., Hadobas, P.A., Hayes, J.E., O Hara, C.P. and Simpson, R.J. (2001) Utilization of phosphorus by pasture plants supplied with myo-inositol hexaphosphate is enhanced by the presence of soil micro-organisms. PlantandSoil 229, 47-55. 

Martin, J.K. and Cartwright, B. (1971) The comparative plant availability of P myo-inositol hexaphosphate and KHj PO added to soils. Communications in Soil Science and Plant Analysis2, 375-381. 

In animals, the myo-inositol is combined with phospholipids, while in plants it occurs mainly as salts of myo-inositol hexaphosphate, which is also known as phytic add (10.36a). 

Recently, the determination of phytic acid (myo-inositol hexaphosphate), which is believed to have an effect on the bioavailability of mineral substances, has become important. While phytic acid is not a food conshtuent in the United States, in other countries it is frequently added to foods as an anhoxidant [250,... 

Phytic acid (myo-inositol hexaphosphate) has been clearly established as a major phosphate reserve in many seeds, containing more than 50% of the total stored... 

Phosphates and phosphonates of biochemical interest and the forms adopted by ketose phosphates in aqueous solution have been discussed. The p a values of each of the six phosphoric monoester groups of wj o-inositol hexa-phosphate (phytic acid) have been determined by the use of P n.m.r. spectroscopy. The conformation adopted by myo-inositol hexaphosphate in basic and neutral solutions was also discussed. 

A study of the complexes formed between Na+ cations and some monosaccharides using 2 Na n.m.r. measurements is noted in Chapter 18. Studies on myo-inositol hexaphosphate using n.m.r. spectroscopy and of the com-plexation of borax with D-glucose and D-glucobioses are referred to in Chapter 6. 

Synenyms Hexakis (dihydrogen phosphate) myo-inositol Inositol hexaphosphate myo-lnositol, hexakis (dihydrogen phosphate) myo-inositol hexakisphosphate myo-inositol hexaphosphate Phytic acid (INCI)... 

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