Inositol Penta Research Articles

Utilization of Phytic Acid by Cooperative Interaction in Rhizosphere

Utilization of Phytic Acid by Cooperative Interaction in Rhizosphere

Effects of three conventional cooking methods on vitamin C, tannin, myo-inositol phosphates contents in selected Thai vegetables

Vegetables commonly consumed in Thailand were analyzed for their vitamin C, tannin and total phytate (inositol penta- (IP5) and hexasphosphate (IP6)) contents. Three conventional household cooking methods, namely blanching, boiling and stir-frying, were used to evaluate the effects of cooking. IP5 and IP6 content were determined using ion-pair reverse-phase chromatography. Vitamin C and tannin content were analyzed spectrophotometrically. Vitamin C content for raw and cooked vegetables ranged from 0.5–83.6 to 0.2–70.8 mg/100 g, respectively. Stir-fried pagwanpa ( Melientha suavis Pierre.), pagwanban ( Sauropus andogynus (L) Merr.) and cowslip creeper flower ( Telosma minor Craib) were excellent sources of vitamin C (64.4–70.8 mg/100 g). High tannin content was found in lead tree (“Yod-kratin”, Acacia farnesiana Willd.; 1353 and 679 mg/100 g tannic acid equivalent for raw and blanched sample, respectively), while neem tree ( Azdirachta indica A. Juss) contained high phytate (52 and 38 mg/100 g for raw and blanched sample, respectively). Blanching, stir-frying and boiling caused a decrease in the total vitamin C, with losses from 14% to 95%, the greatest loss being found in boiled bitter cucumber ( Monordica charantia Linn.) (95%), whereas retention of total phytate and tannin was around 58–79% for phytate and 44–93% for tannin. Although conventional boiling method was an effective method to reduce tannin and phytate content in vegetables, it also reduced the content of vitamin C.

Influence of phosphorus level and soaking of food on phosphorus availability and performance in growing-finishing pigs

AbstrctThe effects of 1-h soaking of a pig diet based on wheat and barley with low (4·1 g P per kg) and high (6·8 g P per kg) total phosphorus (P) content on total tract apparent digestibility and performance in growing-finishing pigs were studied in a balance and a performance trial respectively. Phosphorus bound to inositol penta- and hexaphosphate (IP5-IP6) was reduced by proportionately 0·1 in the soaked food. Soaking numerically increased the apparent digestibility of P. The digestibility of P did not differ between the dry high P and the soaked low P. Excretion of P in urine was correlated (R2= 0·84) with the intake of digestible P. The average daily weight gain, final body weight and carcass weight were lower (P< 0·001), and the energy conversion ratio was higher (P< 0·001) in the dry low P treatment than in the other treatments. Pigs on the low P diets had lower levels of inorganic P in serum (P< 0·01) and slightly higher serum Ca values (P< 0·05) and there were no effects of soaking. The density of femur was lower (P< 0·01) in both the low P treatments than in the high P treatments, and soaking of the low P diet improved (P< 0·01) femur density. In conclusion, a 1-h soaking of pig food in water appears to be sufficient to improve P availability and growth performance.

Use of soaking to enhance the bioavailability of iron and zinc from rice‐based complementary foods used in the Philippines

AbstractComplementary foods used in the Philippines are predominantly rice‐based, although enrichment with mung beans and sesame seeds is recommended despite their high content of phytic acid, a potent inhibitor of iron and zinc absorption. We have investigated the effect of soaking on the inositol penta‐ (IP5) and hexaphosphate (IP6) (analysed by HPLC), zinc, iron and calcium (via AAS) content of rice‐based complementary foods with and without the addition of mung beans and sesame seeds. Soaking rice flour for 1, 6 and 12 h at 30 °C reduced the content of IP5 + IP6 by 60, 65 and 98% respectively, with only slight changes in zinc, iron and calcium. Levels of IP5 + IP6 were reduced by 10 and 47% by soaking mung bean flour, but not whole beans, for 1 and 6 h respectively. In conclusion, soaking can be used to reduce the IP5 and IP6 content of complementary foods based on mung bean flour and/or rice flour and thus enhance the bioavailability of iron and zinc.© 2002 Society of Chemical Industry

Inositol phosphates influence iron uptake in Caco-2 cells.

Phytate, inositol hexaphosphate (InsP(6)), may be hydrolyzed to inositol phosphates with lower degree of phosphorylation, i.e., inositol penta- to monophosphates (InsP(5)-InsP(1)), during food processing. Each of these lower inositol phosphates exists in different isomeric forms. The objective of this study was to determine if different isomers of InsP(3)-InsP(5) (Ins(1,2,4)P(3), Ins(1,2,3)P(3), Ins(1,2,6)P(3), Ins(1,3,4)P(3), Ins(1,2,3,4)P(4), Ins(1,2,5,6)P(4), Ins(1,2,4,5,6)P(5), and Ins(1,3,4,5,6)P(5)) and InsP(6) affect the uptake of iron. We studied the iron absorption in vitro using the human intestinal epithelial cell line, Caco-2. Addition of a 2-fold molar excess of InsP(6) or InsP(5) in proportion to Fe (1 h incubation at 37 degrees C) reduced iron uptake by 46-52% (p < 0.001). Neither InsP(4) isomers nor InsP(3) isomers affected iron uptake significantly at 1 h incubation with a molar InsP:Fe level of 2:1. Iron uptake was shown to not be a function of the isomeric form of inositol phosphates. The inositol phosphate isomers did not seem likely to interact with each other through iron to form more stable iron complexes. At a molar InsP:Fe level of 20:1 an inhibitory effect of InsP(4) was found, while InsP(3) did not affect the iron absorption even at a 20-fold molar excess.

Phytate hydrolysis in pigs fed a barley-rapeseed meal diet treated with Aspergillus niger phytase or steeped with whey

The degradation of phytate (myo-inositol hexaphosphate) in a barley-rapeseed meal (80:20) diet due to supplemented Aspergillus niger phytase and steeping (soaking at 40 °C for 3 h with feed to water ratio 1 kg:1 L) with whey was studied in eight growing pigs (initial weight 27.8 kg). Phytate and its hydrolysis products (inositol penta-, tetra- and triphosphates, abbreviated IP5, IP4 and IP3) in diets and feces were determined using ion-pair high-performance liquid chromatography (HPLC). Different isomeric forms of inositol tetra- and pentaphosphates were studied utilizing high-performance ion chromatography (HPIC). Supplementing the diet with microbial phytase resulted in a 47% reduction in the amount of fecal phytate. Whey steeping of the diet reduced fecal phytate by 35%. Further reduction of the amount of fecal phytate (64%) was demonstrated in pigs fed the diet both steeped with whey and supplemented with microbial phytase, compared with pigs fed the untreated diet. Identification of IP4 and IP5 isomers in fecal samples showed which kind of phytase enzyme was active during phytate hydrolysis in the digestive tract. From these data, it was concluded that pigs fed the basal or whey steeped diet, without supplemented microbial phytase, had higher relative fecal amounts of DL-Ins(1,2,3,4,5)P5, compared with pigs fed the microbial phytase supplemented diets. Adding microbial phytase to the diet increased the relative amount of DL-Ins(1,2,4,5,6)P5 in feces. With whey steeping of the diet, the relative amount of DL-Ins(1,2,3,4)P4 isomer in feces was increased and the relative amount of DL-Ins(1,2,5,6)P4 isomer was decreased. Key words: Inositol phosphates, steeping, Aspergillus niger phytase, pig

Comparison between steeping and pelleting a mixed diet at different calcium levels on phytate degradation in pigs

The degradation of phytate (inositol hexaphosphate) in the stomach, small intestine and colon was studied in 36 female pigs. A comparison was made between steeped (9 h, room temperature, feed:water 1:2.5) and pelleted diets with or without calcium carbonate supplementation (12.5 g kg−1). The diet was composed of barley, rapeseed cake and peas in the proportion 70:15:15. Dietary and intestinal content of phytate and its hydrolysis products (inositol penta-, tetra- and triphosphates) were determined using HPLC ion-pair chromatography. Steeping the feed for 9 h at room temperature reduced the phytate content by 45% and increased the amount of free phosphorus threefold. Pelleting the diet reduced phytate content by 7%. Supplementation with Ca decreased dietary phytate reduction. Steeping of the diet reduced ileal phytate content by 40% compared with pelleting. Apparent phosphorus absorption from ileal digesta was 10% lower when pigs were fed the pelleted diet, as compared to the steeped diet. Calcium carbonate supplementation impared inositol hexaphosphate degradation in the colon of pigs, but did not affect phytate degradation in the stomach and small intestine. Calcium carbonate supplementation, moreover, depressed apparent P uptake in the stomach/small intestinal region, as well as in the total gastrointestinal tract, for all feed treatments. Key words: Phytate degradation, inositol phosphates, steeping, pelleting, calcium, pigs

Inositol Phosphate Content of Some Cereal-Based Foods

An HPLC method was used to quantify contents of inositol hexa-, penta-, tetra-, and triphosphate in various bread, breakfast cereal, pasta, and rye flour samples collected froom Finnish commercial mills and retail outlets. The highest contents in breakfast cereals (phytic acid over 10 μmol/g dry wt) were found in whole-meal porrige flakes, followed by müselies. Inositol hexa-, penta-, tetra-, and triphosphate levels in rice crispies and corn flakes were consistently low. Inositol hexaphosphate contents in pastas were about 5 μmol/g dry wt. The phytic acid contents in rye flours and whole-meal porrige flakes were on the same level and rye flours had only very low contents of inositol penta- and traces of inositol tetra- and triphosphates. The highest total inositol hexa-, penta-, tetra-, and triphosphate contents in breads were found in crispbreads, breads containing wheat and oat, and Finnish sourdough rye bread. Breads made predominantly of wheat had lower contents. Most of the inositol hexaphosphate in the various sourdough breads studied (rye breads, buckwheat, some domestic crispbreads, and a wheat and potato bread) had hydrolyzed, since the content of inositol hexaphosphate was low compared to that of inositol penta-, tetra-, and triphosphates. The average Finnish per capita intake of phytic acids from cereal products is roughly 370 mg/day. Dietary fiber is mainly supplied by cereal products, rye bread being the single most important source therein. Thus these foods were also assumed to be the most important sources of phytic acid. However, the share of rye bread (Finnish sourdough dark rye bread) is not a significant source of phytic acid. Cereal products, and rye bread in particular, are very important sources of inositol hexa-, penta, tetra-, and triphosphates.

Inhibition of porcine brain inositol 1,3,4-trisphosphate kinase by inositol polyphosphates, other polyol phosphates, polyanions and polycations

We have partially purified an enzyme activity that phosphorylates inositol 1,3,4-trisphosphate from porcine brain, rat liver and bovine testis by FPLC chromatography on Q-Sepharose anion-exchange resin and Heparin-agarose. The products of this reaction were inositol 1,3,4,6-tetrakisphosphate and inositol 1,3,4,5-tetrakisphosphate. The same enzyme appears to be responsible for both 6-kinase and 5-kinase activities against inositol 1,3,4-trisphosphate (the 6-kinase: 5-kinase activity ratio is approximately 4 to 1), has a pH optimum of ∼ 6.8 and requires Mg 2+ for activity. The K m values of the enzyme for inositol 1,3,4-trisphosphate and ATP were ∼ 0.5 μM and ∼ 100 μM, respectively. Inositol 3,4,5,6-tetrakisphosphate, inositol 1,3,4,6-tetrakisphosphate and inositol 1,3,4,5-tetrakisphosphate are all competitive inhibitors with K i values of 0.4 μM, 3 μM and 5 μM, respectively, well within their likely intracellular concentration ranges: they inhibited 6-kinase and 5-kinase activities equally. 2,3-Bisphosphoglycerate and spermine were also competitive inhibitors, with K i values of 0.8 mM and 12 mM, respectively. Dextran sulphate was a non-competitive inhibitor with a K i of ∼ 15 μM, and poly- l-lysine (IC 50 ∼ 200 μM), polyvinylsulphate (IC 50 ∼ 250 μM) and heparin (IC 50 ∼ 2 mg/ml) also inhibited. Inhibition by these compounds suggests that inositol 3,4,5,6-tetrakisphosphate (and to a lesser extent inositol 1,3,4,5-tetrakisphosphate and other naturally occurring intracellular ions) may restrict the synthesis of inositol 1,3,4,6-tetrakisphosphate and hence regulate the rate of inositol penta- and hexakisphosphate synthesis from receptorgenerated inositol phosphates.

Overestimation of phytic acid in foods by the AOAC anion-exchange method

The currently used AOAC method may overestimate the phytic acid (inositol hexaphosphate) content of processed foods. These foods generally contain the lower phosphates (inositol penta-, tetra-, and triphosphate) in addition to phytic acid. These lower phosphates are included in the calculation of phytic acid determined by the AOAC anion-exchange method. The HPLC method quantitates phytic acid and the other inositol phosphates as separate entities. Research has indicated that phytic acid, and to a lesser degree other inositol phosphates, may reduce mineral bioavailability of foods

Macromolecule‐P associations and inositol phosphates in some chilean volcanic soils of temperate regions

Abstract Total organic P, humic and fulvic acid‐P associations and inositol phosphates in nine volcanic soils of southern Chile were determined. The concentration of organic P (Po) ranged from 654 to 1942 ppm accounting for 49% to 64% of total soil P. Phosphorus associated to humic (HA‐P) and fulvic acids (FA‐P) accounted for 51–68% and 32–49% of Po, respectively. Inositol penta‐ and hexaphosphates represented 42% to 67% of Po suggesting that significant amounts are associated with both humic and fulvic acids. Po content was significantly correlated to organic C, total soil P and HA‐P. HA‐P and FA‐P fractions obtained from the most representative soil were examined by dyalisis and gel filtration. While approximately 96% of HA‐P presented a molecular weight higher than 100,000 daltons, 53% of FA‐P had a molecular weight under 12,000 daltons. It is suggested that these more labile organic P forms would be more easily mineralized, thus increasing the available P pool.

Degradation Products of Bran Phytate Formed during Digestion in the Human Small Intestine: Effect of Extrusion Cooking on Digestibility

To investigate the digestion of phytate in the stomach and small intestine in humans, studies were performed in subjects with established ileostomy. A recently developed high performance liquid chromatography method made it possible to analyze phytate and its degradation products in food and digesta. The digestibility of phytate in raw bran and extruded bran was investigated in seven ileostomy patients. Each subject was studied for two 4-d periods while consuming a constant low fiber diet with the addition of either 54 g/d of a bran-gluten-starch mixture or the corresponding extruded product. During passage through the subject’s stomach and small intestine 58%, on average, of the phytate in unprocessed bran was hydrolyzed to inositol penta-, tetra- and triphosphates. When bran was subjected to extrusion cooking, 25% of the inositol hexaphosphate was hydrolyzed to penta- and tetra-phosphate and the phytase activity ceased. Essentially no phytate digestion occurred when the ileostomy subjects consumed the extruded product. The reduced digestibility might be due to the lost phytase activity or to formation of indigestible phytate complexes during extrusion cooking.

Inhibitory effect of inositol phosphates on parathyroid hormone-induced bone resorption in organ cultures.

This study investigates the ability of phytic acid, its inositol phosphate derivatives (inositol penta-, tetra-, tri-, di-, and monophosphate), and inorganic phosphate to inhibit parathyroid hormone (PTH)-induced resorption of fetal rat long bones in organ culture. Pregnant rats injected with 45Ca on the 18th day of gestation were killed the next day and their fetuses removed. Half of each pair of dissected long bones was incubated in a chemically defined control medium, while the contralateral half was incubated in medium containing PTH or PTH plus the phosphate compound to be tested. 45Ca released into the medium was indicative of the amount of bone resorption. All phosphate compounds tested inhibited resorption. The inositol phosphates should be studied further to assess their suitability as therapeutic agents for treatment of metabolic bone diseases involving increased turnover.

Inositol penta‐ and hexaphosphate content of some cocoa soils in Ghana

AbstractThe inositol penta‐ and hexaphosphate content of some typical cocoa soils in Ghana was measured by anion exchange chromatography with HCOONH4 as eluant. The values which ranged from 6 to 35 ppm P (average 18 ± 8 ppm P) and accounted for 6% to 40% (average 14%) of the organic phosphorus are within those ranges reported for Canadian, Nigerian, but much lower than those for Scottish soils.The penta‐ and hexaphosphate content of the soil significantly correlated with total P, organic P, organic C, total N, Fe and P retention capacity.Incubation of soil for 11 weeks did not alter the inositol penta‐ and hexaphosphate content of the soil. Inorganic P adsorption could be decreased by adding inositol hexaphosphate. These data support the suggestion that a role of the esters in nutrition of crops is probably through the indirect effect of blocking of retention sites and agents which would otherwise be free to bind inorganic phosphorus.

Amounts and mineralization of organic phosphorus compounds and derivatives in some surface soils of bangladesh

Concentrations of a few organic phosphorus compounds and their hydrolysis products have been determined in a number of Bangladesh soils. The amounts of DNA and its derivatives, inositol penta- and hexaphosphates, ranged from 0.16 to 1.30, and 18.5 to 130.0 ppm, respectively. The hydrolysis products of phospholipids such as choline, ethanolamine and glycerophosphate ranged from 0.36 to 3.29, 0.28 to 2.52 and 0.20 to 1.05 ppm, respectively. Multiple correlation suggested that pH, organic matter, organic phosphorus and total phosphorus were collectively related to the amounts of different organic phosphorus fractions in soil samples. Individually, DNA and its derivatives were found to be significantly related to total phosphorus and inositol penta- and hexaphosphates to organic phosphorus. Choline was significantly related to organic matter, organic phosphorus and total phosphorus; ethanolamine to organic matter and total phosphorus; and glycerophosphate to organic phosphorus. Moisture and lime promoted progressive mineralization of organic phosphorus with time. Potassium dihydrogen phosphate, glucose and ammonium sulphate showed rapid initial and final mineralization. In contrast, the application of compost caused an initial luxury immobilization followed by a marked increase in mineralization with time. Maximum mineralization was observed when ammonium sulphate was added to samples in submerged conditions. The least mineralization occurred when lime was added to samples at 50% of field moisture capacity.

Inositol hexaphosphate guanosine diphosphate phosphotransferase from Phaseolus aureus

Inositol hexaphosphate guanosine diphosphate phosphotransferase which transfers phosphate from inositol hexaphosphate to guanosine diphosphate, synthesizing guanosine triphosphate, has been isolated from germinating mung bean. A purification of 86-fold with 33% recovery has been obtained and the protein was made homogeneous after polyacrylamide gel electrophoresis. The MW of this enzyme was ca 92000. The optimal pH was 7·0 and Mn 2+ was stimulatory. Inositol hexaphosphate was the most active donor of the phosphoryl group (P) to GDP. Inositol penta- or tetra-phosphate (mixed) was partially active, but inositol pentaphosphate produced in this reaction did not act further as phosphate donor. The transfer of P from inositol hexaphosphate was mediated through a phosphoprotein. Polyphosphate (poly Pi), pyrophosphate (PPi) and orthophosphate (Pi) were inactive in this reaction. ADP, CDP and UDP could not substitute for GDP, neither could dGDP nor GMP accept P from inositolphosphate. GTP inhibited the reaction, but ATP did not interfere with the reaction. The products have been shown to be [GMP- 32P] and inositol pentaphosphate by several criteria. The reaction is practically irreversible. K m values for GDP and inositol hexaphosphate were 1·1 × 10 −4 M and 1·6 × 10 −6 M respectively.

SOME EFFECTS OF FERTILIZERS AND FARMYARD MANURE ON THE ORGANIC PHOSPHORUS IN SOILS

SummaryThe amounts of P applied cumulatively to a neutral arable soil (pH 7.1–7. in 0.01M CaCl2) at Rothamsted, as farmyard manure, alone or with superphosphate, which were converted to organic P in 100 years ranged from 18 to 44 μg P/g of soil (0–23 cm). Superphosphate alone (3300 kg P/ha) slightly lessened the total organic P in the soil. Neither farmyard manure nor super‐phosphate significantly changed the amounts (38 to 42 μg P/g) of inositol penta‐ and hexaphosphate in these soils. In the surface layers (0–7.5 cm) of soils from permanent grassland at Rothamsted, superphosphate (3370kg P/ha) increased organic P by 134 μg P/g at pH 4.5 and 19 μg P/g at pH 6.5, about 6 and 1 per cent respectively of the P remaining from superphosphate applied cumulatively since 1858. In the sub‐surface layers (7.5–23 cm) superphosphate increased organic P by 93 μg P/g at pH 4.5 and 62 μg P/g at pH 6.2, about 18 and 10 per cent respectively of the P remaining from superphosphate. The sum of inositol penta‐ and hexaphosphates accounted for 32 per cent at pH 4.5 and 21 per cent at pH 6.5 of the increases in organic P in the surface layers and 45 per cent and 26 per cent in the sub‐surface layers at pH 4.5 and 6.5 respectively.Superphosphate (1260–2100 kg P/ha) applied intermittently or cumulatively increased total organic P by 19 to 52 μg P/g and inositol penta‐ and hexaphosphates by 13 to 17 μg P/g in acid tea soils (pH 3.2–3.4) from Georgia, U.S.S.R. Rock phosphate (510–1020kg P/ha) applied cumulatively had no effect on either the total organic P or the inositol P in acid tea soils (PH 3.6–3.7) from Ceylon.

Fractionation of Organic Phosphorus in Lake Sediments

AbstractThe organic phosphorus of 10 Wisconsin lake sediments of diverse properties was fractionated on the basis of extractability and anion exchange properties. The fractionation procedure involved sequential extraction of the sediments with 1N HCl for 1 hour (HCl‐Po), cold 0.3N NaOH for 16 hours (Cold NaOH‐Po), and hot 0.3N NaOH for 8 hours (hot NaOH‐Po) followed by anion exchange chromatography of the NaOH extracts into three fractions: fraction I, the 0.3N NaOH eluate, contained organic P that was not retained by the resin; fraction II, the 0.5M LiCl eluate, contained organic P with exchange properties similar to inorganic orthophosphate and monophosphate esters; fraction III, the 1M LiCl + 0.2N HCl eluate, contained organic P comparable to polyphosphate esters in exchange properties.Total organic P extracted by the fractionation method was comparable to that removed by the standard Mehta et al. extractants indicating that the fractionation method provided valid total organic P data as well as information on the forms of organic P present in sediments.HCl‐Po constituted 6 to 17%, cold NaOH‐Po 60 to 80%, and hot NaOH‐Po 10 to 30% of the total organic P of the sediments. Anion exchange chromatography of the NaOH extracts showed that most of the organic P (48 to 80%) was present in fraction I, the fraction likely composed of high molecular weight humic‐fulvic complexes. Fraction II contained 14 to 36% and fraction III less than 10% of the organic P in the NaOH extracts. Total inositol penta‐ and hexa‐phosphates comprised less than 10% of the total organic P of the sediments. The total and major fractions of sediment organic P were related to organic C, total N and oxalate‐extractable Al, but were not related consistently to any other sediment property or to the trophic level of the lake.

CONTENT OF INOSITOL PENTA‐ AND HEXAPHOSPHATES IN SOME CANADIAN SOILS

SummaryThe combined amounts of inositol penta‐ and hexaphosphates in a number of Canadian soils of differing origin have been measured. The esters were precipitated as barium salts from alkali extracts and purified by anion‐exchange chromatography; their identity was confirmed by paper‐partition chromatography. An alternative method involving precipitation of the esters as ferric salts in acid medium was found to give much lower values, probably because of incomplete precipitation.Values for eighteen surface soils ranged from 20 to 71 and for twelve subsoils from 18 to 43 ppm P. The amounts found were related to the contents of both total phosphate and total organic phosphate, and accounted, on average, for 6 per cent of the former and 17 per cent of the latter. A correlation of +0.67 (P &lt; 0.01) was found with orthophosphate retention capacity but correlations with soil N and C contents were poor. Amounts of the esters were higher in forest soils than in grassland soils.

Inositol phosphates in some Australian soils

A study was made of the total amount of inositol penta- plus hexaphosphate in a range of Australian soils. The amounts varied widely, ranging from 1.0 to 356 p.p.m. P, and accounted for 0.4-38% of the total organic phosphorus, with an average value of 16%. Neither the absolute content of inositol phosphate nor its proportion to the total organic phosphorus could be closely associated with any particular soil property. In undisturbed soil profiles the inositol phosphates tended to be concentrated near the soil surface. Inositol phosphates were shown to accumulate in soils when organic matter accumulated under leguminous pasture and to decrease when organic matter was lost from soils as a result of cultivation. The relative decrease of inositol phosphates in the cultivated soils was much smaller than that of the organic phosphorus as a whole.