Changes in Inositol Phosphates in Low Phytic Acid Field Pea (<i>Pisum sativum</i>L.) Lines during Germination and in Response to Fertilization

Inositol phosphates are the main form of phosphorous (P) storage in legume seeds. Mutants low in inositol hexaphosphate (IP6), also known as phytic acid (PA), have been developed to increase iron (Fe) bioavailability and reduce P waste to the environment. The objectives of this study were to determine 1) inositol-P form changes during germination, and 2) the effect of P fertilizer application on seed PA, total P, and Fe concentration of three field pea (Pisum sativum L.) cultivars and two low-PA lines grown under greenhouse conditions. Low-PA field pea lines clearly had lower PA (1.3 - 1.4 mg·g-1) than cultivars (3.1 - 3.7 mg·g-1). Phytic acid concentration in both cultivars and low-PA lines decreased during germination, but tended to increase seven days after germination. Levels of inositol-3-phosphate-phosphate (IP3-P;0.6 mg·g-1) and inorganic P (1.8 - 2.0 mg·g-1) were higher in low-PA lines than in the field pea cultivars. Reduction of PA in low-PA line seeds may reduce seed Fe and total P concentrations, as levels in the low-PA lines (37 - 42 mg·kg-1 Fe;4003 - 4473 mg·kg-1 total P) were typically less than in field pea cultivars (37 - 55 mg·kg-1 Fe;3208 - 4985 mg·kg-1 total P) at different P fertilizer rates. Overall, IP3 is the major form of P present in low-PA field pea lines during germination;however IP6 is the major form of P present in field pea cultivars. Therefore, low-PA field pea lines could be a potential solution to increase Fe bioavailability, feed P utilization, and reduce P waste to the environment.

Inositol hexaphosphate-induced enhancement of natural killer cell activity correlates with suppression of colon carcinogenesis in rats

AIM： To investigate the anti-neoplastic effect of inositol hexaphosphate （InsP6 or phytic acid） on dimethylhydrazine （DMH）-induced colon tumor in rats and its effect on blood natural killer （NK） cell activity. METHODS： Healthy Wistar rats, 4 wk old, were divided into control group （fed with common food） and InsP6 group （fed with common food＋2% sodium inositol hexaphosphate in the drinking water）, 15 rats in each group. Both groups were injected with 1,2-dimethylhydrazine subcutaneously （20 mg/kg body weight） once a week for 20 wk. Rats were killed after 21 wk. The whole large intestine was isolated to determine the general condition of tumors and to test blood NK cell activity by lactate-dehydrogenase-release assay. RESULTS： Administration of InsP6 significantly increased blood NK cell activity in DMH-induced colorectal tumor in rats. InsP6 group had a smaller tumor size on average and a smaller number of tumors than the control group. Its mortality was also higher than that in control. However, the variables of body weight and tumor incidence were not significantly different between the two groups. CONCLUSION： InsP6 can increase blood NK cell activity in DMH-induced colon tumor in rats and inhibit tumor growth and metastasis in rats.

RNAi-Mediated Silencing of ITPK Gene Reduces Phytic Acid Content,Alters Transcripts of Phytic Acid Biosynthetic Genes,and Modulates Mineral Distribution in Rice Seeds

Phytic acid is the principal storage form of phosphorus in plant seeds and an essential signalling molecule in several regulatory processes of plant development.However,it is known as an anti-nutrient compound owing to its potent chelating property.Thus,reducing the phytic acid content in crops is desirable.Studies involving regulation of MIPS and IPK1 genes to generate low phytate rice have been reported earlier.However,the functional significance of OsITPK and the effect of its down-regulation on phytic acid content and the associated pleiotropic effects on rice have not yet been investigated.In this study,tissue specific RNA interference(RNAi)-mediated down-regulation of a major ITPK homolog(OsITP5/6K-1)resulted in 46.2%decrease in phytic acid content of T2 transgenic seeds with a subsequent 3-fold enhancement in the inorganic phosphorus content.Silencing of OsITP5/6K-1 altered the transcript levels of essential phytic acid pathway genes,without significantly affecting the transcript levels of other OsITPK homologs.Furthermore,the mapping of elements through X-ray microfluorescence analysis revealed significant changes in the spatial distribution pattern and translocation of elements in low phytate seeds.Additionally,low phytate polished seeds exhibited 1.3-fold and 1.6-fold enhancement in iron and zinc content in the grain endosperm,respectively.Silencing of OsITP5/6K-1 also altered the amino acid and myo-inositol content of the transgenic seeds.Our results successfully established that RNAi-mediated silencing of OsITP5/6K-1 gene significantly reduced the phytate levels in seeds without hampering the germination potential of seeds and plant growth.The present study provided an insight into the mechanism of phytic acid biosynthesis pathway.

Inaccuracies in Phytic Acid Measurement: Implications for Mineral Biofortification and Bioavailability

Biofortification of commonly eaten staple food crops with essential mineral micronutrients is a potential sustainable solution to global micronutrient malnutrition. Because phytic acid (PA;1,2,3,4,5,6-hexakis myo-inositol) reduces mineral micronutrient bioavailability, reduction of PA levels could increase the bioavailability of biofortified iron (Fe), zinc (Zn), calcium (Ca), and magnesium (Mg). PA is viewed as an anti-nutrient, yet PA and other inositol phosphates have also demonstrated positive health benefits. Phytic acid analysis in the agricultural, food, and nutritional sciences is typically carried out by colorimetry and chromatographic techniques. In addition, advanced techniques such as nuclear magnetic resonance and synchrotron X-ray absorption spectroscopy have also been used in phytic acid analysis. The colorimetric analysis may overestimate PA levels and synchrotron X-ray absorption techniques may not detect very low levels of inositol phosphates. This short communication discusses the advantages and disadvantages of each widely used phytic acid analysis method, and suggests high performance anion exchange (HPAE) chromatography with conductivity detection (CD) based analysis can achieve greater accuracy for the identification and quantification of inositol phosphates. Accurate characterization and quantification of PA and inositol phosphates will inform PA reduction and biofortification efforts, allowing retention of the benefits of non-phytic inositol phosphates for both plants and humans.

Quantification of Inositol Hexa-Kis Phosphate in Environmental Samples

Phosphorous (P) is a major contributor to eutrophication of surface waters, yet a complete understanding of the P cycle remains elusive. Inositol hexa-kis phosphate (IHP) is the primary form of organic (PO) in the environment and has been implicated as an important sink in aquatic and terrestrial samples. IHP readily forms complexes in the environment due to the 12 acidic sites on the molecule. Quantification of IHP in environmental samples has typically relied on harsh extraction methods that limit understanding of IHP interactions with potential soil and aquatic complexation partners. The ability to quantify IHP in-situ at the pH of existing soils provides direct access to the role of IHP in the P cycle. Since it is itself a buffer, adjusting the pH correspondingly alters charged species of IHP present in soil. Density Functional Theory (DFT) calculations support the charged species assignments made based pKas associated with the IHP molecule. Raman spectroscopy was used to generate pH dependent spectra of inorganic (PI) and IHP as well as (PO) from IHP and (PI) in soil samples. Electro-spray ionization mass spectroscopy (ESI-MS) was used to quantify IHP-Iron complexes in two soil samples using a neutral aqueous extraction.

膳食纤维与植酸对1,2-二甲肼诱导大鼠结直肠癌发生的作用

目的:考察膳食纤维与植酸对动物模型结直肠癌发生的作用。方法:用86只4w龄雄性Wistar大鼠,按体重随机分为纤维素组、果胶组、植酸组、纤维素+植酸组、果胶+植酸组和对照组六组,用1,2-二甲肼(DMH)皮下注射诱发结直肠癌,观察大鼠结直结直肠肿瘤的发生率、肿瘤的数量及体积;测定大鼠结肠粘膜细胞的增殖活性。结果:各组大鼠结直肠肿瘤的发生率与对照组相比无显著性差异,但植酸组平均每只鼠的肿瘤个数和肿瘤体积显著低于对照组;果胶组、果胶+植酸组平均每只鼠的肿瘤个数显著高于对照组。植酸组大鼠结直肠粘膜细胞的增殖活性比对照组显著降低。果胶组大鼠结直肠粘膜细胞的增殖活性比对照组显著升高。结论:膳食中添加果胶能增加诱癌大鼠患结直肠肿瘤的危险,而饮水中添加2%的植酸可降低诱癌大鼠患结直肠肿瘤的危险。

植酸制取的研究进展

植酸是所有植物种子的成分之一。植酸通常以混合态的Ca-Mg-K盐(即菲丁,Phytin)的形式存在于种子的不同部位。植酸的应用非常广泛。植酸的生产方法有两种:提取法与合成法。提取法制取植酸主要以农产品加工副产物如脱脂米糠、玉米浸渍水等为原料经分离、除杂、中和等工序制取;合成法主要是以非植酸化合物为原料(如六羟基苯、淀粉等)通过化学反应制得。目前合成法制取植酸的费用远远高于提取法制取植酸,所以一般采用提取法制取植酸。本文论述了现有提取法制取植酸的研究现状,并对现有生产工艺进行了分析,指出了今后提取法制取植酸的发展方向。

植酸酶在食品和医药方面的应用展望

从植酸及其盐类的抗营养作用出发,简单介绍了植酸酶的分类、来源,着重阐述了植酸酶在食品和医药方面应用及所面临的困难和应用前景。

三磷酸肌醇抗油脂氧化性的研究

本文通过在微波条件下 ,控制水解条件 ,当水解度达到 5 0 %时 ,将水解混和物通过装有 717型强阴离子树脂柱 ,并用 0 .0 5∽ 0 .7M的盐酸进行线性梯度洗脱 ,洗脱物分别取样消化 ,检测无机磷含量变化 ,并将同一峰值部分收集在一起 ,分离得到低磷酸肌醇各组分。各组分用HPLC和MS进行了确证。同时研究了三磷酸肌醇的抗油脂氧化活性。通过对菜籽色拉油在 6 0℃生化恒温箱中强化贮存 ,通过添加不同浓度的三磷酸肌醇 ,并用植酸 ,BHT作对照 ,用碘量法定期测定菜籽油的过氧化值 (POV值 ) ,用 2 ,4 -二硝基苯肼法测羰基值 ,并测定了酸值。实验发现三磷酸肌醇对菜籽油具有明显的抗氧化作用 ,但酸值有所升高。

微波辐射水解植酸快速制备肌醇的研究

采用微波辐射法水解植酸制备肌醇 ,缩短了水解时间和获得了较好的产率。用正交实验法确定了制备肌醇的最佳水解条件。

用小麦麸皮植酸酶制备三磷酸肌醇的研究

本文重点研究了从麸皮中提取植酸酶,并对其酶学性质进行了研究,其最佳酶活条件为pH5.15,温度为37℃。采用麸皮植酸酶部分水解植酸后,利用离子交换树脂分离得到了三磷酸肌醇。此法为磷酸肌醇的酶法制取提供了可行性方案。

应用常压水解法从脱脂米糠中制取肌醇

本文论述了应用常压水解从脱脂米糠制取肌醇的方法.用稀盐酸浸渍米糠,控制pH3—4,选用碳酸氢钠作沉淀剂,以稀植酸溶解菲汀,过滤,阳离子交换,减压浓缩得到植酸。取50—60％浓度的植酸,以1:1加入到一缩二乙二醇中,在130—150℃温度下水解,肌醇水解率在75—95％以上(以植酸汁).

肌醇六磷酸或(和)肌醇对多种癌细胞增殖影响

目的观察肌醇六磷酸（IP6）、肌醇（Ins）及两者合用对多种癌细胞增殖的抑制效果。方法取培养至对数生长期的人肝癌细胞Hep G2、人结肠癌细胞HT-29、人胃癌细胞7901、人乳癌细胞MCF-7和人肺癌细胞A549,接种于96孔板中,分别加入0.5、1.0、2.0、4.0 mmol/L的IP6、Ins及IP6＋Ins（1∶1,V/V）混合液,另设对照组（不加药物）。应用四甲基偶氮噻唑蓝（MTT）法测定不同浓度的IP6、Ins和两种药物合用作用于不同癌细胞48 h的抑制率,计算IP6、Ins及两种药物合用对不同癌细胞的半数抑制浓度（IC50）。结果与对照组比较,不同浓度的IP6、Ins及两种药物合用对5种癌细胞均能产生显著的抑制作用（F=8.253~15.292,t=6.871~8.537,P〈0.05）。不同浓度的IP6、Ins及两种药物合用对HT-29、7901、MCF-7、A549细胞抑制率差异无显著性（P〉0.05）;但在4.0mmol/L时,合用组对Hep G2细胞抑制效果显著高于IP6组和Ins组（F=7.462,P〈0.05）。IP6、Ins及两种药物合用作用于不同癌细胞的IC50比较,差异有显著性（F=6.792~17.694,P〈0.05）,其中Hep G2细胞和HT-29细胞的IC50值较低。结论 IP6、Ins及两种药物合用对不同癌细胞抑制效果不同,两种药物合用对5种癌细胞增殖抑制的增强作用不明显。

米糠深加工技术的分析与评价(Ⅰ)——米糠制油及脱脂米糠的利用

米糠富含脂质、蛋白质、矿物质、维生素等多种营养物质,是一种具有很大潜力的食品资源、化工原料和药物原料。对米糠制油技术及脱脂米糠的利用技术进行了综合性评述,为米糠的综合开发利用提供参考。

微波水解植酸制备三磷酸肌醇

A procedure for preparing of inositol triphosphate from sodium phytate was established.Hydrolysis was achieved by microwave rediation.When The hydrolysis rate of phytic acid was about 50%,the hydrolyzed solutions were pumped into a column containing 717 strong anion-exchange resin,then delivered a linear gradient of 0.05～0.7MNaCl.the samples of each tube were digested and the phosphate was determined.the contents of tubes corre-sponding to the same individual inositol phosphate were pooled together,and precipitated by Ca2+.The cacium salt was then turned into IP3.Neutralized with sodium bydroxide,rotary evaporated under vaccum,lyophilized,the desired product was gotten.Each inositol phosphate was identified by HPLC and MS.

酶法降解米糠中植酸的工艺研究

通过酶法降解米糠中植酸,植酸酶能将植酸及其二价盐类菲丁水解生成肌醇。以酶用量、酶解时间、p H值、酶解温度为影响因素,以代谢产物肌醇含量为判定依据进行单因素试验及正交试验以得出较优组合。通过试验得出四因素对植酸酶酶解植酸所得的肌醇含量的影响大小顺序为:酶用量>p H值>反应时间>反应温度,植酸最佳酶解条件为酶用量60 U/g,反应时间20 min,p H值4.0,反应温度55℃。验证试验测得肌醇含量为66.21 mg。酶解法反应条件温和、耗能低,为工业化生产提供了一种新的思路。

1，2，3-三磷酸肌醇抗肿瘤活性研究

目的研究小麦麸皮植酸酶催化植酸水解法所得1,2,3-三磷酸肌醇((1,2,3)InsP3)对荷瘤小鼠抗癌作用及免疫功能的影响。方法小麦麸皮植酸酶催化植酸部分水解,水解产物经分离得到(1,2,3)InsP3。采用小鼠S180移植瘤模型,以环磷酰胺(Cy)为对照,观察(1,2,3)InsP3对小鼠的抗肿瘤效果,并检测其对荷瘤小鼠免疫力的影响。结果(1,2,3)InsP3能抑制小鼠体内S180肿瘤生长,并能显著增强荷瘤小鼠胸腺指数、脾指数、过氧化氢酶(CAT)活力,脾细胞抗体生成能力。结论:(1,2,3)InsP3具有抑瘤和免疫调节作用。

从棉籽饼粕提取植酸制肌醇的工艺研究——棉籽饼粕的综合利用

在棉籽饼粕的综合利用中,饼粕经脱毒处理后,再提取植酸制备肌醇.脱毒后饼粕的游离棉酚含量为100PPM,可作动物饲料.植酸水解制肌醇的最优工艺条件用正交设计法确定,肌醇的得率可达55.8%.

植酸生产新工艺及应用

简述了从米糠或其它粮食副产物中提取植酸的最新工艺流程,与传统的生产工艺相比,总成本降低50%-60%,缩短了生产周期;最佳的工艺条件为:萃取剂浓度为0.05—0.10mol/L;萃取剂:米糠为6:1(w/w):终止最适宜pH3-3.4,萃取时间2h～3h。另外,对植酸在一些领域中的应用,如在医药、日用化工、食品、纺织、化学工业、金属加工和果蔬保鲜等方面作了详细介绍。发展植酸及其下游产品具有很好的应用价值和潜在的市场前景。

响应面分析法优化植酸合成工艺

采用肌醇为原料,以P2O5为磷化剂,通过磷化、合成、脱色、过滤制备植酸。在单因素试验的基础上,根据中心组合(Box-Benhnken)试验设计原理采用三因素三水平的响应面分析法优化植酸合成工艺条件,在分析各个因素的显著性和交互作用后,得到植酸合成最佳工艺条件:H2O与P2O5的反应摩尔比为2.1,合成温度174℃,合成时间3.3 h,其植酸含量最高为80.32%。