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The Principle of Polysaccharide Gels

Advances in Bioscience and Biotechnology 2015年第1期6卷 22-36页

作者： masakuni tako Department of Subtropical Bioscience and Biotechnology University of the Ryukyus Nishihara Okinawa Japan Present Address: Health and Longevity Research Laboratory Integrated Innovation Research Center University of the Ryukyus Nishihara Okinawa Japan

For several decades attention has been directed to natural polysaccharide gels and synthesized polymer gels. The structure-function relationships at molecular level in water of polysaccharides, κ-carrageenan, ι-carrageenan, agarose (agar), and gellan family of polysaccharides (gellan, welan, rhamsan, S-657, deacetylated rhamsan and native gellan gum), which are industrially useful polysaccharides extracted from family of red seaweeds and bacteria, in principle are discussed on the view point of rheological aspects. The polysaccharide molecules (0.1% - 1.0%) play a dominant role in the center of the tetrahedral cavities occupied by water molecules (99.0% - 99.9%), and the arrangement is similar to a tetrahedral structure in a gelation process. The cage and hydrophobic effect play thermal dynamically dominant role in gelation process which gives lowest entropy to electrons of sugar residues. Though the chemical structure of these polysaccharides similar each other, their rheological (gelling) characteristics are quite different. Many investigations about the gelling properties of the polysaccharides have been undertaken to elucidate the structure-function relationship, but no other researchers have established mechanism at the molecular level. There is consistency in our investigations. Thus, the rheological analysis is one of significant methods for understanding the structure-function relationship of polysaccharides in aqueous media. The discussion provides many important information not only in academic field, but also in industrial one, such as food, cosmetic, pharmaceutical, drug delivery and tissue industries, and biotechnology.

关键词： Polysaccharide Gels Principle Gelation Mechanism of Polysaccharides Hydrogen Bonding Ionic Bonding Van der Waals Forces of Attraction

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Discovery of Unusual Highly Branched Galactomannan from Seeds of <i>Desmanthus illinoensis</i>

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Journal of Biomaterials and Nanobiotechnology 2018年第2期9卷 101-116页

作者： masakuni tako Yukihiro Tamaki Takeshi Teruya Department of Bioscience and Biotechnology University of the Ryukyus Okinawa Japan Health and Longevity Research Laboratory Okinawa Japan Laboratory of Vaccinology and Vaccine Immunology Center of Molecular Bioscience University of the Ryukyus Okinawa Japan

A galactomannan was isolated from seeds of a leguminous plant, Desmanthus illinoensis, which is grown in Okinawa, Japan. D-Galactose (molar ratio, 1.0) and D-mannose (0.82) were identified via High-performance Anion Exchange Chromatography Coupled with a Pulse Amperometric Detector. The molecular mass and specific rotation were estimated to be 1000 kDa and +53.8°, respectively. The infrared spectrum indicated that the galactomannan was involved in both α- and β-linkages, and two types of α-linkages were detected at 814 and 830 cm-1. The 1H- and 13C-NMR spectra indicated that the majority of the β-D-mannan main chain was substituted with mono α-D-galactose or α-D-galacto-disaccharide-side chains. Methylation analysis was used to identify 2,3,4,6-tetra-O-methyl-D-galactose (molar ratio, 3.3), 2,3,4-tri-O-methyl- D-galactose (1.0) and 2,3-di-O-methyl-D-mannose (3.1). Specifically, unique 2,3,4-tri-O-methyl D-galactose residue was identified from mass spectrum. The results suggested that the galactomannan was 1,4-linked-β-D-mannan substituted with α-D-galactose or 1,6-linked-α-D-galacto-disaccharide side chains at C-6 on the main chain. The galactomannan isolated from D. illinoensis was an unusual highly branched polysaccharide, and its chemical structure was proposed. This work is the first to report on the galactomannan involving 1,6-linked α-D-galacto-disaccharide side chains in addition to α-D-galactose mono side chains.

关键词： Unusual Highly Branched Galactomannan Desmanthus illinoensis NMR Analysis Methylation Analysis Chemical Structure

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The Novel Pyruvated Glucogalactan Sulfate Isolated from the Red Seaweed, Hypnea pannosa

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Advances in Biological Chemistry 2016年第3期6卷 114-125页

作者： masakuni tako Rintaro Ohtoshi Kazutaka Kinjyo Shuntoku Uechi Department of Subtropical Bioscience and Biotechnology University of the Ryukyus Okinawa Japan Health and Longevity Research Laboratory Integrated Innovation Research Center University of the Ryukyus Okinawa Japan

The polysaccharide was isolated from Hypnea pannosa which was grown in Okinawa, Japan. The yield of the polysaccharide was 17.2%, and the total carbohydrates, pyruvic acid, sulfuric acid and ash contents were 55.2%, 3.8%, 35.2% and 24.3%, respectively. 3,6-Anhydro-α-D-galactose, β-D-galactose, α-D-galactose and D-glucose were identified by liquid and thin-layer chromatography. Fourier transform infrared (FTIR) spectra of the polysaccharide resembled that of ι-carrageenan. From the 1H- and 13C-NMR spectra, 1,3-linked β-D-galactose, 1,4-linked anhydro-α-D-galactose, 1,4-linked α-D-galactose, 1,4-linked β-D-glucose and pyruvic acid (carboxyl acetal, methyl proton and methyl carbon) were assigned. Methylation analysis revealed terminal D-galactose 0.1 mol), 1,4-linked D-glucose (1.0 mol) and 1,2,3,4,6-linked D-galactose (3.7 mol) for native polysaccharide, and terminal D-galactose, 1,4-linked D-galactose (1.9 mol), 1,4-linked D-glucose (1.0 mol), 1,3- linked D-galactose (1.7 mol), and 1,3,4,6-linked D-galactose (0.3 mol) which substituted with pyruvate group at 4 and 6 positions for desulfated polysaccharide. The polysaccharide was the novel pyruvated glucogalactan sulfate, the structure of which was proposed.

关键词： Hypnea pannosa Pyruvated Glucogalactan Sulfate 1H- and 13C-NMR Analy-sis Methylation Analysis Chemical Structure

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Structure of Ulvan Isolated from the Edible Green Seaweed, Ulva pertusa

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Advances in Bioscience and Biotechnology 2015年第10期6卷 645-655页

作者： masakuni tako Makie Tamanaha Yoshiyuki Tamashiro Shuntoku Uechi Department of Subtropical Bioscience and Biotechnology University of the Ryukyus Nishihara Okinawa Japan Health and Longevity Science Research Laboratory Integrated Innovation Research Center University of the Ryukyus Nishihara Okinawa Japan

Ulvan, rhamnan sulfate, was extracted from the edible green seaweed, Ana-aosa (Ulva pertusa), which is grown on the coast of the Okinawa Islands. The yield of ulvan was 8.5% (W/W), and the total carbohydrates, uronic acid and sulfuric acid and ash contents were 67.3%, 23.8%, 19.7% and 22.6%, respectively. L-Rhamnose, D-xylose and D-glucose residues were identified by liquid chromatography, and their molar ratio was 4.0:0.1:0.3. D-Glucuronic and L-idulonic acid residues were also identified in molar ratio of 1.0:0.2. The NMR (13C and 1H) and methylation analysis revealed terminal β-D-glucruonic acid, terminal α-L-idulonic acid, 1,3-linked α-L-rhamnose, 1,4-linked α-L-rhamnose, 1,2,4-linked α-L-rhamnose, 1,3,4-linked α-L-rhamnose, 1,2,3,4-linked α-L-rhamnose and 1,3,4-linked β-D-xylose. The sulfate groups were attached at the C-2 and C-3 positions of the 1,4-linked α-L-rhamnose as well as C-3 of the 1,4-linked β-D-xylose residues. The chemical structure of the ulvan from Ulva pertusa was determined.

关键词： Ulva pertusa Ulvan NMR Analysis Methylation Analysis Chemical Structure

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The Principles of Starch Gelatinization and Retrogradation

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Food and Nutrition Sciences 2014年第3期5卷 280-291页

作者： masakuni tako Yukihiro Tamaki Takeshi Teruya Yasuhito Takeda Department of Biochemical Science and Technology Kagoshima University Kagoshima Japan. Department of Subtropical Bioscience and Biotechnology University of the Ryukyus Nishihara Japan Department of Subtropical Bioscience and Biotechnology University of the Ryukyus Nishihara Japan Health and Longevity Research Laboratory Integrated Innovation Research Center University of the Ryukyus Nishihara Japan

The polysaccharides, such as κ-carrageenan, ι-carrageenan, agarose (agar), gellan gum, amylose, curdlan, alginate, and deacetylated rhamsan gum, in water changed into an ice-like structure with hydrogen bonding between polymer and water molecules, and between water-water molecules even at a concentration range of 0.1% - 1.0% (W/V) at room temperature, resulting in gelation. Such dramatic changes from liquid into gels have been understood at the molecular level in principles. In this review, we describe the structure-function relationship of starch on the view point of rheological aspects and discuss gelatinization and retrogradation mechanism including water molecules at molecular level. The starch molecules (amylose and amylopectin) play a dominant role in the center of the tetrahedral cavities occupied by water molecules, and the arrangement is partially similar to a tetrahedral structure in a gelatinization process. The arrangement should lead to a cooperative effect stabilizing extended regions of ice-like water with hydrogen bonding on the surface of the polymer molecules, where hemiacetal oxygen and hydroxyl groups might participate in hydrogen bonding with water molecules. Thus, a more extended ice-like hydrogen bonding within water molecules might be achieved in a retrogradation process. Though many investigations not only include starch gelatinization and retrogradaion, but also the gelling properties of the polysaccharides have been undertaken to elucidate the structure-function relationship, no other researchers have established mechanism at the molecular level. There is reasonable consistency in our investigations.

关键词： Principles Starch Amylose Amylopectin Hydrogen Bonding Gelatinization and Retrogradation Mechanism

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Structure-Function Relationship of a Gellan Family of Polysaccharide, S-198 Gum, Produced by Alcaligenes ATCC31853

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Advances in Biological Chemistry 2016年第3期6卷 55-69页

作者： masakuni tako Seiko kitajima Takuya Yogi Keiko Uechi Masayuki Onaga Yukihiro Tamaki Shuntoku Uechi Department of Subtropical Bioscience and Biotechnology University of the Ryukyus Okinawa Japan Health and Longevity Research Laboratory Integrated Innovation Research Center University of the Ryukyus Okinawa Japan

The structure-function relationship of a gellan family of polysaccharides, S-198 gum produced by Alcaligenes ATCC31853 was investigated in terms of rheological aspects. The flow curves of S-198 gum showed plastic behavior above 0.3%. Gelation did not occur in S-198 gum solution at low temperature (0℃), even at 0.8%. Both the viscosity and the elastic modulus remained constant with increasing temperature up to 80?C. The elastic modulus decreased a little with the addition of CaCl2 (6.8 mM), but then once again remained constant up to 80℃. The highest elastic modulus was observed for deacylated gellan gum with the addition of CaCl2 and increased slightly with increasing temperature up to 80℃, which was considered to be a transition temperature, after which it decreased rapidly. The elastic modulus of S-198 gum in the presence of urea (4.0 M) was lower than that in aqueous solution at low temperature (0℃), but remained constant with increasing temperature up to 80℃. The intramolecular associations, (hydrogen bonding and van der Waals forces of attraction), of S-198 gum molecules in aqueous solutions were proposed. The gellan family of polysaccharides, S-198, S-88, S-657, rhamsan, welan and gellan gum, provided a good opportunity to investigate the structure-function relationship for polysaccharides.

关键词： S-198 Gum Alcaligenes ATCC31853 Thermal Stability Intramolecular Associations Gellan Family of Polysaccharide

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Fine nie

引用

中学生博览 2009年第20期 26-27页

作者： tako

天已经很黑了，我披头散发地，依偎在墙角，空洞的屋子，只有我轻声而又急促的呼吸，也没有时针烦人的走动声——是的，嫌它太吵。前天夜里，沫来我这里，我向来很反感别人走进我屋子里的，我怕会打破这神秘的幽静。不过，这次，我破例... 详细信息

天已经很黑了，我披头散发地，依偎在墙角，空洞的屋子，只有我轻声而又急促的呼吸，也没有时针烦人的走动声——是的，嫌它太吵。前天夜里，沫来我这里，我向来很反感别人走进我屋子里的，我怕会打破这神秘的幽静。不过，这次，我破例。沫很安静地踩着楼梯上来，凭着淡淡的烛光看到我。

关键词：中学课外阅读阅读材料《Fine nie》

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铂基催化剂用于柴油烃氧化(英文)

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催化学报 2011年第5期32卷 777-781页

作者： Masaaki HANEDA Motoi SASAKI Hideaki HAMADA masakuni OZAWA Ceramics Research Laboratory Nagoya Institute of Technology Research Center for New Fuels and Vehicle Technology National Institute of Advanced Industrial Science and Technology(AIST)

The catalytic performance of Pt-based catalysts for the total oxidation of hydrocarbons was *** activity of supported Pt catalysts(Pt/Al2O3,Pt/ZrO2,Pt/TiO2,and Pt/H-ZSM-5)depends on the metal oxide ***/Al2O3 showed the highest catalytic activity when the catalysts were aged at 750°C for 50 h in *** activity of Pt/Al2O3 was dependent on the valence state of the Pt ***/Al2O3 with the Pt surface in the metallic state was more active than with the surface in the cationic *** surface density of acid and basic sites on the Al2O3 support controlled the valence state of the Pt surface and stability of the Pt particles in the highly dispersed state,respectively.

关键词： diesel oxidation catalyst platinum alumina valence state of platinum surface surface acid-base property

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Two Algorithms of Power Loading for MCM System in Nakagami Fading Channel

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International Journal of Communications, Network and System Sciences 2010年第2期3卷 208-211页

作者： Lev GOLDFELD Vladimir LYANDRES Lior tako 不详

We consider two non-iterative algorithms of adaptive power loading for multicarrier modulation (MCM) system, The first one minimizes the average power of the system transmitter and ensures the preset average bit-error rate, while the second reduces the average transmitting power subject to the given values of demanded bit-error rate and of the outage probability. The algorithms may be used for power-efficient management of the up-link in cellular communication, where mobile terminals use rechargeable batteries, or of the downlink in satellite communication with solar power source of a transponder. We present performance analysis of the adaptive MCM systems supported by computer simulation for the case of the m-Nakagami fading and additive white Gaussian noise in the forward and backward channels. Evaluation of the power gain of the proposed strategies and its comparison with uniform power loading shows that the gain depends on the fading depth and average signal to noise ratio in the system sub-channels.

关键词： MCM Fading Channel Adaptive Power Loading

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马拉维北部农村青少年母亲产后护理利用的决定因素评估

马拉维北部农村青少年母亲产后护理利用的决定因素评估

引用

作者： Glad tako Mzomera Ngwira 江苏大学

学位级别：硕士

尽管在全球一级取得了很大进展,但产妇死亡率仍然是一项公共卫生挑战,世界社会边缘化和弱势群体不断面临这一挑战。农村环境中的青春期母亲就是这样一个边缘化和易受伤害的群体,对孕产妇死亡率造成很大影响。尽管有充分的证据表明,产后... 详细信息

尽管在全球一级取得了很大进展,但产妇死亡率仍然是一项公共卫生挑战,世界社会边缘化和弱势群体不断面临这一挑战。农村环境中的青春期母亲就是这样一个边缘化和易受伤害的群体,对孕产妇死亡率造成很大影响。尽管有充分的证据表明,产后护理服务在减少产妇死亡方面发挥着关键作用,但在低收入和中等收入国家的青少年母亲中,产后护理服务的利用率通常很低。在这一背景下,研究的主要目的是评估马拉维北部农村地区青少年母亲利用产后护理服务的决定因素。这是一项基于社区的横断面研究,在Mzimba北部地区的三（3）个农村医疗机构进行。本研究采用多阶段抽样技术,对586名在研究前两年内分娩的青少年母亲进行了抽样调查。采用访谈法进行问卷调查,并运用频数分布和logistic回归进行分析。显著性水平建立在95%置信水平。研究结果显示,适当的产后护理服务利用率为40%。这意味着大多数参与者没有达到世卫组织建议的四次产后访视。研究结果显示,年龄、胎次、婚姻状况、职业、教育程度、家庭/家庭收入以及到医疗机构的距离与产后护理利用率有关。除此之外,研究发现,产科并发症、剖腹产和阴道出血与青少年母亲的产后护理利用率有更显著的相关性。因此。研究得出结论,需要因素是青少年母亲PNC利用的最重要决定因素。因此,研究建议加强提供关于产后护理服务和可能的产后产科危险迹象的信息教育和交流,鼓励母亲在分娩后重返学校,鼓励男性伴侣之间的教育,赋予母亲权力并鼓励母亲继续教育参与决策,尤其是在影响自身健康的事情上。政府还应确保向社区内的家庭提供合理距离内的卫生设施。

关键词：孕产妇保健孕产妇死亡率产后保健利用率青春期母亲

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