- Crystal structure and thermodynamic properties of the coordination compound calcium D-gluconate Ca[D-C6H11O7]2(s)
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The coordination compound calcium D-gluconate, Ca[D-C6H11O7]2(s), was synthesized and characterized by chemical analysis, elemental analysis, and X-ray crystallography. Single crystal X-ray diffraction technique revealed that the compound was formed by two D-gluconate anions and one calcium (II) cation. And the D-gluconate anion had a curved chain configuration with an intramolecular bond. The compound exhibited an outstanding chelate property of D-gluconate anions to calcium (II) cations, and the calcium (II) cation was eight-coordinated and chelated by four D-gluconate anions. The lattice potential energy and ionic volume of the anion were calculated to be 1434.05 kJ?mol?1 and 0.4211 nm3 from crystallographic data. In accordance with famous Hess law, a reasonable thermochemical cycle was designed and the standard molar enthalpy of formation of Ca[D-C6H11O7]2(s) was calculated as ΔsHm[Ca[D-C6H11O7]2, s] = -(3545.19 ± 1.07) kJ?mol?1 by use of an isoperibol solution-reaction calorimeter. Furthermore, molar heat capacities of the compound were measured using a Quantum Design Physical Properties Measurement System (PPMS) with specific heat option within the temperature range from (1.9–300) K. The heat capacities of the compound increased with the temperature and no thermal anomaly was found in the whole temperature region. The experimental data was fitted to a function of the absolute temperature T with a series of theoretical and empirical models for the proper temperature ranges. The values of standard thermodynamic function, Cp,mo/J?K?1?mol?1, Δ0THmo/kJ?mol?1, Δ0TSmo/J?K?1?mol?1, and ΔoTGmo/T/J?K?1?mol?1 (=Δ0TSmo-Δ0THmo/T) from T = (0–300) K was calculated based on the fitting results. The standard molar heat capacity, entropy and enthalpy of the compound at T = 298.15 K and 0.1 MPa was determined to be Cp,mo= (493.20 ± 2.70) J·K?1 mol?1, Hmo= (75934 ± 805) J·mol?1, Smo= (471.55 ± 2.78) J·K?1 mol?1, and Gmo/T = - (64658 ± 808) J·K?1?mol?1, respectively.
- Di, You-Ying,Kong, Yu-Xia,Liu, Yu-Pu,Zhang, Guo-Chun,Zhou, Chun-Sheng
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- Calcium gluconate dihydrate
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The invention discloses a calcium gluconate dihydrate and a preparation method thereof. When the calcium gluconate dihydrate is determined by a powder X-ray diffraction method, characteristic diffraction peaks are shown at places with 2theta+/-0.2 degree diffraction angles of 8.03 degrees, 9.06 degrees, 17.30 degrees, 20.78 degrees and 22.47 degrees. The calcium gluconate dihydrate prepared by themethod has the advantages of good thermal stability, fast dissolution speed in water and high content. In addition, the preparation method is simple in process, high in yield and high in repeatability, and is suitable for industrial production.
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Paragraph 0037-0051
(2020/01/25)
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- Preparation method of calcium glucarate
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The invention relates to a preparation method of calcium glucarate, and belongs to the field of pharmacy. The invention provides a preparation method of the calcium glucarate. The preparation method comprises the following steps: (1) putting glucose, oxygen and a metal catalyst palladium vanadium ammonium into a high-pressure reactor for catalytic oxidation reaction to obtain glucaric acid; (2) after the oxidation reaction, adding potassium-containing alkali to convert the glucaric acid into potassium gluconate; (3) enabling the potassium gluconate to react with an acid to release the glucaricacid; (4) enabling the glucaric acid to react with the calcium-containing alkali to obtain the calcium glucarate. The preparation method disclosed by the invention is pollution-free to the environment, and meanwhile, the total yield is increased; the catalyst can be repeatedly used; the cost is reduced; the calcium content is 98 to 102 percent; a small amount of industrial wastewater, waste residues and waste gas are generated; the preparation method is suitable for industrial production.
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Paragraph 0051-0054
(2019/05/08)
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- Electrodialytic purification of calcium gluconate
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Possibility of using the electrodialytic method for purification of calcium gluconate to remove sodium bromide was examined. The electrodialysis conditions were optimized. Pleiades Publishing, Ltd., 2012.
- Konarev
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experimental part
p. 225 - 228
(2012/08/08)
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- BIOLOGICALLY ACTIVE FOOD ADDITIVE FOR THE PROPHYLAXIS OF OSTEOPOROSIS DISEASE
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The invention relates to biologically active food supplements and is intended for preventive action against the states associated with osteoporosis. The technical effect consists in providing a biologically active food supplement which sustains a normal testosterone level in the body, ensures an efficient assimilation of calcium by the body and retention of calcium in the bony tissue for a prolonged time enabling thereby the prevention of osteoporosis.
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- Deoxyiminoalditols from aldonolactones; I. Preparation of 1,4-dideoxy-1,4-iminohexitols with D- and L-allo and D- and L-talo configuration: Potential glycosidase inhibitors
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1,4-Dideoxy-1,4-iminohexitols were prepared by a convenient two-step reaction from 2,6-dibromo-2,6-dideoxyhexono-1,4-lactones by treatment with aqueous ammonia and subsequent reduction of the carboxy function with sodium borohydride. By interchange of the reactions, the dibromolactones were reduced to 2,6-dibromohexitols, which by reaction with aqueous ammonia yielded the same imino compounds. Thus, from 2,6-dibromo-2,6-dideoxy-D-mannono- (1) and -D-glucono-1,4-lactone (9) the 1,4-dideoxy-1,4-imino-L-allitol (6) and -D-talitol (14) were prepared, respectively. These two compounds were also obtained from 2,6-dibromo-2,6-dideoxy-D-mannitol (5) and -D-glucitol (13), respectively, by reaction with aqueous ammonia. The enantiomeric 1,4-dideoxy-1,4-imino-D-allitol (18) and -L-talitol (22) were prepared similarly from the new 2,6-dibromo-2,6-dideoxy-L-mannono- (16) and -L-glucono-1,4-lactone (20), via the dibromo-L-hexitols 17 and 21, respectively. The ring closure of the dibromo compounds with ammonia has been shown to proceed via epoxides.
- Lundt,Madsen
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p. 714 - 720
(2007/10/02)
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- Glycoside hydrolysis
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The invention provides a process for preparing L--rhamnose by hydrolysing glycosidic bonds in a glycoside having rhamnose in a terminal position by heating in an aqueous solution of an organic carboxylic acid at a pH between 1 and 3. Preferably the organic carboxylic acid is acetic acid, propionic acid, citric acid or malic acid in the form of a solution of the organic acid contains 0.1-25% (w/w) of organic acid. Also the glycoside can be used in the form of crude citrus material.
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- Preparation of metal gluconates
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A metal gluconate is prepared from a supersaturated solution of the gluconate in an aqueous solution having a pH between about 4 and about 7, the degree of supersaturation with respect to the metal gluconate being of at least about 1.3, by introducing seed crystals into the solution and removing water at a temperature in excess of 50°C to crystallize the dissolved metal gluconate, while maintaining the supersaturation. The resulting crystals are agitated to further crystallize dissolved metal gluconate and the crystallized gluconate is then recovered.
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- New N-typed crystals of calcium gluconate
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N-typed crystal of calcium gluconate having a powder X-ray diffraction pattern as shown in Fig. 4 and a process for the preparation thereof which comprises precipitating calcium gluconate from an aqueous conventional calcium gluconate solution having the property that conventional crystals of calcium gluconate are not precipitated therefrom at around 40°C, at below 20°C.
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