- Zinc(II) complexes with amino acids for potential use in dermatology: Synthesis, crystal structures, and antibacterial activity
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The multifunctional profile of Zn2+ has influenced its great popularity in various pharmaceutical, food, and cosmetic products. Despite the use of different inorganic and organic zinc derivatives, the search for new zinc-containing compounds with a safer skin profile still remains an open issue. The present paper describes the synthesis, structural characterization, and antibacterial activity of zinc(II) complexes with proteinogenic amino acids as potential candidates for dermatological treatments. The obtained complexes are of the general formula [Zn(AA)2], where AA represents an amino acid (L-Glu, Gly, L-His, L-Pro, L-Met, and L-Trp). Their synthesis was designed in such a way that the final bis(aminoacidate) zinc(II) complexes did not contain any counter-ions such as Cl-, NO3-, or SO42- that can cause some skin irritations. The chemical structure and composition of the compounds were identified by 1H NMR spectroscopy and elemental analysis, and four were also characterized by single-crystal X-ray diffraction. The Hirshfeld surface analysis for the Zn2+ metallic center helped to determine its coordination number and geometry for each complex. Finally, the antibacterial properties of the complexes were determined with respect to three Gram-positive strains, viz. Staphylococcus aureus ATCC 6538, Staphylococcus epidermidis ATCC 12228, and Streptococcus pyogenes ATCC 19615, and two Gram-negative bacteria, viz. Escherichia coli ATCC 25992 and Pseudomonas aeruginosa ATCC 27853, and were compared with the activity of zinc 2-pirrolidone 5-carboxylate (ZnPCA), commonly applied in dermatology. It was found that the Zn(II) complexes with methionine and glycine exhibited a higher antibacterial activity than the tested standard, and the antimicrobial properties of complex with Trp were satisfactory. The results of the antimicrobial activity examination allow us to postulate that the obtained zinc complexes might become new active substances for use in dermatological products.
- Abendrot, Micha?,Ch?cińska, Lilianna,Felczak, Aleksandra,Kalinowska-Lis, Urszula,Kusz, Joachim,Lisowska, Katarzyna,Zawadzka, Katarzyna
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- An X-Ray Diffraction Study on the Structures of Mono(glycinato)zinc(II) and Tris(glycinato)zincate(II) Complexes in Aqueous Solution
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The structure of zinc(II) complexes with glycinate ion in solution was investigated by the X-ray diffraction method.The measurements were performed at 20 deg C for the solutions with the Cgly/CZn mole ratios of 1.49 (solution A) and 5.09 (solution B), where Ci denotes the total concentration of species i.From the analysis of the radial distribution curve of solution A, in which comparable amounts of the hexaaqua- and mono(glycinato)zinc(II) complexes existed, it was found that the mono(glycinato)zinc(II) complex combined with four water molecules at the distance of (2.12+/-0.01) Angstroem.The Zn-OH2 bond length within the complex was longer than that within the hexaaquazinc(II) ion (2.08 Angstroem).The Zn-O and Zn-N distances, where O and N denote oxygen and nitrogen atoms within the glycinate ion in the + complex, were both (2.12+/-0.02) Angstroem.Thus the mono(glycinato)zinc(II) complex had a regular octahedral structure.The nonbonding Zn...C distance was found to be (2.84+/-0.02) Angstroem.The X-ray diffraction data of solution B, which contained the - ion as a predominant species, showed that the tris(glycinato)zinc(II) complex had a regular octahedral structure with the both Zn-O and Zn-N bond distances of (2.12+/-0.01) Angstroem.The nonbonding Zn...C(COO), Zn...C(CH2), and Zn...O(O=C) lengths were (2.87+/-0.03) Angstroem, (2.93+/-0.03) Angstroem, and (4.10+/-0.04) Angstroem, respectively.The solubility of the bis(glycinato)zinc(II) complex was so low that the structural determination of the complex by the present X-ray diffraction method was not possible.
- Ozutsumi, Kazuhiko,Ohtaki, Hitoshi
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- ENERGY-EFFICIENT SOLVENT-FREE METHOD FOR PRODUCING METAL CHELATES
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The invention relates to a method for producing, amongst other things, amino-acid and/or hydroxycarboxylic-acid metal chelates, a solvent-free mixture of at least one metal oxide, metal hydroxide, metal carbonate or oxalate, and the solid organic acid is subjected to intensive mechanical stress. According to the invention, this is done in that the reaction partners are introduced in particle form into a fluid stream of a fluid-bed countercurrent mill operating without grinding elements, wherein mechanical activation of at least one of the reaction partners is effected by collision processes within a reaction chamber formed in a region of the fluid stream, and a solid body reaction to form the metal chelate is triggered. The novel method operates very energy-efficiently and with a high specific yield. It leads to a product having compact particles in the small, single-digit micrometer range having a comparatively narrow particle size distribution and a large surface. The product is homogenous and very pure. Thermal loading or decomposition of the organic chelate ligands, in particular of the amino acids, is likewise avoided, as are contaminants from milling and grinding element abrasion.
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Paragraph 0083; 0090
(2021/10/11)
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- METAL COMPLEXES
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The disclosure provides metal complexes which have improved stability in the presence of humidity. The disclosure also provides a method of making metal complexes and uses thereof.
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Paragraph 0047
(2018/06/29)
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- METHOD FOR THE PRODUCTION OF METAL CARBOXYLATES AND THE METAL AMINOATE OR METAL HYDROXY ANALOGUE METHIONATE DERIVATIVES THEREOF, AND USE OF SAME AS GROWTH PROMOTERS IN ANIMAL FEED
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A method of production of metal carboxylates and of their metal carboxylate-aminoate or metal carboxylate-methioninate hydroxy analog derivatives, and their use as growth promoters in animal nutrition. It comprises mixing stoichiometric quantities of formic or butyric acid and oxide and of the dry basic salt of divalent metal, the oxide or hydroxide of Zn2+ or Cu2+, to give an exothermic reaction, without addiction of solvents, giving rise to a dry carboxylate of divalent metal that is easy to use. It also describes the use of a stage of mixing with metal aminoates or hydroxy analogs of methionine in the process, for forming either a carboxylate-aminoate of divalent metal or a carboxylate-methioninate hydroxy analog of divalent metal, products that are finally obtained in a dry form that is easy to use. Finally it describes the use of the compounds that can be obtained in the feeding of monogastric animals for improving the productivity, the bioavailability of the metals, and achieve a reduction of their emission to the environment, owing to the growth-promoting effect that they all display.
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Page/Page column 6-7
(2008/06/13)
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- Hypoallergenic metal amino acid chelates and metal amino acid chelate-containing compositions
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Hypoallergenic metal amino acid chelate compositions, hypoallergenic formulations containing hypoallergenic metal amino acid chelates, methods of preparing hypoallergenic metal amino acid chelate, and methods of administering hypoallergenic metal amino acid chelates are provided. Specifically, the present invention provides metal amino acid chelates that are substantially free of allergens such that administration of the metal amino acid chelates to a subject in an effective amount to cause a medicinal or nutritional result does not produce a discernable adverse allergic reaction. The metal amino acid chelates can include chelates having a naturally occurring amino acid to metal molar ratio of from about 1:1 to 4:1.
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Page/Page column 7
(2008/06/13)
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- Clear antiperspirant gel stick and method for making same
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A residue free, antiperspirant gel stick composition is disclosed which comprises an antiperspirant compound which is soluble in a diol, a normally liquid, water soluble diol, a gelling agent and a zinc glycinate in amount sufficient to control the pH of the gel stick at about 4.1 to about 5.0, the glycine to zinc mole ratio of the zinc glycinate added being about 2.0/1 to about 3.0/1. The process for preparing a diol soluble antiperspirant active useful in preparing the residue free gel stick is also disclosed and comprises reacting an antiperspirant compound with a water soluble, normally liquid diol in a water solution by heating for about 1 to about 100 hours at a temperature of about 50° C. to about 110° C.; adding a zinc glycinate to the reaction mixture and removing the water to recover a powdered antiperspirant active.
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- Deodorant composition
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Zinc glycinate as a non-irritating effective deodorant which chemically neutralizes odoriferous compounds and inhibits bacterial growth; deodorant compositions containing zinc glycinate as anhydrous or hydrated bis(glycino) - zinc salt; and methods of deodorizing the body by application to sweat areas. The present invention relates to zinc glycinate as a deodorant active material having the dual function of chemically neutralizing body odors and inhibiting bacterial growth, particularly gram negative bacteria.
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