- Biosynthesis of a New Fusaoctaxin Virulence Factor in Fusarium graminearum Relies on a Distinct Path to Form a Guanidinoacetyl Starter Unit Priming Nonribosomal Octapeptidyl Assembly
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Fusarium graminearum is a pathogenic fungus causing huge economic losses worldwide via crop infection leading to yield reduction and grain contamination. The process through which the fungal invasion occurs remains poorly understood. We recently characterized fusaoctaxin A in F. graminearum, where this octapeptide virulence factor results from an assembly line encoded in fg3_54, a gene cluster proved to be involved in fungal pathogenicity and host adaptation. Focusing on genes in this cluster that are related to fungal invasiveness but not to the biosynthesis of fusaoctaxin A, we here report the identification and characterization of fusaoctaxin B, a new octapeptide virulence factor with comparable activity in wheat infection. Fusaoctaxin B differs from fusaoctaxin A at the N-terminus by possessing a guanidinoacetic acid (GAA) unit, formation of which depends on the combined activities of the protein products of fgm1-3. Fgm1 is a cytochrome P450 protein that oxygenates l-Arg to 4(R)-hydroxyl-l-Arg in a regio- and stereoselective manner. Then, Cβ-Cγ bond cleavage proceeds in the presence of Fgm3, a pyridoxal-5′-phosphate-dependent lyase, giving guanidinoacetaldehyde and l-Ala. Rather than being directly oxidized to GAA, the guanidine-containing aldehyde undergoes spontaneous cyclization and subsequent enzymatic dehydrogenation to provide glycociamidine, which is linearized by Fgm2, a metallo-dependent amidohydrolase. The GAA path in F. graminearum is distinct from that previously known to involve l-Arg:l-Gly aminidotransferase activity. To provide this nonproteinogenic starter unit that primes nonribosomal octapeptidyl assembly, F. graminearum employs new chemistry to process l-Arg through inert C-H bond activation, selective C-C bond cleavage, cyclization-based alcohol dehydrogenation, and amidohydrolysis-associated linearization.
- Chen, Dandan,Liu, Wen,Tang, Haoyu,Tang, Weihua,Tang, Zhijun,Wang, Wanqiu,Xue, Yufeng
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p. 19719 - 19730
(2021/11/30)
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- PROCESS FOR PREPARING GUANIDINO ACETIC ACID
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The present invention pertains to a process for preparing guanidino acetic acid (GAA) from cyanamide and glycine in alkaline process solution, in which anionic impurities are removed from the process solution by electrodialysis.
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Paragraph 0071-0075
(2020/07/16)
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- Clean production method of mercaptan compound
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The invention provides a clean production method of a mercaptan compound. There are two technological steps: Step 1, thiourea and halogenated hydrocarbon or active conjugated alkene react at 20-150 DEG C for 1-18 h, and after neutralization, S-alkylisothiourea is obtained; and Step 2, S-alkylisothiourea and aliphatic primary amine or secondary amine react at 20-180 DEG C for 1-24 h to obtain the mercaptan compound, and simultaneously, a substituted guanidino compound is coproduced. The mercaptan production technology has mild condition and high yield, hardly has discharge of ''three wastes (waste gas, waste water and industrial residue) '', and is a clean production method.
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Paragraph 0022
(2017/01/02)
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- Synthesis method for glycocyamine with high purity and high yield
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The invention discloses a synthesis method for glycocyamine with high purity and high yield. The synthesis method comprises the following steps: (1) adding glycine and a solvent into a reaction vessel, stirring at room temperature till glycine is dissolved completely, and adding liquid ammonia to adjust the pH value of the solution to be 10 to 11; (2) heating the mixed solution obtained in the step (1) to 55 to 60 DEG C, adding 50% hydrogen cyanamide aqueous solution into the reaction vessel slowly, stirring for 2 to 4 hours for reaction, carrying out vacuum suction filtration after the reaction is finished, and washing filter cake with filtrate to obtain a crude product of glycocyamine; (3) adding the crude product of glycocyamine obtained in the step (2) and DMF into another reaction vessel, heating to 30 to 40 DEG C, stirring for 0.5 hour, cooling to 0 DEG C, carrying out suction filtration, washing filter cake with DMF, and drying to obtain glycocyamine. The preparation method provided by the invention is simple in technology, short in production period, mild in reaction conditions, less in three wastes, high in product purity and yield, and relatively high in economical efficiency and environmental friendliness, thereby being suitable for industrialized production.
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Paragraph 0016
(2016/12/01)
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- Meteorites as catalysts for prebiotic chemistry
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From outer space: Twelve meteorite specimens, representative of their major classes, catalyse the synthesis of nucleobases, carboxylic acids, aminoacids and low-molecular-weight compounds from formamide (see figure). Different chemical pathways are identified, the yields are high for a prebiotic process and the products come in rich and composite panels.
- Saladino, Raffaele,Botta, Giorgia,Delfino, Michela,Di Mauro, Ernesto
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p. 16916 - 16922
(2014/01/06)
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- Molecular insights into the biosynthesis of guadinomine: A type III secretion system inhibitor
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Guadinomines are a recently discovered family of anti-infective compounds produced by Streptomyces sp. K01-0509 with a novel mode of action. With an IC50 of 14 nM, guadinomine B is the most potent known inhibitor of the type III secretion system (TTSS) of Gram-negative bacteria. TTSS activity is required for the virulence of many pathogenic Gram-negative bacteria including Escherichia coli, Salmonella spp., Yersinia spp., Chlamydia spp., Vibrio spp., and Pseudomonas spp. The guadinomine (gdn) biosynthetic gene cluster has been cloned and sequenced and includes 26 open reading frames spanning 51.2 kb. It encodes a chimeric multimodular polyketide synthase, a nonribosomal peptide synthetase, along with enzymes responsible for the biosynthesis of the unusual aminomalonyl-acyl carrier protein extender unit and the signature carbamoylated cyclic guanidine. Its identity was established by targeted disruption of the gene cluster as well as by heterologous expression and analysis of key enzymes in the biosynthetic pathway. Identifying the guadinomine gene cluster provides critical insight into the biosynthesis of these scarce but potentially important natural products.
- Holmes, Tracy C.,May, Aaron E.,Zaleta-Rivera, Kathia,Ruby, J. Graham,Skewes-Cox, Peter,Fischbach, Michael A.,Derisi, Joseph L.,Iwatsuki, Masato,Omura, Satoshi,Khosla, Chaitan
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p. 17797 - 17806
(2013/01/15)
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- An efficient approach to dispacamide A and its derivatives
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Dispacamide A and new analogs of this marine alkaloid were prepared in seven steps with an overall yield ranging from 12 to 33%. The key step of the strategy was a stereocontrolled Knoevenagel condensation under microwave dielectric heating in the last step. In this condensation, the 2-aminoimidazolin-4-one hydrochloride partners 10a-c were synthesized in three steps with good overall yields (33-79%) via the ring closure of N-guanidino acetic acids 9a-c and the aldehydes 5a,b as the two others building-blocks, in 3 steps with 60-66% overall yields. The six synthetic products have been obtained with a Z geometry about their exocyclic bond on the basis of 13C/1H long-range coupling constants using a gHSQMBC experiment.
- Guiheneuf, Solene,Paquin, Ludovic,Carreaux, Francois,Durieu, Emilie,Meijer, Laurent,Bazureau, Jean Pierre
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experimental part
p. 978 - 987
(2012/04/10)
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- PROCESS FOR STRAIGHTENING KERATIN FIBRES WITH A HEATING MEANS AND DENATURING AGENTS
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The invention relates to a process for straightening keratin fibres, comprising: (i) a step in which a straightening composition containing at least two denaturing agents is applied to the keratin fibres, (ii) a step in which the temperature of the keratin fibres is raised, using a heating means, to a temperature of between 110 and 250° C.
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- Preparation of N-formamidinylamino acids from amino and formamidinesulfinic acids
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A practical synthetic procedure for the conversion of amino acids into N-formamidinylamino acids using formamidinesulfinic acid in basic water solution is presented.
- Jursic,Neumann,McPherson
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p. 1656 - 1658
(2007/10/03)
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- Process for the manufacture of guanidines
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A process for the manufacture of a guanidine by amidination of a primary or secundary amine, which process comprises reacting the amine with a salt of 1-amidino-1,2,4-triazol with a strong acid.
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- A Facile Conversion of Amino Acids to Guanidino Acids
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The conversion of amino acids to guanidino acids by the action of aminoiminomethanesulfonic acids (2a-c) is reported.Compounds 2a-c were synthesized by peracetic acid oxidation of the corresponding thioureas.
- Miller, Audrey E.,Bischoff, Judith J.
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p. 777 - 779
(2007/10/02)
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- Methods and compositions for inducing resistance to bacterial infections
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A variety of substances are reported which alter host resistance to cocci and bacilli bacterial infections. Nevertheless, because of the extreme difficulty of total eradication, and the frequent reappearance of the same strains, even after their apparently successful elimination, there is a continuing need for drugs for the treatment of coccic infections. Certain guanidinoacylhistidines are effective in inducing resistance to infections due to cocci and bacilli.
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