- Influence of Sulfoxide Group Placement on Polypeptide Conformational Stability
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The synthesis of a homologous series containing five new nonionic sulfoxide containing polypeptides was described. Sulfoxide groups bestowed water solubility for all homologues, which allowed their use as a model for study of helix-coil transitions in water while avoiding contributions from charged groups or phase separation. Polypeptides were found to adopt chain conformations in water that were dependent on distance of sulfoxides from chain backbones, overall side-chain lengths, and solvent. These results allow preparation of polypeptide segments with different chain conformations without changing chemical functionality for potential use in structural studies and functional applications.
- Gharakhanian, Eric G.,Bahrun, Ehab,Deming, Timothy J.
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supporting information
p. 14530 - 14533
(2019/10/02)
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- Derivative of Kutkin dimer analog JJA-D0 or its pharmaceutically acceptable salt, preparation method and use thereof
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The invention relates to a derivative of Kutkin dimer analog JJA-D0 or its pharmaceutically acceptable salt, a preparation method and use thereof. The compound has a structure shown as a general formula (I). According to the invention, an alkyl group, an aryl group, a heteroaryl group, an alkoxycarbonylalkyl group, an acyl group, a sulfonate group, an antioxidant group such as a lipoic acid group,a H2S donor group such as a cysteine group, and a NO donor group such as a nitrate group are introduced to JJA-D0, and a series of structurally novel compounds can be synthesized and disclosed. The compounds inhibit NADPH oxidase and have superior anti-oxidation and anti-inflammatory pharmacological mechanisms by comparing with Kutkin, the compounds also have donor groups that provide NO and H2S,can further enhance pharmacological activity, and can be a new class of multifunctional compounds. The disclosed JJA-D0 derivative can be used for preparing health products or drugs for prevention ortreatment of diseases associated with NADPH oxidase, diseases associated with free radicals, diseases associated with inflammation, diseases associated with NO, and diseases associated with H2S.
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Paragraph 0111-0112
(2019/01/08)
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- A step-by-step crystallization for preparing thio alkyl/alkenyl cysteine sulfoxide method
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The invention discloses a method for preparing thioalkyl/alkenyl cysteine sulfoxide by fractional crystallization, belonging to the technical field of compound preparation. The method comprises the following steps: adding cysteine or cysteine salts, a sodium hydroxide solution and an R group (alkyl or alkenyl)-derived material into absolute ethanol in sequence for reaction to synthesize coarse ACSs, re-crystallizing ACSs, purifying, oxidizing to form ACSOs, and fractionally crystallizing to obtain natural dextrorotatory ACSOs, wherein the R group-derived material is replaced to synthesize different types of ACSOs in allium; enantiomers in racemes are separated by adopting the fractional crystallization method to obtain natural dextrorotatory ACSOs with optical activity. Compared with a conventional extraction method, the method has the characteristics that the yield and the purity are high, a conventional complicated extraction process is avoided, the product has the optical activity, and the physical property is close to that of natural extract; the product is used in the fields of health products, pharmaceuticals and the like, the effects of resisting bacteria and cancers, reducing blood fat and the like of ACSOs are brought into play, or the product serves as an intermediate such as an active ingredient-diallyl thiosulfinate for synthesizing allium.
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Paragraph 0065; 0066
(2017/05/26)
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- Efficient S-alkylation of cysteine in the presence of 1,1,3,3- tetramethylguanidine
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The synthesis of S-alkylated cysteine derivatives was carried out successfully in the presence of 1,1,3,3-tetramethylguanidine. Alkylation proceeded in high yields on unprotected amino acids and peptides containing a sulfhydryl group.
- W?ostowski, Marek,Czarnocka, Sylwia,MacIejewski, Piotr
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experimental part
p. 5977 - 5979
(2010/11/21)
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- Method Of Synthesizing S-Allyl-Cysteine Analogues And Their Therapeutic Application In Treating Myocardial Infarction
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A pharmaceutical composition and methods of producing and application of the composition for treating myocardial infarction of a subject are disclosed. The pharmaceutical composition comprises a therapeutically effective amount of at least one synthesized compound selected from the group consisting of SEC, SPC, SBC, SPEC, SAC, SAMC, and SPRC, and a pharmaceutically acceptable carrier.
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Page/Page column 9; 10
(2009/04/24)
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- Cysteine based novel noncompetitive inhibitors of urease(s)-Distinctive inhibition susceptibility of microbial and plant ureases
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Based on the catalysis mechanism of urease, a homologous series of 10 cysteine derivatives (CysDs) was designed and synthesized, and their inhibitory activities were evaluated for microbial ureases (Bacillus pasteurii, BPU, and Proteus mirabilis, PMU) and for a plant urease [jack bean (Cavavalia ensiformis), JBU]. As already described, thiol-compounds might inhibit urease activity by chelating the nickel atoms involved in the catalysis process. In contrast to cysteine, which has been reported to be a very weak urease inhibitor, we verified a potential inhibitory activity of these CysDs. The kinetic data demonstrate that thiol derivatives are more effective than the respective thioether derivatives. Besides, thiol-CysDs had a reduced activity in acidic pH (5.0). Lineweaver-Burk plots indicated that the nature of inhibition was of noncompetitive type for all 10 compounds, with the minimum Ki value of 2 μM for N,N-dimethyl l-cysteine. It is proposed that these classes of compounds are more potent inhibitors of the bacterial ureases, compared with the plant-originated urease. Since microbial urease is directly involved in the infection process of many pathological organisms, this work demonstrates that thiol-CysDs represent a class of new potential urease inhibitors.
- Amtul, Zareen,Kausar, Naheed,Follmer, Cristian,Rozmahel, Richard F.,Atta-Ur-Rahman,Kazmi, Syed Arif,Shekhani, Mohammed Saleh,Eriksen, Jason L.,Khan, Khalid M.,Choudhary, Mohammad Iqbal
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p. 6737 - 6744
(2007/10/03)
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- Acylase I-catalyzed deacetylation of N-acetyl-L-cysteine and S-alkyl-N- acetyl-L-cysteines
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The aminoacylase that catalyzes the hydrolysis of N-acetyl-L-cysteine (NAC) was identified as acylase I after purification by column chromatography and electrophoretic analysis. Rat kidney cytosol was fractionated by ammonium sulfate precipitation, and the proteins were separated by ion-exchange column chromatography, gel-filtration column chromatography, and hydrophobic interaction column chromatography. Acylase activity with NAC and N-acetyl-L- methionine (NAM), a known substrate for acylase I, as substrates coeluted during all chromatographic steps. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the protein was purified to near homogeneity and had a subunit M(r) of 43 000, which is identical with the M(r) of acylase I from porcine kidney and bovine liver. n-Butylmalonic acid was a slow-binding inhibitor of acylase I and inhibited the deacetylation of NAC with a K(i) of 192 ± 27 μM. These results show that acylase I catalyzes the deacetylation of NAC. The acylase I-catalyzed deacetylation of a range of S-alkyl-N- acetyl-L-cysteines, their carbon and oxygen analogues, and the selenium analogue of NAM was also studied with porcine kidney acylase I. The specific activity of the acylase I-catalyzed deacetylation of these substrates was related to their calculated molar volumes and log P values. The S-alkyl-N- acetyl-L-cysteines with short (C0-C3) and unbranched S-alkyl substituents were good acylase I substrates, whereas the S-alkyl-N-acetyl-L-cysteines with long (>C3) and branched S-alkyl substituents were poor acylase I substrates. The carbon and oxygen analogues of S-methyl-N-acetyl-L-cysteine and the carbon analogue of S-ethyl-N-acetyl-L-cysteine were poor acylase I substrates, whereas the selenium analogue of NAM was a good acylase I substrate.
- Uttamsing, Vinita,Keller,Anders
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p. 800 - 809
(2007/10/03)
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- Enzymatic Synthesis of S-Substituted L-Cysteines with Tryptophan Synthase of Escherichia coli
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The α2β2 comlex of tryptophan syntase from Escherichia coli catalyzes β-replacement reactions of L-serine and its derivatives (e.g., β-chloro-L-alanine and O-methyl-DL-serine) with various alkanethiols.The products from thiobenzyl alcohol and ethanethiol were isolated to demonstrate the enzymatic synthesis of the corresponding S-substituted L-cysteines.Reactivities of various S-substituent donors were examined, and thiols such as thiobenzyl alcohol, 1-propanethiol and 1-butanethiol were found to be much more efficient substituent donors than the physiological substrate, indole.In addition, tryptophan synthase catalyzes β-replacement reactions of L-threonine with thiols to form the corresponding S-substituted β-methylcysteines, which are also produced by β-addition reactions of L-vinylglycine with thiols.These enzymatic reactions facilitate the synthesis of various sulfur-containing amino acids.
- Esaki, Nobuyoshi,Tanaka, Hidehiko,Miles, Edith Wilson,Soda, Kenji
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p. 2861 - 2864
(2007/10/02)
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- Synthesis of L-Cysteine and Its Analogues by Intact Cells Containing Cysteine Desulfhydrase
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Cysteine desulfhydrase catalyzes β-replacement, the reverse reaction of α,β-elimination, as well as α,β-elimination.These reactions were studied with intact cells of Aerobacter aerogenes I-3-2 and Aerobacter cloacae IFO 12009 containing cysteine desulfhydrase.L-Cysteine and its analogues were synthesized by replacement and reverse reactions using intact cells. β-Chloro-L-alanine, L-cysteine, S-methyl-L-cysteine, S-allyl-L-cysteine and L-serine were used as substrates together with hydrogen sulfide and methyl mercaptan to synthesize L-cysteine and S-methyl-L-cysteine via replacement reaction by intact cells.L-Cysteine synthesized from β-chloro-L-alanine was confirmed to be entirely in L-form after isolation and identification of the product.The reverse reaction for synthesis of L-cysteine and S-methyl-L-cysteine from hydrogen sulfide or methyl mercaptan, pyruvate and ammonia was also catalyzed by intact cells. β-Chloro-L-alanine was found to be the best substrate for synthesis of L-cysteine and S-methyl-L-cysteine by β-replacement reaction.
- Ohkishi, Haruyuki,Nishikawa, Daikichiro,Kumagai, Hidehiko,Yamada, Hideaki
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p. 259 - 264
(2007/10/02)
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