- Artificial [FeFe]-hydrogenase: On resin modification of an amino acid to anchor a hexacarbonyldiiron cluster in a peptide framework
-
A general method for immobilization of synthetic analogues of the [FeFe]-hydrogenase in designed peptides via on resin modification of an amino acid side chain with a dithiol functional group is described. Utilizing a unique amine side chain as anchor, the dithiol unit is coupled to the peptide via formation of an amide. This dithiol unit precisely positions the two required sulfur atoms for the formation of a [(μ-SRS){Fe-(CO)3} 2] cluster on reaction with [Fe3(CO)12]. UV/Vis and FTIR spectroscopy demonstrate formation of the desired complex.
- Roy, Souvik,Shinde, Sandip,Hamilton, G. Alexander,Hartnett, Hilairy E.,Jones, Anne K.
-
-
Read Online
- Properties of dihydroasparagusic acid and its use as an antidote against mercury(II) poisoning
-
Dihydroasparagusic acid is the first naturally occurring dimercaptanic compound that was isolated in 1948 from Asparagus concentrate. Although several synthetic procedures were proposed in the past decades for this natural substance, most of its chemical properties remain unstudied. In this work the capacity of the acid to act as an antidote against mercury(II) toxicity was evaluated in a simple biological model system, Saccharomyces cerevisiae, and is explained by the formation of a precipitate between mercury(II) and dihydroasparagusic acid. The precipitate was analyzed and studied. The solubility was determined by measuring in equilibrated solutions either the concentration of the total mercury(II) present in solution or the free concentration of hydrogen ions. The protonation constants were determined at 25 C and in 1.00 M NaCl, as constant ionic medium, by means of potential difference measurements of a galvanic cell with a glass electrode. The experimental data are explained by proposing the chemical composition of the precipitate and the value of its solubility product. As the solubility of the precipitate increases by increasing the concentration of dihydroasparagusic acid, the further formation of a complex between mercury(II) and dihydroasparagusic acid is assumed. Graphical abstract: [Figure not available: see fulltext.]
- Bianco, Armandodoriano,Bottari, Emilio,Festa, Maria Rosa,Gentile, Lorella,Serrilli, Anna Maria,Venditti, Alessandro
-
-
Read Online
- Dihydroasparagusic acid: Antioxidant and tyrosinase inhibitory activities and improved synthesis
-
Dihydroasparagusic acid (DHAA) is the reduced form of asparagusic acid, a sulfur-containing flavor component produced by Asparagus plants. In this work, DHAA was synthetically produced by modifying some published protocols, and the synthesized molecule was tested in several in vitro assays (DPPH, ABTS, FRAP-ferrozine, BCB, deoxyribose assays) to evaluate its radical scavenging activity. Results show that DHAA is endowed with a significant in vitro antioxidant activity, comparable to that of Trolox. DHAA was also evaluated for its inhibitory activity toward tyrosinase, an enzyme involved, among others, in melanogenesis and in browning processes of plant-derived foods. DHAA was shown to exert an inhibitory effect on tyrosinase activity, and the inhibitor kinetics, analyzed by a Lineweaver-Burk plot, exhibited a competitive mechanism. Taken together, these results suggest that DHAA may be considered as a potentially active molecule for use in various fields of application, such as pharmaceutical, cosmetics, agronomic and food.
- Venditti, Alessandro,Mandrone, Manuela,Serrilli, Anna Maria,Bianco, Armandodoriano,Iannello, Carmelina,Poli, Ferruccio,Antognoni, Fabiana
-
-
Read Online
- Synthesis of Asparagusic Acid Modified Lysine and its Application in Solid-Phase Synthesis of Peptides with Enhanced Cellular Uptake
-
Cyclic disulfides, such as asparagusic acid, enhance the uptake of a variety of cargoes into live cells. Here, we report a robust and scalable synthesis of an asparagusic acid modified lysine. This amino acid can be used in solid-phase peptide synthesis. We confirmed that incorporation of this building block into the sequence of a peptide increases its cellular uptake substantially.
- Tirla, Alina,Hansen, Moritz,Rivera-Fuentes, Pablo
-
supporting information
p. 1289 - 1292
(2018/06/13)
-
- 1,2-DITHIOLANE AND DITHIOL COMPOUNDS USEFUL IN TREATING MUTANT EGFR-MEDIATED DISEASES AND CONDITIONS
-
Compositions of the invention comprise 1,2-dithiolane, dithiol and related compounds useful as therapeutic agents for the treatment and prevention of diseases and conditions associated with aberrant EGFR activity.
- -
-
Paragraph 0313-0314
(2018/08/12)
-
- 1,2-DITHIOLANE AND DITHIOL COMPOUNDS USEFUL IN TREATING MUTANT EGFR-MEDIATED DISEASES AND CONDITIONS
-
Compositions of the invention comprise 1,2-dithiolane, dithiol and related compounds useful as therapeutic agents for the treatment and prevention of diseases and conditions associated with aberrant EGFR activity.
- -
-
Paragraph 0250; 0251
(2018/08/09)
-
- Fluorinating cleavage of solid phase linkers for combinatorial synthesis
-
(Figure Presented) Multitasking: A new preparative route to fluorine-containing compounds combines the advantages ofsolid-phase synthesis with the incorporation off luorine at the end ofthe synthetic route. A sulfur linker enables simultaneous fluorination of the target structures in the cleavage step. As it is stable under different reaction conditions, the linker has potential in the combinatorial synthesis off luorinated drug structures.
- Wiehn, Matthias S.,Lindell, Stephen D.,Braese, Stefan
-
supporting information; experimental part
p. 8120 - 8122
(2009/04/13)
-
- Composition to permanently reshape the hair containing at least one carboxydithiol
-
The present invention relates to an aqueous reducing composition, for the first step of a process to permanently reshape the hair, comprising, in a cosmetically acceptable medium, one or more carboxydithiols as reducing agents.
- -
-
Page/Page column 10-11
(2008/06/13)
-
- Comparisons of rate constants for thiolate-disulfide interchange in water and in polar aprotic solvents using dynamic 1H NMR line shape analysis
-
The rate constants for representative thiolate-disulfide interchange reactions are larger in DMSO and DMF than in water by a factor of approximately 2300 at 24 °C. The log of the rate constant is directly proportional to the mole fraction of D2O in mixtures of DMSO and D2O, even at small mole fractions of D2O. This linear proportionality suggests that thiolate anion is not specifically solvated by water and that hydrogen bonding is relatively unimportant in stabilizing this species. The values of ΔS# for thiolate-disulfide interchange are approximately -10 cal/(deg mol), presumptively because of loss in the entropy of the reactants in going from ground to transition state, partially compensated by a gain in entropy from solvent release. Introduction of a hydroxyl group β to the C-S bond slows the reaction by a factor of 2-15; the introduction of methyl groups β to the C-S bond slows the rate by factors of 3-20. A number of substances have been screened as potential catalysts for thiolate-disulfide interchange in water: none showed useful levels of catalytic activity, although phenylselenol did accelerate the interchange significantly.
- Singh, Rajeeva,Whitesides, George M.
-
p. 1190 - 1197
(2007/10/02)
-
- ORALLY EFFECTIVE ANTI-HYPERTENSIVE AGENTS
-
Novel thiolester compounds are disclosed which are orally effective angiotensin converting enzyme inhibitors useful in the treatment of mammalian hypertension. They have the formula, EQU1 wherein Z denotes-B-A 2, R 1 is H or an acyl group, A 1 is a carboxylic acid containing at least one amino or imino-N-, A 2 is a carboxylic acid containing at least one amino or imino-N-or a lower alkyl ester or amide thereof, B is a 2-4 carbon backbone chain in mercapto linkage to S which includes a carbonyl or sulfonyl group joined in carboxamido or sulfonamido linkage, respectively, to A 2. Preferably A 2 includes a 4-6 membered C-N ring or a 5 membered ring of one N, one S and 3 C atoms.
- -
-
-
- Anti-hypertensive agents
-
Novel inhibitors of angiotensin converting enzyme having the general formula R--A--S--Z are disclosed as potent inhibitors of angiotensin converting enzyme and are useful anti-hypertensive agents.
- -
-
-
- PYRROLIDINE AND PIPERIDINE-2-CARBOXYLIC ACID DERIVATIVES
-
New substituted acyl derivatives of amino acids which have the general formula STR1 are useful as angiotensin converting enzyme inhibitors.
- -
-
-