- Improved method for synthesis of cysteine modified hyaluronic acid for in situ hydrogel formation
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We developed a new strategy for the functionalization of hyaluronic acid by chemical modification of its C-6 hydroxyl groups through an ether bond to obtain a cysteine-hyaluronic acid conjugate. This conjugate is suitable to prepare injectable and in situ formed hydrogels cross-linked by native chemical ligation and Michael addition under mild conditions.
- Zhang, Xin,Sun, Pengcheng,Huangshan, Lingzi,Hu, Bi-Huang,Messersmith, Phillip B.
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- SOLUTION PHASE ROUTES FOR WNT HEXAPEPTIDES
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The present disclosure relates generally to the field of polypeptide synthesis, and more particularly, to the solution phase synthesis of the Wnt hexapeptide Foxy-5 and protected derivatives and peptide fragments thereof.
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Page/Page column 17; 18
(2020/12/30)
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- A highly enantio- and diastereoselective direct aldol reaction in aqueous medium catalyzed by thiazolidine-based compounds
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Taking l-aminoacids as starting materials, a new set of enantiopure thiazolidine-based organocatalysts were prepared using a simple synthetic approach and successfully applied in the asymmetric direct aldol reaction between various cyclic ketones and aldehydes in a saturated aqueous medium. The aldol adducts were obtained with excellent enantioselectivity (up to >99% ee) and diastereoselectivity (dr >20:1).
- Rambo, Raoní Scheibler,Gross Jacoby, Caroline,Da Silva, Tiago Lima,Schneider, Paulo Henrique
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p. 632 - 637
(2015/08/03)
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- Curcumin analog cytotoxicity against breast cancer cells: exploitation of a redox-dependent mechanism
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A series of novel curcumin analogs, symmetrical dienones, were previously shown to possess cytotoxic, anti-angiogenic and anti-tumor activities. Analogs 1 (EF24) and 2 (EF31) share the dienone scaffold and serve as Michael acceptors. We propose that the anti-cancer effects of 1 and 2 are mediated in part by redox-mediated induction of apoptosis. In order to support this concept, 1 and 2 were treated with l-glutathione (GSH) and cysteine-containing dipeptides under mild conditions to form colorless water-soluble adducts, which were identified by LC/MS. Comparison of the cytotoxic action of 1, 2 and the corresponding conjugates, 1-(GSH)2 and 2-(GSH)2, illustrated that the two classes of compounds exhibit essentially identical cell killing capabilities. Compared with the yellow, somewhat light sensitive and nearly water insoluble compounds 1 and 2, the glutathione conjugates represent a promising new series of stable and soluble anti-tumor pro-drugs.
- Sun, Aiming,Lu, Yang J.,Hu, Haipeng,Shoji, Mamoru,Liotta, Dennis C.,Snyder, James P.
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scheme or table
p. 6627 - 6631
(2010/06/14)
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- DENTRITIC POLYMERS, CROSSLINKED GELS, AND THEIR USES IN ORTHOPEDIC APPLICATIONS
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The present invention provides compositions, kits, and methods for repairing cartilaginous tissue. Certain methods of the invention utilize dendritic macromolecules formed by treating a dendritic compound with light or a linking compound. In certain instances, the dendritic compounds have a lysine, cysteine, isocysteine residue or other nucleophilic group attached to their peripheries. Addition of a compound containing two or more electrophilic groups, such as aldehydes, activated esters, or acrylates, to the lysine-capped, cysteine-capped, or isocysteine-capped dendrimers produces a polymeric compound that can repair a cartilage defect.
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Page/Page column 271
(2010/10/20)
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- Inhibitors of α4β1 mediated cell adhesion
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The present invention relates to compound of formula (I), that are potent inhibitors of α4β1mediated adhesion to either VCAM or CS-1 and which could be useful for the treatment of inflammatory diseases. Specifically, the molecules of the present invention can be used for treating or preventing α4β1adhesion mediated conditions in a mammal such as a human. This method may comprise administering to a mammal or a human patient an effective amount of the compound or composition as explained in the present specification.
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Page/Page column 72-73
(2010/02/05)
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- A biomimetically inspired synthesis of the dehydropiperidine domain of thiostrepton
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The key step in the dimerization of the azadiene 1 is a hetero-Diels-Alder reaction. The product 2 constitutes the dehydropiperidine core of the antibiotic thiostrepton.
- Nicolaou,Nevalainen, Marta,Safina, Brian S.,Zak, Mark,Bulat, Stephan
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p. 1941 - 1945
(2007/10/03)
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- Total synthesis of a macrocyclic antibiotic, micrococcin P
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The first total synthesis of a macrocyclic antibiotic, micrococcin P (1), was accomplished. After constructing the central 2,3,6-tristhiazolyl- substituted pyridine skeleton [Fragment A-C segment] (21) from ethyl 2-(2- bromoacetyl-6-dimethoxymethyl-3-pyridyl)thiazole-4-carboxylate (15) in 11 steps, successive fragment condensations of 21 with ethyl 2[(Z)-1-(O-t- butyldiphenylsilyl-L-threonylamino)-1-propenyl]thiazole-4-carboxylate (29) and (S)-1-(O-methoxymethyl-L-threonylamino)-2-(O-methoxymethyl)-2-propanol (25) [the protected Fragments B and D moieties, respectively] gave the protected Fragment A-B-C-D segment 34. Subsequent deprotection of all the protecting groups of 34 with trifluoroacetic acid and then cyclization by using BOP as condensing agent under high dilution conditions gave the expected micrococcin P (1). The synthetic 1 was identical with the natural 1 with respect to the chemical and physical properties.
- Okumura, Kazuo,Nakamura, Yutaka,Shin, Chung-Gi
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p. 1561 - 1569
(2007/10/03)
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- Protected Derivatives of (R)-Cysteine and (R)-Cysteinol
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The synthesis of N, O, S protected forms of (R)-cysteine and (R)-cysteinol as bicyclic derivatives is described.The reactivity and the preparation of substituted derivatives of these systems is also discussed.
- Gonzalez, Asensio,Lavilla, Rodolfo,Piniella, Juan F.,Alvarez-Larena, Angel
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p. 3015 - 3024
(2007/10/02)
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- Gas/Solid Reactions with Acetone
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Gas/solid reactions of acetone vapor with neutral organic compounds, salts, or host crystals with strict exclusion of solvents are reported.This gas/solid technique largely avoids waste formation and saves resources.Starting hydrochlorides or hydrobromides are also synthesized by gas/solid techniques.Dihydrohalides of o-phenylenediamines give 1,5-benzodiazepines 3, aromatic and aliphatic 1,2-aminothiols (o-aminothiophenol, penicillamines, cysteine) yield five-membered thiazolines and thiazolidines 7, 9, 11, 13.Virtually all carbonyl reagents of the primary amino type 14 give quantitatively the imino derivatives 15 and water.Salt formation may be helpful for increasing melting points and sometimes reactivity as in 8, 10, and 12 if surface passivation has to be overcome.In the case of solid 14 the free bases react equally well.Acetone (2) may be quantitatively removed from exhaust gases by using hydroxylaminium phosphate with formation of free acetone oxime at high flow rates.Inclusion of acetone into various hosts (17-20, but not 16) is more efficient by imbibition from the gas phase than by crystallization from acetone as the solvent.This advantage may be utilized for gas separations.Some further gases (vapors) coexist in imbibed clathrates whereas others do not.The mechanisms of the gas/solid reactions are elucidated using atomic force microscopy (AFM).Phase rebuildings involve anisotropic movements of molecules over large distances and the formation of characteristic features.In some cases surface hydrates catalyze the gas/solid reaction.Solid-state mechanisms for imbibition from the gas phase into host crystals with formation of clathrates are similar in nature to those of the covalent reactions.These results are correlated with known X-ray crystal structures where available. - Key Words: Gas/solid reactions / Imbibition / Acetone derivatives / Atomic force microscopy / Anisotropic phase rebuilding / Waste prevention
- Kaupp, Gerd,Pogodda, Uwe,Schmeyers, Jens
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p. 2249 - 2262
(2007/10/02)
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- Asymmetric Transformation of (RS)-Cysteine via Formation of (RS)-4-Thiazolidinecarboxylic Acids
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Either (R)- or (S)-cysteine ((R)- or (S)-Cys) was efficiently obtained from (RS)-Cys by the asymmetric transformation via formation of (RS)-thiazolidinecarboxylic acid ((RS)-THC) or (RS)-2,2-dimethyl-4-thiazolidinecarboxylic acid ((RS)-DMZ) and by using (2R,3R)- or (2S,3S)-tartaric acid ((R)- or (S)-TA), as a resolving agent, in acetic acid.The asymmetric transformation was carried out by combination of crystallization of less soluble salt of (S)-THC or -DMT with (R)-TA (or salt of (R)-THC or -DMT with (S)-TA) and epimerization of soluble diastereomeric salt.The (R)- and (S)-THCs from the less soluble salts gave approximately optically pure (R)- and (S)-Cys's, respectively, in 64percent yield.The asymmetric transformation via formation of (RS)-DMT was more succeefully achieved by adding 0.1 molar equivalent of salicylaldehyde; that is, hydrolysis of the obtained less soluble salt gave optically pure (R)- and (S)-Cys's, respectively, in 80percent yield based on the (RS)-Cys used as the starting material.
- Shiraiwa, Tadashi,Kataoka, Kazuo,Sakata, Shinji,Kurokawa, Hidemoto
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p. 109 - 113
(2007/10/02)
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- Racemization of Optically Active Cysteine via Formation of 2,2-Dimethyl-4-thiazolidinecarboxylic Acid
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Optically active cysteine (Cys) was racemized via formation of (RS)-2,2-dimethyl-4-thiazolidinecarboxylic acid ((RS)-DMT) by refluxing in the presence of acetone in 10-fold molar amount in acetic acid.The formed (RS)-DMT was hydrolyzed by adding water to the reaction mixture to give (RS)-Cys in 95-97percent yield.
- Shiraiwa, Tadashi,Kataoka, Kazuo,Sakata, Shinji,Kurokawa, Hidemoto
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p. 4158 - 4160
(2007/10/02)
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- Amino-acid zwitterion equilibria: vibrational and nuclear magnetic resonance studies of methyl-substituted thiazolidine-4-carboxylic acids
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Infrared and Raman spectra (4000-100 cm-1) of solid samples of six different methyl substituted thiazolidine products of D-penicillamine and L-cysteine hydrochloride have been observed and assigned, Infrared spectra in D2O solutions have been obtained for comparison in order to study the amino-acid zwitterion equilibria.Proton and 13C nmr spectra for the compounds have also been measured.
- Howard-Lock, H. E.,Lock, C. J. L.,Martins, M. L.,Smalley, P. S.,Bell, R. A.
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p. 1215 - 1219
(2007/10/02)
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