cas 18598-63-5, L-Cysteine methyl ester hydrochloride

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Chiral molecular recognition in monolayers of diastereomeric N-acylamino acid methyl esters at the air/water interface
This article continues our study of the effects of headgroup geometry and temperature on chiral recognition in the force-area isotherms, thermodynamics of spreading, and surface shear viscosities of monolayers and mixed monolayers of long-chain amino acid ester surfactants. N-Stearoyl - and lauroyl - derivatives of the methyl esters of cysteine, cystine, and threonine are compared to the previously-reported serine derivative. The structural points at issue are as follows: (a) the effects of replacing the hydroxyl group of serine with the thiol group of cysteine; (b) the effect of joining two cysteine groups through their sulfur atoms to produce the two-chain cystine surfactant; and (c) the effect of attaching a methyl group to the carbon bearing the hydroxyl group in stearoylserine methyl ester (SSME) to produce the bulkier stearoylthreonine methyl ester (STME). Comparison is first made for the melting point versus enantiomer composition of the crystals for each compound. In all four cases a racemate is formed. Next, the corresponding effects of enantiomeric composition versus the appropriate surface properties are presented and behavior similar to the melting point curves is seen, implying stereoselective behavior when the monolayers are in equilibrium with their crystals or quasicrystalline condensed surface phases. Diastereomeric effects were small, since meso-dilauroylcystine dimethyl ester (DLCDME) showed properties which were nearly identical to its D and L enantiomers, and the allo form of STME was similar to its enantiomers. All four compounds showed distinctly different force-area curves for their enantiomers versus their racemic mixtures, but the shapes of the curves and phase behavior (between liquid-expanded and liquid-condensed films) depended heavily on temperature. All force-area curves show hysteresis effects in the difference between the compression and expansion regions, indicating, as we have shown before, that relaxation of compressed monolayer states is slow and that the films are in metastable states. Phase behavior is an erratic function of headgroup and temperature. Also, there is no general pattern of whether racemates or enantiomers are most expanded. No crystals of quality sufficient for X-ray analysis could be grown, so rigorous interpretation of properties and behavior in terms of structure cannot be made. However, clear differences between the behavior of stearoylcysteine methyl ester (SCME) and SSME can be interpreted in terms of hydrogen bonding of the serine hydroxyl group to the water subphase. Furthermore, comparison of force-area curves for a series of diastereomeric mixtures of L-STME and L-allo-STME with D- and L-SSME suggests that the stereochemistry at the carbon between the ester and amide functions is primarily responsible for the stereoselectivity in the packing of STME films. Films of SCME were too condensed to allow a surface viscosity study, but those of DLCDME and STME exhibited Newtonian flow with essentially no stereoselectivity in their flow properties.
Heath, Jonathan G.,Arnett, Edward M.
p. 4500 - 4514
(1992)
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Redox-Driven Chiral Inversion of Water-Soluble Pillar[5]arene with l -Cystine Derivative in the Aqueous Medium
In the aqueous solution, l-CySS-OMe induced pS-WP5 from racemic WP5. Upon the addition of dithiothreitol as a reducing reagent to the above system, pS-WP5 was then converted to pR-WP5 for the reason that l-CySS-OMe was reduced to l-Cys-OMe. Followed by the addition of H2O2 as an oxidation reagent, pR-WP5 was converted back to pS-WP5. The chiral conformational transferring process between pR-WP5 and pS-WP5 can be easily and visually observed by reading the CD signal.
Chen, Yuan,Sun, Baobao,Wang, Ranran,Shi, Conghao,Cheng, Ming,Jiang, Juli,Lin, Chen,Wang, Leyong
p. 7423 - 7427
(2021/10/01)

Bicyclic Lactams Derived from Serine or Cysteine and 2-Methylpropanal
Bicyclic lactams may be prepared from serine or cysteine and 2-methylpropanal; the resulting S, N -heterocycles are more stable than the corresponding O, N -heterocycles but both are synthetic intermediates capable of further elaboration.
Bagum, Halima,Christensen, Kirsten E.,Genov, Miroslav,Moloney, Mark G.,Pretsch, Alexander,Pretsch, Dagmar,Shire, Bethany R.
supporting information
p. 378 - 382
(2020/02/27)

Amino acid conjugates of 2-mercaptobenzimidazole provide better anti-inflammatory pharmacology and improved toxicity profile
Benzimidazole is an important pharmacophore for clinically active drugs against inflammation and treatment of pain, however, it is associated with gastrointestinal side effects. Here we synthesized benzimidazole based agents with significant analgesic/anti-inflammatory potential but with less gastrointestinal adverse effects. In this study, we synthesized novel, orally bioavailable 2-mercaptobenzimidazole amino acid conjugates (4a–4o) and screened them for analgesic, anti-inflammatory and gastro-protective effects. The synthesized 2-mercaptbenzimidazole derivatives were characterized for their structure using FTIR, 1H NMR and 13C NMR spectroscopic techniques. The 2-mercaptobenzimidazole amino acid conjugates have found to possess potent analgesic, anti-inflammatory and gastroprotective activities, particularly with compound 4j and 4k. Most of the compounds exhibited remarkable anti-ulcer and antisecretory effects. Molecular docking studies were carried out to study the binding affinities and interactions of the synthesized compounds with target proteins COX-2 (PDB ID: 3LN1) and H+/K+-ATPase (PDB ID: 5Y0B). Our results support the clinical promise of these newly synthesized 2-mercaptobezimidazol conjugates as a component of therapeutic strategies for inflammation and analgesia, for which the gastric side effects are always a major limitation.
Khan, Muhammad T.,Nadeem, Humaira,Khan, Arif-ullah,Abbas, Muzaffar,Arif, Muazzam,Malik, Nadia Shamshad,Malik, Zulkifal,Javed, Ibrahim
p. 1057 - 1072
(2020/08/13)

Hydroxyphosphinylacetic acid as a chiral auxiliary compound
The aim of the presented research was to check whether 2-hydroxy-2-(ethoxyphenylphosphinyl)acetic acid is a versatile chiral phosphonic auxiliary (readily seen in 31P NMR). The preliminary studies indicate that this compound may be used as chiral derivatizing agents for amines and alcohols, since the separation of selected examples of diastereomeric alcohols and amines in 31P NMR spectra was found to be satisfactory. The preliminary research about using this compound as a CSA are also promising.
Majewska, Paulina
p. 585 - 590
(2019/01/04)

Synthetic Access to 3-Substituted Pyroglutamic Acids from Tetramate Derivatives of Serine, Threonine, allo-Threonine, and Cysteine
A general route which provides direct access to pyroglutamates from tetramates, making use of Suzuki coupling on an enol mesylate, followed by reduction, is reported. This work permits direct scaffold hopping from tetramate to substituted pyroglutamates. Some compounds in the library showed modest antibacterial activity against Gram-positive bacteria.
Bagum, Halima,Christensen, Kirsten E.,Genov, Miroslav,Pretsch, Alexander,Pretsch, Dagmar,Moloney, Mark G.
p. 10257 - 10279
(2019/08/20)

Synthetic access to 3,4-disubstituted pyroglutamates from tetramate derivatives from serine, allo-threonine and cysteine
A route allowing the conversion of substituted tetramates to 3,4-disubstituted pyroglutamates, making use of Suzuki coupling on an enol mesylate, followed by reduction, is both general and fully stereoselective.
Bagum, Halima,Christensen, Kirsten E.,Genov, Miroslav,Pretsch, Alexander,Pretsch, Dagmar,Moloney, Mark G.
(2019/09/07)

Selective Photoredox Trifluoromethylation of Tryptophan-Containing Peptides
For application in drug discovery and biomedicine, it is crucial to develop new biocompatible methods to modify polypeptides. Herein, a visible-light-induced photoredox trifluoromethylation of tryptophan-containing peptides is reported. Under a mild, biocompatible, and straightforward condition, this strategy could incorporate the trifluoromethyl group into tryptophan residue with excellent chemo- and site-selectivity. The use of lower photocatalyst loading in 2 mol-% and cheap CF3SO2Na salt represents a great catalytic activity and economic CF3 source. This direct trifluoromethylation strategy allows the ready study of fluorinated peptides exploiting 19F-NMR. Additionally, the development of this protocol enables the study of biochemical systems and potentially modulates the function of biomolecules. Careful mechanistic studies (Stern-Volmer fluorescence quenching, EPR, and radical inhibition/trapping experiments) indicate that the reaction would proceed with a radical–radical cross-coupling procedure.
Ding, Bo,Weng, Yue,Liu, Yunqing,Song, Chunlan,Yin, Le,Yuan, Jiafan,Ren, Yanrui,Lei, Aiwen,Chiang, Chien-Wei
p. 7596 - 7605
(2019/12/15)

Purple acid phosphatase inhibitors as leads for osteoporosis chemotherapeutics
Purple acid phosphatases (PAPs) are metalloenzymes that catalyse the hydrolysis of phosphate esters under acidic conditions. Their active site contains a Fe(III)Fe(II) metal centre in mammals and a Fe(III)Zn(II) or Fe(III)Mn(II) metal centre in plants. In humans, elevated PAP levels in serum strongly correlate with the progression of osteoporosis and metabolic bone malignancies, which make PAP a target suitable for the development of chemotherapeutics to combat bone ailments. Due to difficulties in obtaining the human enzyme, the corresponding enzymes from red kidney bean and pig have been used previously to develop specific PAP inhibitors. Here, existing lead compounds were further elaborated to create a series of inhibitors with Ki values as low as ～30 μM. The inhibition constants of these compounds were of comparable magnitude for pig and red kidney bean PAPs, indicating that relevant binding interactions are conserved. The crystal structure of red kidney bean PAP in complex with the most potent inhibitor in this series, compound 4f, was solved to 2.40 ? resolution. This inhibitor coordinates directly to the binuclear metal centre in the active site as expected based on its competitive mode of inhibition. Docking simulations predict that this compound binds to human PAP in a similar mode. This study presents the first example of a PAP structure in complex with an inhibitor that is of relevance to the development of anti-osteoporotic chemotherapeutics.
Hussein, Waleed M.,Feder, Daniel,Schenk, Gerhard,Guddat, Luke W.,McGeary, Ross P.
p. 462 - 479
(2018/08/21)

A pyrroline ketone sulfur derivative and its preparation method and application
The invention belongs to the field of pesticide and plant protection and discloses pyrrolidone sulfur derivatives or their physiologically soluble salts. The pyrrolidone sulfur derivatives have a structural formula (I), wherein R=-(CH)nSCmHm, n is an integer of 1-7, m is an integer of 0-5, the case of n=2 and m=1 is excluded and the case of n=2 and m=2 is excluded. The invention also discloses a preparation method of the pyrrolidone sulfur derivatives or a use of the pyrrolidone sulfur derivatives in prevention and control of weeds. Compared with the original compound, the pyrrolidone sulfur derivatives or their physiologically soluble salts have higher weeding activity and a lower synthesis cost and can be stored easily. After contacting with the pyrrolidone sulfur derivative liquid, weeds produce cell death and brown disease spots at the contacting positions. The pyrrolidone sulfur derivative liquid can kill weeds usually in 3-5 days, has weeding broad spectrum activity, has small environmental pollution and less residue, has little activity after entering into solid in use, can be passivated fast and has very high environment safety.
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Paragraph 0038; 0042

(2018/11/27)

Benzoxaborole Antimalarial Agents. Part 5. Lead Optimization of Novel Amide Pyrazinyloxy Benzoxaboroles and Identification of a Preclinical Candidate
Carboxamide pyrazinyloxy benzoxaboroles were investigated with the goal to identify a molecule with satisfactory antimalarial activity, physicochemical properties, pharmacokinetic profile, in vivo efficacy, and safety profile. This optimization effort discovered 46, which met our target candidate profile. Compound 46 had excellent activity against cultured Plasmodium falciparum, and in vivo against P. falciparum and P. berghei in infected mice. It exhibited good PK properties in mice, rats, and dogs. It was highly active against the other 11 P. falciparum strains, which are mostly resistant to chloroquine and pyrimethamine. The rapid parasite in vitro reduction and in vivo parasite clearance profile of 46 were similar to those of artemisinin and chloroquine, two rapid-acting antimalarials. It was nongenotoxic in an Ames assay, an in vitro micronucleus assay, and an in vivo rat micronucleus assay when dosed orally up to 2000 mg/kg. The combined properties of this novel benzoxaborole support its progression to preclinical development.
Zhang, Yong-Kang,Plattner, Jacob J.,Easom, Eric E.,Jacobs, Robert T.,Guo, Denghui,Freund, Yvonne R.,Berry, Pamela,Ciaravino, Vic,Erve, John C. L.,Rosenthal, Philip J.,Campo, Brice,Gamo, Francisco-Javier,Sanz, Laura M.,Cao, Jianxin
p. 5889 - 5908
(2017/07/22)

Highly efficient synthetic method on pyroacm resin using the boc SPPS protocol for C-terminal cysteine peptide synthesis
A very effective process on Pyroacm resin was developed for solid-phase peptide synthesis (SPPS) of C-terminal cysteine and cysteine ester peptides. The process uses cysteine side chain anchoring to the Pyroacm resin and the Boc protocol for SPPS. The Pyroacm resin showed remarkable stability under standard trifluoromethanesulfonic acid (TFMSA) cleavage condition. TFMSA cleavage of protecting groups generates a peptide-linked resin, which can be subjected to peptide modification reactions. Finally, the peptide can be cleaved from the resin using methoxycarbonylsulfenyl chloride. The utility of this protocol was demonstrated by its applications to the synthesis of model peptides, key intermediates in the preparation of natural products riparin 1.2 and a-factor.
Juvekar, Vinayak,Kim, Kang-Tae,Gong, Young-Dae
p. 54 - 62
(2017/01/16)

A [...] analogs, its preparation process and its application
The invention discloses a largazole analogue which contains alkyl disulfide side chains and is represented by formula I, and a preparation method and applications thereof. The largazole analogue possesses relatively high antineoplastic activity and selectivity, can be used for development of antitumor drugs. Raw materials of the largazole analogue are cheap and easily available; and the preparation method is simple, and is a method suitable for industrialization. R in formula represents an alkyl group containing 1 to 8 carbon atoms.
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Paragraph 0102-0104

(2016/10/08)

Synthesis and antibacterial activities of Yanglingmycin analogues
The synthesis of Yanglingmycin and its enantiomer, along with eighteen Yanglingmycin analogues is reported. The structures were confirmed mainly by analyses of NMR spectral data. Antibacterial activity assays showed that Yanglingmycin and some of its analogues exhibited significant antibacterial activities against two important agricultural pathogenic bacteria, Ralstonia solanacearum and Pseudomonas syringae pv. actinidiae, with minimum inhibitory concentration (MIC) values ranging from 3.91 to 15.62 μg/mL. The antibacterial activities exhibited by Yanglingmycin and its analogues are promising, suggesting potential in the development of compounds for novel bactericides.
Li, Long-Bo,Dan, Wen-Jia,Tan, Fang-Fang,Cui, Li-Hui,Yuan, Zhi-Peng,Wu, Wen-Jun,Zhang, Ji-Wen
p. 33 - 37
(2015/01/30)

Syntheses and evaluation of drug-like properties of CO-releasing molecules containing ruthenium and group 6 metal
In this paper, drug-like properties of two series of carbonyl metal CO-releasing molecules, Ru(CO)3ClnL (n = 1, L = amino acid or its derivatives 1-7, L = acetylacetone 8 or 2,2′-bipyridyl 9; n = 2, L = aminopyridine derivatives 10-13; n = 0, L = salicylaldehyde Schiff base 14-15) and M(CO)5L(M = Cr, Mo, W; L = glycine methyl ester 16-18; L = N-methyl imidazole 19-21), were preliminarily evaluated from four aspects involving in cytotoxicity, in vivo toxicity, bio-distribution and metabolism. Cytotoxic effects of all complexes were assayed by MTT. IC50 values of complexes 1-15 were 39.55-240.16 mg/l, and those of complexes 16 and 18 were 21.36-22.21 mg/l. Toxicity tests of mice used oral acute toxic class method and got LD50 values of some complexes; among them, LD50 of complex 1 was in 800-1000 mg/kg, complex 7 in 1100-1500 mg/kg and complex 18 in 75-125 mg/kg. After several consecutive administrations, tested complexes severely damaged liver and kidney in both functional and morphological aspects. And by metal ions measurements using ICP-AES, we found that the tested complexes were unevenly distributed in tissues and organs. In vivo, RuII in complexes was oxidized to RuIII by P450 enzymes, and for Mo 0 and W0 in complexes, part of them transformed into higher oxidation state, the others kept original state.
Wang, Pengpeng,Liu, Huapeng,Zhao, Quanyi,Chen, Yonglin,Liu, Bin,Zhang, Baoping,Zheng, Qian
p. 199 - 215
(2014/02/14)

Cycloforskamide, a cytotoxic macrocyclic peptide from the sea slug Pleurobranchus forskalii
A macrocylic dodecapeptide, cycloforskamide, was isolated from the sea slug Pleurobranchus forskalii, collected off Ishigaki Island, Japan. Its planar structure was deduced by extensive NMR analyses and was further confirmed by MS/MS fragmentation analyses. Finally, the absolute configuration was determined by total hydrolysis and chiral-phase gas chromatographic analysis. This novel dodecapeptide contains three d-amino acids and three thiazoline heterocycles and exhibits cytotoxicity against murine leukemia P388 cells, with an IC 50 of 5.8 μM.
Tan, Karen Co,Wakimoto, Toshiyuki,Takada, Kentaro,Ohtsuki, Takashi,Uchiyama, Nahoko,Goda, Yukihiro,Abe, Ikuro
p. 1388 - 1391
(2013/08/23)

NUCLEOSIDE DERIVATIVES, SYNTHESIS METHODS AND USES THEREOF FOR PREPARING ANTI-TUMOR AND ANTI-VIRUS MEDICAMENTS
The present invention relates to the field of pharmacochemistry. Disclosed are fluorinated and azido-substituted pyrimidine nucleoside derivatives, and preparation methods and uses thereof. The structural formula is as shown (I). These compounds can be used for preparing medicaments for treating diseases such as tumors and viral infections, and can be used separately or in combination with other medicaments. The compounds also have effective activity against diseases such as tumors and viral infections, while having few side effects, and thus have potential application value.
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Paragraph 0062

(2013/07/25)

PYRIMIDINE NUCLEOSIDE DERIVATIVES, SYNTHESIS METHODS AND USES THEREOF FOR PREPARING ANTI-TUMOR AND ANTI-VIRUS MEDICAMENTS
The present invention relates to the field of pharmacochemistry. Disclosed are fluorinated and azido-substituted pyrimidine nucleoside derivatives, and preparation methods and uses thereof. The structural formula is as shown (I). These compounds can be used for preparing medicaments for treating diseases such as tumors and viral infections, and can be used separately or in combination with other medicaments. The compounds also have effective activity against diseases such as tumors and viral infections, while having few side effects, and thus have potential application value.
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Paragraph 0068

(2013/11/19)

Native chemical ligation, thiol-ene click: A methodology for the synthesis of functionalized peptides
The sequential combination of native chemical ligation and thiol-ene radical chemistry (NCL-TEC) on the resulting cysteine thiol has been investigated as a methodology for rapidly accessing functionalized peptides. Three sequential cycles of native chemical ligation and subsequent thiyl radical reactions (including a free-radical-mediated desulfurization reaction) were carried out on a peptide backbone demonstrating the iterative nature of this process. The versatility of the thiyl radical reaction at cysteine was demonstrated through the introduction of a number of different side chains including an amino acid derivative, a carbohydrate group, and an alkyl azide. Conditions were developed that allowed the sequential NCL-TEC process to proceed in high yield.
Markey, Lyn,Giordani, Silvia,Scanlan, Eoin M.
p. 4270 - 4277
(2013/06/27)

The synthesis and biological evaluation of novel Danshensu-cysteine analog conjugates as cardiovascular-protective agents
A series of novel amide and thioester conjugates between Danshensu and cysteine derivatives have been designed and synthesized based on the strategy of "medicinal chemical hybridization". Pharmacological evaluation indicated that the amide conjugates 3a/4a/17a and thioester conjugates 6a-d exhibited obvious protective effects on H2O2-induced human umbilical vein endothelial cells (HUVECs). Pretreated with these conjugates could increase glutathione (GSH) activity and decrease malondialdehyde (MDA) level. Further study on mechanism of compound 4a revealed that it was related to its mitochondrial-protective effect and regulation of apoptosis-related proteins expression (Bax, p53, PARP, caspase-3, caspase-9 and Bcl-2). These results indicate that these Danshensu-cysteine analog conjugates possess significant cardiovascular-protective effects and merit further investigation.
Jia, Yaoling,Zhou, Pengfei,Wang, Yang,Dong, Xiaoyi,Liu, Xinhua,Pan, Lilong,Xin, Hong,Zhu, Yi Zhun
p. 176 - 187,12
(2020/07/31)

OLEFIN METATHESIS REACTIONS OF AMINO ACIDS, PEPTIDES AND PROTEINS CONTAINING ALLYL SULFIDE GROUPS
A method for the modification of an amino acid, protein or peptide is disclosed. The method comprises reacting a carbon-carbon double bond-containing compound with an amino acid, a protein or a peptide containing an allyl sulfide group in the presence of a catalyst which promotes olefin metathesis, to form a modified amino acid, protein or peptide. Preferred carbon-carbon double bond-containing compounds include carbohydrates.
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Page/Page column 5

(2012/07/27)

Synthesis, characterization and pharmacological evaluation of amino acid conjugates of ketoprofen
Ketoprofen is used for its antipyretic, analgesic and antiinflammatory properties by inhibiting cyclooxygenase-1 and cyclooxygenase-2 enzymes reversibly, which decreases production of proinflammatory prostaglandin precursors. Ketoprofen suffers from the general side effects of nonsteroidal antiinflammatory drugs, owing to presence of free carboxylic acid group. The study aimed to retard the adverse effects of gastrointestinal origin. Different conjugates of ketoprofen have been synthesized by amidation with methyl esters of amino acids namely, phenylalanine, lysine, arginine, glycine, cysteine, valine, glutamine, serine, proline and alanine. Synthesized conjugates were characterized and evaluated for analgesic and antiinflammatory activities.
Dubey,Jain,Bhadoria,Sinha
experimental part
p. 1170 - 1174
(2012/08/28)

Synthesis, characterization and biological evaluation of amino acid conjugates of mefenamic acid
Mefenamic acid is used for its antipyretic, analgesic, antiinflammatory properties and also inhibits cyclooxygenase-1 and cyclooxygenase- 2 (COX-1 and COX-2) enzymes reversibly, which decreases production of pro-inflammatory prostaglandin precursors. Mefenamic acid suffers from the general side effects of non-steroidal antiinflammatory drugs, owing to presence of free carboxylic acid group. The study aimed to retard the adverse effects of gastrointestinal origin. Amino acid conjugates of mefenamic acid were synthesized by amidation with methyl esters of amino acids namely, phenylalanine, cysteine, glycine, lysine, arginine, valine, proline, serine, alanine and methionine. Synthesized conjugates were characterized by melting point, TLC, 1H NMR and mass spectroscopy. Synthesized conjugates were also evaluated for their analgesic and antiinflammatory activities. Comparable analgesic and anti-inflammatory activities were obtained as compared to mefenamic acid.
Dubey, Nitin,Jain, Dinesh K.,Bhadoriya, Upendra S.,Solanki, Balvant
experimental part
p. 1237 - 1241
(2012/09/07)

Olefin cross-metathesis on proteins: Investigation of allylic chalcogen effects and guiding principles in metathesis partner selection
Olefin metathesis has recently emerged as a viable reaction for chemical protein modification. The scope and limitations of olefin metathesis in bioconjugation, however, remain unclear. Herein we report an assessment of various factors that contribute to productive cross-metathesis on protein substrates. Sterics, substrate scope, and linker selection are all considered. It was discovered during this investigation that allyl chalcogenides generally enhance the rate of alkene metathesis reactions. Allyl selenides were found to be exceptionally reactive olefin metathesis substrates, enabling a broad range of protein modifications not previously possible. The principles considered in this report are important not only for expanding the repertoire of bioconjugation but also for the application of olefin metathesis in general synthetic endeavors.
Lin, Yuya A.,Chalker, Justin M.,Davis, Benjamin G.
supporting information; experimental part
p. 16805 - 16811
(2011/02/17)

A convenient catalyst for aqueous and protein Suzuki-Miyaura cross-coupling
(Figure Presented) A phosphine-free palladium catalyst for aqueous Suzuki-Miyaura cross-coupling is presented. The catalyst is active enough to mediate hindered, ortho-substituted biaryl couplings but mild enough for use on peptides and proteins. The Suzuki-Miyaura couplings on protein substrates are the first to proceed in useful conversions. Notably, hydrophobic aryl and vinyl groups can be transferred to the protein surface without the aid of organic solvent since the aryl- and vinylboronic acids used in the coupling are water-soluble as borate salts. The convenience and activity of this catalyst prompts use in both general synthesis and bioconjugation.
Chalker, Justin M.,Wood, Charlotte S. C.,Davis, Benjamin G.
supporting information; experimental part
p. 16346 - 16347
(2010/01/29)

A convenient synthesis of amino acid methyl esters
A series of amino acid methyl ester hydrochlorides were prepared in good to excellent yields by the room temperature reaction of amino acids with methanol in the presence of trimethylchlorosilane. This method is not only compatible with natural amino acids, but also with other aromatic and aliphatic amino acids.
Li, Jiabo,Sha, Yaowu
p. 1111 - 1119
(2008/09/21)

Facile conversion of cysteine and alkyl cysteines to dehydroalanine on protein surfaces: Versatile and switchable access to functionalized proteins
An efficient and robust oxidative elimination of cysteine to dehydroalanine has been discovered. The reaction is induced by O-mesitylenesulfonylhydroxylamine (MSH) and is compatible with methionine. The key elimination has been executed on protein surfaces and allows ready access to different post-translationally modified proteins through conjugate addition of sulfur nucleophiles to dehydroalanine. Treatment of the resulting thioether with MSH results in regeneration of dehydroalanine, allowing a "functional switch" by subsequent addition of a different thiol. Copyright
Bernardes, Goncalo J. L.,Chalker, Justin M.,Errey, James C.,Davis, Benjamin G.
p. 5052 - 5053
(2008/10/09)

Allyl sulfides are privileged substrates in aqueous cross-metathesis: Application to site-selective protein modification
Allyl sulfides undergo efficient cross-metathesis in aqueous media with Hoveyda-Grubbs second generation catalyst 1. The high reactivity of allyl sulfides in cross-metathesis was exploited in the first examples of cross-metathesis on a protein surface. S-Allylcysteine was incorporated chemically into the protein, providing the requisite allyl sulfide handle. Preliminary efforts to genetically incorporate S-allylcysteine into proteins are also reported. Copyright
Lin, Yuya A.,Chalker, Justin M.,Floyd, Nicola,Bernardes, Goncalo J. L.,Davis, Benjamin G.
supporting information; experimental part
p. 9642 - 9643
(2009/02/04)

New terpenoids from Stachys parviflora Benth
Two new triterpenoidal saponins were isolated from the n-butanolic extract of Stachys parviflora (Lamiaceae). Their structures were elucidated on the basis of spectral data as stachyssaponin A; 3β, 15α, 19α, 21β, 22α-pentahydroxyolean-12-ene-28-oic acid 3-O-{α-L-rhamnopyranosyl-(1 → 3)-β-D-glucopyranoside)-22-O-{α-L-arabinofuranosyl-(1 → 3)-β-D-glucopyranoside) (1) and stachyssaponin B; 2β, 3β, 15α, 21β-tetrahydroxyolean-12-ene-28-oic acid 2-O-[a-L- arabinofuranoside]-3, 21-bis-O-[β-D-glucopyranoside] (2). Copyright
Ahmad, Viqar Uddin,Arshad, Saima,Bader, Sadia,Iqbal, Shazia,Khan, Afsar,Khan, Saleha Suleman,Hussain, Javid,Tareen, Rasool Bakhsh,Ahmed, Amir
experimental part
p. 986 - 989
(2009/05/30)

THIAZOLIDINONE AMIDES, THIAZOLIDINE CARBOXYLIC ACID AMIDES, METHODS OF MAKING, AND USES THEREOF
Substituted thiazolidinone carboxylic acid amides and substituted thiazolidine carboxylic acid amides according to formulae (I) and (II) are disclosed where the various substituent groups are as defined in the specification. Methods of making these compounds, pharmaceutical compositions containing the compounds, and their use, particularly for treating or preventing cancer, are also disclosed.
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(2008/06/13)

Discovery of 2-arylthiazolidine-4-carboxylic acid amides as a new class of cytotoxic agents for prostate cancer
To improve the selectivity and antiproliferative activity of previously reported serine amide phosphates (SAPs), we designed a new series of 4-thiazolidinone amides, in which the 4-thiazolidinone moiety was introduced as a phosphate mimic. However, these 4-thiazolidinone derivatives demonstrated less cytotoxicity in prostate cancer cells despite improved selectivity over RH7777 cells. To further optimize the thiazolidinone analogues in terms of cytotoxicity and selectivity, we made closely related structural modifications, which led us to the discovery of a new class of 2-arylthiazolidine-4-carboxylic acid amides. These compounds were potent cytotoxic agents with IC50 values in the low micromolar concentration range and demonstrated enhanced selectivity in receptor-negative cells compared to SAPs and 4-thiazolidinone amides.
Gududuru, Veeresa,Hurh, Eunju,Dalton, James T.,Miller, Duane D.
p. 2584 - 2588
(2007/10/03)

Aromatic heterocyclic non-covalent inhibitors of urokinase and blood vessel formation
Novel compounds having activity as non-covalent inhibitors of urokinase and having activity in reducing or inhibiting blood vessel formation are provided. These compounds have at a group having a guanidino moiety or derivative thereof. These compounds are useful in vitro for monitoring plasminogen activator levels and in vivo in treatment of conditions which are ameliorated by inhibition of or decreased activity of urokinase and in treating pathologic conditions wherein blood vessel formation is related to a pathologic condition.
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(2008/06/13)

Inhibitors of protein isoprenyl transferases
Compounds having the formula or a pharmaceutically acceptable salt thereof wherein R1 is (a) hydrogen, (b) loweralkyl, (c) alkenyl, (d) alkoxy, (e) thioalkoxy, (f) halo, (g) haloalkyl, (h) aryl-L2—, and (i) heterocyclic-L2—; R2 is selected from (a) (b) —C(O)NH—CH(R14)—C(O)OR15, (c) (d) —C(O)NH—CH(R14)—C(O)NHSO2R16 (e) —C(O)NH—CH(R14)-tetrazolyl, (f) —C(O)NH-heterocyclic, and (g) —C(O)NH—CH(R14)—C(O)NR17R18; R3 is heterocyclic, aryl, substituted or unsubstituted cycloalkyl; R4 is hydrogen, lower alkyl, haloalkyl, halogen, aryl, arylakyl, heterocyclic, or (heterocyclic)alkyl; L1 is absent or is selected from (a) —L4—N(R5)—L5—, (b) —L4—O—L5—, (c) —L4—S(O)n—L5— (d) —L4-L6—C(W)—N(R5)—L5—, (e) —L4-L6—S(O)m—N(R5)—L5—, (f) —L4—N(R5)—C(W)—L7-L5—, (g) —L4—N(R5)—S(O)p—L7—L5—, (h) optionally substituted alkylene, (i) optionally substituted alkenylene, and (j) optionally substituted alkynylene are inhibitors of protein isoprenyl transferases. Also disclosed are protein isoprenyl transferase inhibiting compositions and a method of inhibiting protein isoprenyl transferases.
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(2008/06/13)

Novel thiazolidine derivatives as chiral catalysts in the enantioselective addition of diethylzinc to aldehydes
New chiral thiazolidine derivatives were synthesized conveniently from natural L-cysteine and showed good enantioselectivity (up to 90% ee) in the addition of diethylzinc to aldehydes. The catalytic efficiency of the thiazolidine derivatives is influenced by the different structures of the thiazolidine rings and the bulkiness of R moiety in the ester groups. (C) 2000 Elsevier Science Ltd.
Meng, Qinglin,Li, Yuelan,He, Yan,Guan, Yedi
p. 4255 - 4261
(2007/10/03)

Approaches to the tetracyclic eudistomins: the synthesis of N(10)-acetyleudistomin L
The successful synthesis of the tetracyclic ring system present in eudistomins C, E, K, and L involves a convergent approach to N(10)-acetyleudistomin L from 5-bromo-N'-hydroxytryptamine and a suitably protected cysteinal derivate.Ring C in the eudistomin was constructed by a modified Pictet-Spengler reaction and the unique 1,3,7-oxathiazepine ring (ring D) by an unprecedented intramolecular sila-Pummerer reaction.An interesting diastereoselectivity is observed in the former process.The formation of an alternative seven-membered ring cyclization product under certain conditions in the sila-Pummerer reaction is also described.
Still, Ian W. J.,Strautmanis, Juris R.
p. 1408 - 1419
(2007/10/02)

A γ-LACTAM ANALOGUE OF THE PENEMS POSSESSING ANTIBACTERIAL ACTIVITY
The synthesis of a γ-lactam analogue of penems, from aspartic acid semi-aldehyde, which possessed antibacterial activity is described.
Baldwin, Jack E.,Freeman, Richard T.,Lowe, Christopher,Schofield, Christopher J.,Lee, Eun
p. 4537 - 4550
(2007/10/02)

SYNTHESIS OF N(10)-ACETYLEUDISTOMIN L
The marine indole alkaloid derivative N(10)-acetyleudistomin L has been prepared in a convergent synthesis, starting from 5-bromoindole and L-cysteine.
Still, Ian W. J.,Strautmanis, Juris R.
p. 1041 - 1044
(2007/10/02)

Process for intermediates to 1-carbapenems and 1-carbacephems
A stereoselective process for chiral intermediates to 1-carbapenum and 1-carbacephalosporins is provided comprising the use of an N-acyl-(4R)-substituted-1,3-thiazolidine-2-thione as a chiral auxiliary in boron enolate mediated aldol condensation with a protected-β-keto ester aldehyde. E.g., benzyl 3,3-(ethylenedioxy)-4-formylbutyrate is condensed with the boron enolate formed with n-butyryl (4R)-methoxycarbonyl-1,3-thiazolidine-2-thione to provide benzyl 3,3-ethylenedioxy-(5R)-hydroxy-6-[(4R)-methoxycarbonyl-1,3-thiazolidine-2-thione-3-ylcarbonyl]octanoate. Displacement of the thiazolidine-2-thione chiral auxiliary moiety with an O-alkyl, O-acyl or O-aralkyl hydroxyamine provides the corresponding chiral intermediate as the hydroxamate.
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(2008/06/13)

ARYL-VINYLSULFONE--REAGENTIEN ZUM SCHUTZ UND NACHWEIS VON THIOLFUNKTIONEN
Aryl vinyl sulfones selectively react with thiol groups to acid-stable compounds which easily are cleaved by mild bases to thiol compounds.Ester and amide groups are not attacked under these conditions.Therefore, these compounds are good protecting groups or labels in peptide chemistry.The following aryl vinyl sulfones were investigated: phenyl vinyl sulfone 1, p-carbethoxyphenyl vinyl sulfone 15 and the fluorescent 5-dimethylaminonaphthyl 1-vinyl sulfone 5 and 5-methoxynaphthyl-1 vinyl sulfone 10.The last two compounds are very useful reagents for the quantitative determination of SH-groups in polypeptides such as enzymes.
Horner, L.,Lindel, H.
p. 1 - 8
(2007/10/02)

PHOSPHORORGANISCHE VERBINDUNGEN 97. Die Diphenylphosphinyl- und die Diphenylthiophosphinylgruppe als selektive Schutzgruppe fuer die Mercaptofunktion. Nucleophile Abloesung der Thioloestergruppe aus Thiophosphin-, Thiophosphon- und Thiophosphorsaeure-S-estern durch nicht solvatisierte...
Diphenylphosphinic acid cyanide and diphenylthiophosphonic acid cyanide react selectively with the mercaptogroup even in presence of primary aminogroups.The thioloesterbond in thiophosphinic, thiophosphonic and thiophosphoric acid S-esters is cleaved under mild conditions by unsolvated fluoride ions F*3H2O (R = C4H9) and CsF> in methylene chloride, chloroform or THF. (C6H5)2P(O)CN and (C6H5)2P(S)CN are therefore protecting group reagents for mercaptans.Diphenylphosphinic acid chloride and diphenylthiophosphinic acid chloride are N-selective in competing reactions using butylamine/butylmercaptan.In contrast to the corresponding S-selective cyanides no selectivity is observed using cysteamine and cysteinmethylester.
Horner, L.,Gehring, R.,Lindel, H.
p. 349 - 356
(2007/10/02)