Tag: M.W=150-200

Tsai, Cheng-Che; Chuang, Wei-Tsung; Tsai, Yow-Fu; Li, Jyun-Ting; Wu, Yu-Fa; Liao, Chun-Chen published the artcile< Intra- and intermolecular hydrogen bonds enhance the fluoride-responsiveness of functionalized glycolipid-based gelators>, Application In Synthesis of 617-55-0, the main research area is glycolipid preparation supramol gel assembly hydrogen bond fluoride.

The authors propose a facile approach toward enhancing the efficiency of fluoride-responsive gels through the positioning of functionalized receptor units, allowing tunable intra- and intermol. hydrogen bonding, in the gelator mols. The authors have prepared the new glycolipid-based gelator 2 and its hydroxy and methoxy derivatives 2a and 2b, resp., to study the effects of three types modes of supramol. assembly: solely intermol. hydrogen bonding in 2, solely intramol. hydrogen bonding in 2b, and both inter- and intramol. hydrogen bonding in 2a. 1H NMR spectra confirmed the self-assembly interactions of these glycolipid-based gelators. The authors measured the min. gel concentrations and sol-gel transitions and recorded x-ray diffraction patterns and electron micrographs to characterize the gelation behavior and structural organization of each of these supramol. gels. Among these three gelators, only 2 and 2a could form organogels in the test solvents, indicating that intermol. hydrogen bonding plays a determinant role in the supramol. assemblies leading to gelation. The self-assembly of 2 resulted in a bilayer-packed lamellar structure within ribbon-like fibers, whereas that of 2a resulted in hexagonally packed cylindrical micelles within tree-like fibers. A min. amount of 0.3 equiv of F- was required for complete disruption of the gel formed from 2a, which was approx. four times lower than that required for the gel formed from 2. Thus, the incorporation of a β-hydroxy motif-the only difference in the chem. structures of 2 and 2a-led to interesting variations in the resulting gel morphologies and enhanced the gel’s fluoride-responsiveness.

Journal of Materials Chemistry B: Materials for Biology and Medicine published new progress about Gelation. 617-55-0 belongs to class esters-buliding-blocks, and the molecular formula is C6H10O5, Application In Synthesis of 617-55-0.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Liu, Yan; Haste, Nina M.; Thienphrapa, Wdee; Nizet, Victor; Hensler, Mary; Li, Rongshi published the artcile< Marinopyrrole derivatives as potential antibiotic agents against methicillin-resistant Staphylococcus aureus (I)>, Category: esters-buliding-blocks, the main research area is Staphylococcus methicillin resistance marinopyrrole A antibiotic; MRSA; SAR; antibiotics; asymmetrical marinopyrroles; marinopyrrole.

Infections caused by drug-resistant pathogens are on the rise. The ongoing spread of methicillin-resistant Staphylococcus aureus (MRSA) strains exemplifies the urgent need for new antibiotics. The marine natural product, marinopyrrole A, was previously shown to have potent antibiotic activity against Gram-pos. pathogens, including MRSA. However, its min. inhibitory concentration (MIC) against MRSA was increased by >500 fold in the presence of 20% human serum, thus greatly limiting therapeutic potential. Here we report our discovery of a novel derivative of marinopyrrole A, designated 1a, featuring a 2-4 fold improved MIC against MRSA and significantly less susceptibility to serum inhibition. Importantly, compound 1a displayed rapid and concentration-dependent killing of MRSA. Compared to the natural product counterpart, compound 1a provides an important natural product based scaffold for further Structure Activity Relationship (SAR) and optimization.

Marine Drugs published new progress about Antimicrobial agents. 252932-48-2 belongs to class esters-buliding-blocks, and the molecular formula is C7H10N2O2, Category: esters-buliding-blocks.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Zhang, Junjie; Wang, Huanxia; Ma, Yun; Wang, Youming; Zhou, Zhenghong; Tang, Chuchi published the artcile< CaF2 catalyzed SN2 type chlorodehydroxylation of chiral secondary alcohols with thionyl chloride: a practical and convenient approach for the preparation of optically active chloroalkanes>, Category: esters-buliding-blocks, the main research area is chloroalkane chiral preparation; calcium fluoride catalyst chlorodehydroxylation chiral secondary alc thionyl chloride.

A CaF2 catalyzed chlorodehydroxylation of chiral secondary alcs. with thionyl chloride has been developed. The chlorination reaction is effective for a wide range of alcs., generating the corresponding chloroalkanes in good yield with high optical purity with inversion of the original configuration of the alc.

Tetrahedron Letters published new progress about Chlorination. 617-55-0 belongs to class esters-buliding-blocks, and the molecular formula is C6H10O5, Category: esters-buliding-blocks.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Chen, Guihua; Cao, Jian; Wang, Qian; Zhu, Jieping published the artcile< Desymmetrization of Prochiral Cyclopentenes Enabled by Enantioselective Palladium-Catalyzed Oxidative Heck Reaction>, HPLC of Formula: 30095-98-8, the main research area is desymmetrization cyclopentene enantioselective oxidative Heck palladium catalyst; oxidative Heck arylboronic acid cyclopentene palladium catalyst diastereoselective enantioselective.

In the presence of a catalytic amount of Pd(TFA)2 and a chiral Pyox ligand under oxygen atm., oxidative Heck reaction between arylboronic acids and 4-substituted or 4,4-disubstituted cyclopent-1-enes afforded the chiral arylated products with concurrent creation of two stereocenters in good yields with excellent diastereo- and enantioselectivities.

Organic Letters published new progress about Arylboronic acids Role: RCT (Reactant), RACT (Reactant or Reagent). 30095-98-8 belongs to class esters-buliding-blocks, and the molecular formula is C9H9NO4, HPLC of Formula: 30095-98-8.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Dinca, Emanuela; Hartmann, Philip; Smrcek, Jakub; Dix, Ina; Jones, Peter G.; Jahn, Ullrich published the artcile< General and Efficient α-Oxygenation of Carbonyl Compounds by TEMPO Induced by Single-Electron-Transfer Oxidation of Their Enolates>, Formula: C6H10O5, the main research area is alpha oxygenated carbonyl compound preparation; regioselective oxygenation carbonyl compound single electron transfer oxidation; stable free radical TEMPO coupling carbonyl compound; piperidinyloxy ketone ester amide acid nitrile preparation; enolate aggregate influence oxygenation reactions significantly; chemoselective reduction piperidinyloxy compound; hydroxy alpha carbonyl compound preparation; monoprotected diol preparation; amino alc protected preparation.

A generally applicable method for the synthesis of protected α-oxygenated carbonyl compounds is reported. It is based on the single-electron-transfer oxidation of easily generated enolates to the corresponding α-carbonyl radicals. Coupling with the stable free radical TEMPO provides α-(piperidinyloxy) ketones, esters, amides, acids or nitriles in moderate-to-excellent yields. Enolate aggregates influence the outcome of the oxygenation reactions significantly. Competitive reactions have been analyzed and conditions for their minimization are presented. Chemoselective reduction of the products led to either N-O bond cleavage to α-hydroxy carbonyl compounds or reduction of the carbonyl functionality to monoprotected 1,2-diols or O-protected amino alcs.

European Journal of Organic Chemistry published new progress about Aldehydes Role: RCT (Reactant), RACT (Reactant or Reagent) (enolization and TEMPO-induced single-electron-transfer oxidation of). 617-55-0 belongs to class esters-buliding-blocks, and the molecular formula is C6H10O5, Formula: C6H10O5.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Listowsky, Irving; Avigad, Gad; Englard, Sasha published the artcile< Conformational equilibria and stereochemical relations among carboxylic acids>, HPLC of Formula: 617-55-0, the main research area is acyclic acid conformation; conformation acyclic acid; circular dichroism acyclic acid.

The CO spectra of certain acyclic carboxylic acids were surveyed in an effort to study their conformation in solution In aqueous solution the spectra of many α-hydroxy acids were characterized by two overlapping ellipticity bands; a weak one in the 240-mμ spectral region and a more intense one of opposite sign near 210 mμ. At elevated temperatures or in solvents of low dielec. constant, the band of longer wavelength increased in intensity with an attendant decrease in the short-wavelength band. These properties are compatible with the presence of two structural species in equilibrium, and could be related to the contributions of specific rotational isomers of the acids. Conformations with the hydroxyl and carbonyl groups in an eclipsed alignment are designated as preferred. In contrast to the α-hydroxy acids, carboxylic acids with α-alkyl substituents generally showed only a single dichroic band centered near 210 mμ. In general, coplanarity of the carboxyl group and α-substituents was assumed, and interpretations in terms of the preferred orientation of substituents adjacent to the carboxyl group are suggested. The proposed population of rotational isomers was consistent with the observed effects of solvent polarity, temperature, polarity of substituents, and predicted steric interactions. An empirical rule relating the sign of ellipticity and the conformation of these classes of carboxylic acids was applied.

Journal of Organic Chemistry published new progress about Acids Role: PRP (Properties). 617-55-0 belongs to class esters-buliding-blocks, and the molecular formula is C6H10O5, HPLC of Formula: 617-55-0.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Muraoka, Osamu; Toyooka, Naoki; Ohshima, Yumiko; Narita, Norihiko; Momose, Takefumi published the artcile< Synthesis of natural (S)-(-)-tulipalin B starting from L-malic acid as a chiral pool>, Recommanded Product: (S)-Dimethyl 2-hydroxysuccinate, the main research area is tulipalin B total synthesis enantioselectivity; malic acid chiral synthon tulipalin B.

Naturally occurring tulipalin B (I) was prepared enantioselectively from chiral synthon L-malic acid (II) in 15% yield.

Heterocycles published new progress about Chiral synthons. 617-55-0 belongs to class esters-buliding-blocks, and the molecular formula is C6H10O5, Recommanded Product: (S)-Dimethyl 2-hydroxysuccinate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Strazzolini, Paolo; Verardo, Giancarlo; Gorassini, Fausto; Giumanini, Angelo G. published the artcile< Orientation effect of side chain substituents in aromatic substitution. Induced ortho nitration>, Application In Synthesis of 30095-98-8, the main research area is ortho nitration toluene derivative regiochem; benzeneacetic acid ortho nitration.

The presence of a free carboxyl or ester function on the α-carbon of toluene induces the nitration of the Ph ring in the ortho position at or above the statistical value (chaperon effect), when pure HNO3 is used in CH2Cl2 solution This is at variance with the results of classical nitration in H2SO4, where p-nitration predominates by far and m-nitration occurs to a remarkable extent. The new finding is explained in terms of precomplex formation.

Bulletin of the Chemical Society of Japan published new progress about Nitration. 30095-98-8 belongs to class esters-buliding-blocks, and the molecular formula is C9H9NO4, Application In Synthesis of 30095-98-8.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Roy, Sourav; Kumar, Gourav; Chatterjee, Indranil published the artcile< Photoinduced Diverse Reactivity of Diazo Compounds with Nitrosoarenes>, HPLC of Formula: 94-02-0, the main research area is nitrosobenzene aralkyl diazoacetate oxygen transfer photochem; alkyl oxo aryl acetate preparation; nitrosoarene aralkyl diazoacetate regioselective cycloaddition photochem; aralkyl oxazetidinone preparation.

A diverse reactivity of diazo compounds with nitrosobenzene in an oxygen-transfer process and a formal [2 + 2] cycloaddition was reported. Nitosoarene was exploited as a mild oxygen source to oxidize an in-situ generated carbene intermediate under visible-light irradiation UV-light-mediated in-situ generated ketenes reacted with nitosobenzenes to deliver oxazetidine derivatives These operationally simple processes exemplify a transition-metal-free and catalyst-free protocol to give structurally diverse α-ketoesters or oxazetidines.

Organic Letters published new progress about [2+2] Photocycloaddition reaction. 94-02-0 belongs to class esters-buliding-blocks, and the molecular formula is C11H12O3, HPLC of Formula: 94-02-0.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Rodenko, Boris; Toebes, Mireille; Hadrup, Sine Reker; van Esch, Wim J. E.; Molenaar, Annemieke M.; Schumacher, Ton N. M.; Ovaa, Huib published the artcile< Generation of peptide-MHC class I complexes through UV-mediated ligand exchange>, Computed Properties of 30095-98-8, the main research area is peptide complex MHC class I UV exchange.

Major histocompatibility complex (MHC) class I mols. present peptide ligands on the cell surface for recognition by appropriate cytotoxic T cells. MHC-bound peptides are critical for the stability of the MHC complex, and standard strategies for the production of recombinant MHC complexes are based on in vitro refolding reactions with specific peptides. This strategy is not amenable to high-throughput production of vast collections of MHC mols. The authors have developed conditional MHC ligands that form stable complexes with MHC mols. but can be cleaved upon UV irradiation The resulting empty, peptide-receptive MHC mols. can be charged with epitopes of choice under native conditions. Here the authors describe in-depth procedures for the high-throughput production of peptide-MHC (pMHC) complexes by MHC exchange, the anal. of peptide exchange efficiency by ELISA and the parallel production of MHC tetramers for T-cell detection. The production of the conditional pMHC complex by an in vitro refolding reaction can be achieved within 2 wk, and the actual high-throughput MHC peptide exchange and subsequent MHC tetramer formation require less than a day.

Nature Protocols published new progress about CD8-positive T cell. 30095-98-8 belongs to class esters-buliding-blocks, and the molecular formula is C9H9NO4, Computed Properties of 30095-98-8.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics