3251-07-8

The fragmentation behavior of a novel thiourea-based cross-linker molecule specifically designed for collision-induced dissociation (CID) MS/MS experiments is described. The development of this cross-linker is part of our ongoing efforts to synthesize novel reagents, which create either characteristic fragment ions or indicative constant neutral losses (CNLs) during tandem mass spectrometry allowing a selective and sensitive analysis of cross-linked products. The new derivatizing reagent for chemical cross-linking solely contains a thiourea moiety that is flanked by two amine-reactive N-hydroxy succinimide (NHS) ester moieties for reaction with lysines or free N-termini in proteins. The new reagent offers simple synthetic access and easy structural variation of either length or functionalities at both ends. The thiourea moiety exhibits specifically tailored CID fragmentation capabilities - a characteristic CNL of 85 u - ensuring a reliable detection of derivatized peptides by both electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI) tandem mass spectrometry and as such possesses a versatile applicability for chemical cross-linking studies. A detailed examination of the CID behavior of the presented thiourea-based reagent reveals that slight structural variations of the reagent will be necessary to ensure its comprehensive and efficient application for chemical cross-linking of proteins. Copyright

The single-crystal X-ray diffraction analysis of a β,γ-hybrid model peptide Boc-β-Ala-γ-Abu-NH2 revealed the existence of four crystallographically independent molecules (A, B, C and D conformers) in the asymmetric unit. The analysis revealed t

Janadolide is a cyclic depsipeptide natural product isolated from the marine cyanobacterium Okeania sp. Herein, we describe the total synthesis of janadolide, along with eight simplified analogues, via an efficient solid-phase strategy. Crucial to the synthesis of the natural product was the construction of a key polyketide fragment via an enantioselective (-)-B-chlorodiisopinocampheylborane-mediated reduction and a B-alkyl Suzuki reaction. Janadolide and the simplified analogues exhibited antitrypanosomal activity against pathogenic Trypanosoma brucei rhodesiense and Trypanosoma cruzi parasites.

Application of a direct ring-closing approach which exploits an intramolecular aldol reaction with a ketene silyl acetal onto a remote imide function leading to the core skeleton of UCS1025A and B effectively provides access to small library of substituted analogues; of interest is their complete lack of antibacterial activity against MRSA (Gram+) and E. coli (Gram-) bacterial strains.

A transition metal-free approach for the N-arylation of amino acid derivatives has been developed. Key to this method is the use of unsymmetric diaryliodonium salts with anisyl ligands, which proved important to obtain high chemoselectivity and yields. The scope includes the transfer of both electron deficient, electron rich and sterically hindered aryl groups with a variety of different functional groups. Furthermore, a cyclic diaryliodonium salt was successfully employed in the arylation. The N-arylated products were obtained with retained enantiomeric excess.

In a preferred embodiment, there is provided a protecting group for protecting the thiol side chain of a cysteine residue, the protecting group comprising a Diels-Alder cycloadduct of a furan and a maleimide, and optionally, a linker interposed between the thiol side chain and the Diels-Alder cycloadduct.

Psammaplin A (PsA) is a bromotyrosine disulfide dimer with histone deacetylase (HDAC) inhibition and acts through reduced monomer PsA-SH. We studied the connection of HDAC inhibition, cell growth inhibition, and apoptosis induction of PsA-SH by modifying the -SH group with deletion (6a) or replacement with hydroxamic acid (10b) or benzamide (12g). PsA-SH inhibits HDAC1/2/3 and 6a loses the HDAC inhibition ability. 10b inhibits HDAC1/2/3/6 while 12g shows selective inhibition of HDAC3. PsA-SH and 10b, but neither 6a nor 12g, induce apoptosis in human leukemia HL-60 cells associated with increased acetylation of Histone H3. PsA-SH and 10b inhibit growth of several solid tumor cell lines in vitro and Lewis lung cancer cell growth in vivo. PsA-SH is a simple scaffold for developing selective HDAC inhibitors and induces apoptosis through inhibiting HDAC1/2.

The present invention is directed to compositions comprising N-Acetyl Methyl GABA, methods of preparing N-Acetyl Methyl GABA and compositions including N-Acetyl Methyl GABA, and methods of using N-Acetyl Methyl GABA for instance to improve sleep and control anxiety.

The invention relates to the field of styrene sulfone compounds and NLRP3 inhibitors, and particularly provides a styrene sulfone NLRP3 inflammasome inhibitor, a preparation method and application thereof, wherein the inhibitor is represented by a formula (1), n is selected from 0 and 1, X is selected from N and O, R1 is selected from different electron withdrawing or electron donating substituents, and R2 is selected from different fat or aromatic substituents. According to the invention, it is verified that the compounds represented by the general formula have NLRP3 inhibitory activity.

Inspired by the significant bioactivity of ergosterol peroxide, we designed and synthesized four fluorescent coumarin and ergosterol peroxide conjugates 8a-d through the combination of ergosterol peroxide with 7-N,N-diethylamino coumarins fluorophore. The cytotoxicity of synthesized conjugates against three human cancer cells (HepG2, SK-Hep1, and MCF-7) was evaluated. The results of fluorescent imaging showed that the synthesized conjugates 8a-d localized and enriched mainly in mitochondria, leading to significantly enhanced cytotoxicity over ergosterol peroxide. Furthermore, the results of biological functions of 8d showed that it could suppress cell colony formation, invasion, and migration; induce G2/M phase arrest of HepG2 cells, and increase the intracellular ROS level.

The invention discloses a resveratrol amino acid ester derivative and a preparation method thereof, and belongs to the technical field of fine chemical substance synthesis. The structure of the resveratrol amino acid ester derivative is represented by a formula shown in the description. The resveratrol amino acid ester derivative is synthesized from resveratrol, R amino acid, R' alcohol, dichlorosulfoxide and di(p-nitrobenzene) carbonate with 4-dimethylaminopyridine (DMAP) as a catalyst and acetonitrile as a solvent, wherein the R amino acid is one of alpha-alanine, beta-alanine and gamma-aminobutyric acid, and the R' alcohol is one of methanol, ethanol and n-propanol. The technical problem that resveratrol is difficult to preserve is solved, the pharmacological toxicity introduced by a resveratrol substituent group is lowered, and the resveratrol amino acid ester derivative has the pharmaceutical effects of resveratrol and amino acid. It is expected that the above novel compound playsa great role in beauty treatment and production of fatigue-relieving and blood pressure-lowering medicines.

A family of five benzene-1,3,5-tricarboxamide (BTA) compounds with varied side arm functionality [alkyl: n = 3, 4 and 5 chains; and ester and carboyxic acids] is reported. Investigations into their self-assembly behaviour revealed the extent to which mino

We aimed to design and synthesize novel γ-aminobutyric acid (GABA) derivatives with the combination of aspirin (ASA) of nerve rehabilitative pharmacophores so as to develop multifunctional drugs useful in the treatment of neurological disorders. Twenty-four novel esters and amides of 1a were synthesized, biologically evaluated for antiepileptic activity with the model of 4-aminopyridine (4-AP), and tested for their capacity of penetrating the blood-brain barrier (BBB) with HPLC. The distribution of 8a, ASA freed by 8a, 7c, and ASA freed by 7c within 24 h in brain tissue was measured. The structure-activity relationship (SAR) was established and the data of Computer Aided Drug Design (CADD) showed good results. With ED50 values of, 0.3684-0.5199 mmol/kg, LD50 1.1487-1.3944 mmol/kg, and therapeutic index (TI) 2.65-3.15, compounds 8a, 3b, 4b, 6c, and 7c exhibited better antiepileptic activities in multiples of 0.3 to 2.2 against the control sodium valproate (VPA). Most importantly, 8a and 7c exhibited excellent antiepileptic activities with TI values of, 3.15 and 3.12, respectively.

The polymetallic cation [Mo3S4(H2O) 9]4+ was used as an inorganic precursor to generate new hybrid organic-inorganic chalcogenide clusters. Three organic compounds with flexible and hanging arms were synthesized and investigated as ligands for coordination complexes with the rigid and electroactive inorganic {Mo 3S4} unit. Interestingly, the {Mo3S 4} core formed hybrid structures with the flexible H3NDABu [N-(3-carboxypropyl)iminodiacetic acid] and H3NDAPr [N-(2-carboxyethyl)iminodiacetic acid] ligands, which were characterized by X-ray crystallography. Surprisingly, no crystals were isolated, when the more rigid H3NDABn [N-(4-methoxycarbonylbenzyl)iminodiacetic acid] ligand was used. The two coordination complexes [Mo3S4(NDABu) (HNDABu)2]3- and [Mo3S4(HNDAPr) 3]2- were characterized by X-ray diffraction (XRD), IR spectroscopy, thermal gravimetric analysis (TGA), 1H NMR spectroscopy, elemental analysis, and electrochemistry. The organic ligands H3NDABu, H3NDAPr, and H3NDABn were characterized by XRD, IR, HR mass, and 13C and 1H NMR spectroscopy. [Mo3S4(NDABu)(HNDABu)2] 3- and [Mo3S4(HNDAPr)3]2- constitute promising preformed building blocks to generate new organic-inorganic hybrid molecular or extended materials. Two new promising preformed building blocks [Mo3S4(NDABu)(HNDABu) 2]3- and [Mo3S4(HNDAPr) 3]2- have been obtained. Their syntheses and characterizations are described. Copyright

The objective was to evaluate the potential of drug conjugates with l-carnitine as prodrugs that target organic cation/carnitine transporter (OCTN2). Twenty-two l-carnitine analogues were evaluated for human organic cation/carnitine transporter (hOCTN2) inhibition; the 3'-hydroxyl group was found to be the only functional group not contributing to l-carnitine interaction with hOCTN2 among the three functional groups on l-carnitine (i.e., 3'-hydroxyl, amine, and carboxylate). The 3'-hydroxyl group on l-carnitine was therefore chosen as the conjugate site. Three drug-l-carnitine conjugates (i.e., valproyl-l-carnitine, naproxen-l-carnitine, and ketoprofen-l-carnitine) were synthesized along with two ketoprofen analogues that incorporated a linker group (glycolic acid or glycine) between ketoprofen and l-carnitine (i.e., ketoprofen-glycolic acid-l-carnitine and ketoprofen-glycine-l-carnitine). These potential prodrugs were evaluated for their in vitro inhibition, transport, and metabolism properties. All three drug-l-carnitine conjugates and ketoprofen-glycine-l-carnitine were OCTN2 inhibitors, as well as substrates. For valproyl-l-carnitine, Ki = 155± 19μM, Km = 132± 23μM, and normalized Jmax = 0.467± 0.028; for naproxen-l-carnitine, Ki = 5.97± 0.81μM, Km = 257± 57μM, and normalized Jmax = 0.141± 0.012; for ketoprofen-l-carnitine, Ki = 82.2± 5.3μM, Km = 77.0± 4.0μM, and normalized Jmax = 0.412± 0.015; for ketoprofen-glycine-l-carnitine, Ki = 14.4± 1.4μM, Km = 58.5± 8.7μM, and normalized Jmax = 0.0789± 0.0037. Ketoprofen-glycolic acid-l-carnitine was unstable in metabolic buffers and chemical buffers. On the contrary, naproxen-l-carnitine, ketoprofen-l-carnitine, and ketoprofen-glycine-l-carnitine were stable in chemical and metabolic buffers. The results demonstrate the potential of drug-l-carnitine conjugates to serve as prodrugs that target OCTN2.

The supramolecular organogelation of alcohols was observed in relatively hydrophobic amphiphiles with a short oligo(ethylene glycol) unit and three long alkyl chains at room temperature, while the hydrogelation occurred in more hydrophilic gelators with a longer poly(ethylene glycol) unit and two long alkyl chains at various temperatures. When a hot aqueous solution of some of the synthetic hydrogelators was cooled down, the supramolecular hydrogel was formed at room temperature. In some other amphiphiles with less intermolecular interactivity in water at room temperature, a reverse phase transition of sol to gel was observed by elevating the temperature of their aqueous systems, especially below a physiological temperature, 37 °C. The supramolecular hydrogelation at a low or high temperature was dependent on a slight molecular modification of the synthetic amphiphiles.

Compounds represented by Formula (I) or Formula (II) against cell releasing TNFα, their pharmaceutically acceptable salts or hydrates and preparation methods and uses thereof, in which A and B represent CH2, CO, SO, or SO2; D represents S, NH, or NC1-6 alkyl; R1 represents H, or one or two same or different radical(s) selected from the group consisting of F, Cl, Br, C1-4 alkyl,OH,OC1-4 alkyl,NO2,NHC(O)C1-4 alkyl,NH2,NH(C1-4 alkyl), or N(C1-4 alkyl)2.

(Chemical Equation Presented) Because of the nitrogen functionality, the azido group plays an important role in the synthesis of amines, and numerous reduction methods of azides to primary amines are reported. Recent reports have highlighted the capability of NaI as a useful reagent for this transformation when it is used in combination with a Lewis acid promoter. However, these methods often suffer from harsh reaction conditions; for this reason, the development of a simple and efficient protocol using NaI in presence of inexpensive and readily available cerium salts Lewis acids would extend the scope of this organic transformation. In continuation of our interest on the use of the CeCl3·7H2O/NaI system, in this paper we report how azides undergo reduction by NaI in the presence of CeCl 3·7H2O in refluxing acetonitrile under neutral conditions to produce the corresponding primary amines. The rate and yield of the reaction are considerably improved by employing this microwave-assisted procedure, and this may be of value for the preparation of densely functionalized molecules having biological and pharmaceutical activities.

A novel cytotoxic butenolide alkaloid, uncinine, has been synthesized for the first time in 8 steps from propargyl alcohol. The sequence features a mild and efficient tandem carbonylative lactonization of a β-iodoenone precursor using an inorganic base at 1 atm CO, and an indirect attachment of the pyrrolidinone ring via nucleophilic substitution with methyl γ-aminobutyrate.

Facile synthesis of cis-2-aryl-3-pyrrolidine carboxylates from readily accessible γ-imino esters by intramolecular cyclization mediated by a TiCl4/Et3N reagent system is described.

The use of a compound of formula (I) 1 or a salt, ester or amide thereof; where X is O, or S, S(O) or S(O)2, or NR6 where R6 is hydrogen or C1-6 alkyl,; R5 is an optionally substituted 5-membered heteroaromatic ring, R1, R2 ,R3, R4 are independently selected from various specified moieties, in the preparation of a medicament for use in the inhibition of aurora 2 kinase. Certain compounds are novel and these, together with pharmaceutical compositions containing them are also described and claimed

Aliphatic and aromatic nitro compounds are selectively and rapidly reduced to their corresponding amino derivatives in good yields using ammonium formate and commercial zinc dust. This system is found to be compatible with several sensitive functionalities such as halogens, -OH, -OCH3, -CHO, -COCH3, -COC6H5, -COOH, COOC2H5, -CONH2, -CN, -CH=CH-COOH, -NHCOCH3. The reduction can be carried out not only with HCOONH4 but also with HCOOH.

A novel methodology is reported for construction of active sites of artificial multinuclear metalloenzymes: Transfer of metal-chelating sites confined in a prebuilt cage to a polymeric backbone. Artificial active sites comprising two or three moieties of Cu(II) complex of tris(2-aminoethyl)amine (tren) were prepared by transfer of Cu(II)tren units confined in a molecular bowl (MB) to poly(chloromethylstyrene-co-divinylbenzene) (PCD). By treatment of unreacted chloro groups of the resulting PCD with methoxide and destruction of the MB moieties attached to PCD with acid followed by addition of Cu(II) ion to the exposed tren moieties, catalytic polymers with peptidase activity were obtained. The average number (β) of proximal Cu(II)tren moieties in the active site of the artificial multinuclear metallopeptidase was determined by quantifying the Cu(II) content. Several species of the artificial metallopeptidases with different β contents were prepared and examined for catalytic activity in hydrolysis of various cinnamoyl amide derivatives. The PCD-based catalytic polymers did not hydrolyze a neutral amide but effectively hydrolyzed carboxyl-containing amides (N-cinnamoyl glycine, N-cinnamoyl β-alanine, and N-cinnamoyl γ-amino butyrate). Analysis of the kinetic data revealed that the active sites comprising three Cu(II)tren units were mainly responsible for the catalytic activity. When analyzed in terms of k(cat), the catalytic activity of the PCD-based artificial peptidase was comparable to or better than the catalytic antibody with the highest peptidase activity reported to date. A mechanism is suggested for the effective cooperation among the three metal centers of the active site in hydrolysis of the carboxyl-containing amides.

Several trials were made for the syntheses of (S)-4-hydroxy-pyrrolidin- 2-one ((S)-HPD) and (R)-4-mercapto-pyrrolidin-2-one ((R)-MPD), a substituent at the 2-position of the orally active carbapenem antibiotic CS-834. The latter was synthesized from prochiral dimethyl or diethyl 3-p- methoxybenzylthioglutarate using pig liver esterase technology to give monoester with an optical purity of 51-71% e.e. as a key intermediate.

Modified cell-wall peptides have been rationally designed and studied in a semi-quantitative approach to factorising free energy contributions in binding to vancomycin-group antibiotics in aqueous solution. Binding energies for succinyl and fumaryl-D-Ala dipeptides. and N-oxalyl-γ-aminobutyric acid analogues, are compared with binding energies for the natural substrate N-Ac-D-Ala-D-Ala, and the truncated mono-peptide N-Ac-D-Ala. We estimate the binding energy of the N-terminal carboxyl group, by four independent analyses, to he -(14 to 17)±7 kJ mol-1 when differences in ligand binding energies are corrected for differences in contributions from the "cost" of restricting rotations and "benefits" of hydrophobic interactions. The carboxylate interaction comprises both a charged - COO-...HN hydrogen bond plus face to face π-stacking between the carboxylate group and an aromatic ring in the antibiotic binding pocket.

Exclusive formation of amino acid esters took place at an appreciable rate in the CuII-catalysed solvolysis of 6,6'-(α-alanylamino or α-phenylalanylamino)-2,2'-bipyridine in alcohol-borate buffer (pH 7.2) solutions at 20 deg C via formation of an amide-O-coordinated complex, even though appreciable amounts of water (0-40percent v/v) were present in the solution.

It has been found that N-trimethylsilylmethylamine reacts with unsymmetrical dipolarophiles to give 2,2,4- or 2,2,3-trisubstituted pyrrolidines in the presence of tetrabutylammonium fluoride or fluoroacetic acid, respect

Various nitroesters 3 were selectively and rapidly reduced to their corresponding amino esters 4 in very good yield using anhydrous ammonium formate as a catalytic hydrogen transfer agent.

N-(Silylmethyl)imines generate N-protonated azomethine ylides of nonstabilized type when treated with water in HMPA, which undergo stereospecific and regioselective cycloadditions with electron-poor olefins affording N-unsubstituted pyrrolidines.On the other hand, fluoride-induced desilylation of the imines leads to 2-azallyl anions which are found to be synthetic equivalents of aminomethyl anion in the Michael additions with electron-poor olefins and nucleophilic additions with carbonyl compounds.

Further studies have demonstrated that the site-specific hydrogen transfer process involved in the formation of the m/z 145 anion of β-hydroxyamine pentafluoropropionate (PFP) derivatives observed under electron capture negative ion chemical ionization conditions occurs when the two functional groups are separated by up to five carbon atoms.Deuterium labelling has established that the site specificity, transfer of a hydrogen atom from the carbon adjacent to nitrogen to the OPFP group, is maintained in 4-amino-butan-1-ol-N,O-(PFP)2.The corresponding PFP derivatives of the N-methylaminoalkanol- (PFP)2 derivatives lack the m/z 145 species with m/z 163, -, being the base anion.Substitution of alkyl groups on the carbon adjacent to oxygen results in a diminution of the ion intensity at m/z 145 with a marked increase in the intensity of m/z 144.The formation of the m/z 145 and 144 anions is proposed to proceed through the intervention of a fluoride ion-molecule complex as outlined in Scheme 1 with the product ion distribution dependent on which of the two pathways is preferred.

The hydrolysis rate of the ester bond in the molecules of methyl esters of the N-retinylidene derivatives of aliphatic amino acids depends on their chain lengths.The higher reaction rates for the derivatives of γ-aminobutyric and δ-aminovaleric acids are explained by intramolecular catalysis.

Various aliphatic and aromatic nitro compounds were selectively and rapidly reduced to their corresponding amino derivatives in very good yield using anhydrous ammonium formate as a catalytic hydrogen transfer agent.