5845-53-4Relevant academic research and scientific papers
Synthesis and host-guest studies of chiral N-linked peptidoresorc[4]arenes
Botta, Bruno,D'Acquarica, Ilaria,Delle Monache, Giuliano,Subissati, Deborah,Uccello-Barretta, Gloria,Mastrini, Massimo,Nazzi, Samuele,Speranza, Maurizio
, p. 9283 - 9290 (2007)
(Figure Presented) Four cone resorc[4]arene octamethyl ethers (10, 11, ent-10, and ent-11) tetrafunctionalized at the feet with valyl-leucine [LL- (6); DD- (ent-6)] and leucyl-valine [LL- (9); DD- (ent-9)] methyl esters have been synthesized. These compounds, obtained by conjugation of macrocycle tetracarboxylic acid chlorides with the appropriate terminal amino groups of the above dipeptides, are N-linked peptidoresorc[4]arenes. We found that these macrocycles (M) are capable of recognizing the homologue dipeptides as guests (G), both in solution and in the gas phase, by forming relatively stable host-guest complexes ([M·G]), resistant to chromatographic purification but not to heating. Complexation phenomena between M and G in solution were investigated by NMR methods, including NMR DOSY experiments, for the detection of translational diffusion. Heteroassociation constants of 2030 and 186 M -1 were obtained by the Foster-Fyfe method for the complexes [10·6] and [10·ent-6], respectively, the latter being comparable to the self-association constant of dipeptide itself. Conversely, the structural features of the proton-bound complexes [M·H·Gn] + (n = 1, 2), generated in the gas phase by electrospray ionization mass spectrometry (ESI-MS), were investigated by collision-induced dissociation (CID) experiments. In both cases, the four N-linked peptidoresorc[4]arenes were shown to act as synthetic receptors and to recognize the homologue dipeptide by means of hydrogen bonds.
Convenient method for the synthesis of some novel chiral methyl 2-(2-oxo-2H-benzo[e][1,3]oxazin-3(4H)-yl)propanoate derivatives and biological evaluation of their antioxidant, cytotoxic, and molecular docking properties
Matam, Sivakumar,Kaliyan, Prabakaran,Selvaraj, Loganathan,Muthu, Seenivasa Perumal,Lohanathan, Bharathi Priya,Viswanadhan, Vijaya Padma,Makala, Himesh,Venkatasubramanian, Ulaganathan
supporting information, p. 569 - 579 (2020/12/11)
Ten chiral methyl 2-(2-oxo-2H-benzo[e][1,3]oxazin-3(4H)-yl)propanoate derivatives 6a-6j have been synthesized from optically pure amino methyl phenol 5 and 4-nitrophenyl chloroformate. These derivatives 6a-6j are characterized by 1H NMR, 13C NMR, FT-IR, and HRMS spectral techniques. Optical purity of these derivatives was confirmed by chiral HPLC method. Ten synthesized ester derivatives 6a-6j were screened for their in vitro antioxidant activity. Among the compounds 6b-d and 6h-j have exhibited comparable antioxidant activity with ascorbic acid as a standard. Compounds 6a and 6e-g have shown moderate antioxidant activity. Further, the in vitro cytotoxicity of these compounds were studied through MTT cell proliferation assay in addition the effect on LDH leakage and NO release. Among the derivatives, 6j showed extremely best activity and the IC50 value (12.54 ± 0.71 μM) is very close to doxorubicin (7.2 ± 0.58 μM) as a standard. Compounds 6b, 6h, and 6i showed better inhibition next to compound 6j on the viability of HepG2 cells with an IC50 value (μM) of 56.02 ± 1.4, 41.76 ± 0.58, and 38.17 ± 0.34, respectively. Also, molecular docking studies have been carried out with STAT-3 (PDB ID: 1BG1) and BCL-2 (PDB ID: 4AQ3) proteins against the four active compounds 6b, 6h, 6i, and 6j. The binding energies of the tested compounds were in the range of ?7.76 to ?8.41 kcal/mol, which is very close to doxorubicin (?8.53 kcal/mol) as a standard. These molecular docking results are in good agreement with the in vitro studies.
Photochemical Deracemization at sp3-Hybridized Carbon Centers via a Reversible Hydrogen Atom Transfer
Bach, Thorsten,Breitenlechner, Stefan,Gro?kopf, Johannes,Plaza, Manuel,Seitz, Antonia,Storch, Golo
supporting information, p. 21241 - 21245 (2021/12/27)
A photochemical deracemization of 5-substituted 3-phenylimidazolidine-2,4-diones (hydantoins) is reported (27 examples, 69%-quant., 80–99% ee). The reaction is catalyzed by a chiral diarylketone which displays a two-point hydrogen bonding site. Mechanistic evidence (DFT calculations, radical clock experiments, H/D labeling) suggests the reaction to occur by selective hydrogen atom transfer (HAT). Upon hydrogen binding, one substrate enantiomer displays the hydrogen atom at the stereogenic center to the photoexcited catalyst allowing for a HAT from the substrate and eventually for its conversion into the product enantiomer. The product enantiomer is not processed by the catalyst and is thus enriched in the photostationary state.
N-1 BRANCHED ALKYL SUBSTITUTED IMIDAZO[4,5-C]QUINOLINE COMPOUNDS, COMPOSITIONS, AND METHODS
-
Page/Page column 65, (2020/12/29)
Imidazo[4,5-c]quinoline compounds having a substituent that is attached at the N-1 position by a branched group, single enantiomers of the compounds, pharmaceutical compositions containing the compounds, and methods of making the compounds are disclosed. Methods of use of the compounds as immune response modifiers, for inducing (or inhibiting) cytokine biosynthesis in humans and animals, and in the treatment of diseases including infectious and neoplastic diseases are also disclosed.
Cocrystallization of Chiral N7,N16-bis (S-1-Phenylethyl)-1,4,10,13-Tetraoxo-7,16-Diazacyclooctadecane-7,16-Dicarboxamide with Hydrochlorides of Methyl Ethers of Leucine and Valine Enantiomers
Fonari,Pluzhnik-Gladyr,Kamalov,Kravtsov, V. Kh.
, p. 143 - 150 (2019/04/30)
An attempt to co-crystallize N7,N16-bis(S-1-phenylethyl)-1,4,10,13-tetraoxo-7,16-diazacyclooctadecane-7,16-dicarboxamide (1) with hydrochlorides of methyl ethers (HCMEs) of L- and D-valine and also L- and D-leucine results in separate crystallization of diazacrown-ether 1 (or its monohydrate 1·H2O) and HCMEs of respective α-amino acids. Crystal structures of D-leucine 1·H2O (1) and HCME (2) compounds, which were not described previously, are solved by single crystal X-ray diffraction.
Rhodium-Catalyzed Enantioselective Synthesis of Oxazinones via an Asymmetric Ring Opening-Lactonization Cascade of Oxabicyclic Alkenes
Yen, Andy,Pham, Anh Hoang,Larin, Egor M.,Lautens, Mark
supporting information, p. 7549 - 7553 (2019/10/02)
The rhodium-catalyzed asymmetric ring opening reaction of oxabicyclic alkenes is shown to be an efficient method for synthesizing chiral heterocycles. We demonstrate that the pairwise combination of chiral catalyst with chiral amino-acid-derived pronucleophiles results in a stereodivergent synthesis of diastereomeric hydroxyesters. A favorable conformational preference induces the subsequent lactonization of one diastereomer leading to the highly enantioselective synthesis of oxazinones.
Synthesis of a novel category of pseudo-peptides using an Ugi three-component reaction of levulinic acid as bifunctional substrate, amines, and amino acid-based isocyanides
Khalesi, Maryam,Halimehjani, Azim Ziyaei,Martens, Jürgen
supporting information, p. 852 - 857 (2019/04/17)
The synthesis of a novel category of pseudo-peptides via intramolecular Ugi reaction of levulinic acid (4-oxopentanoic acid), aromatic and aliphatic amines, and amino acid-based isocyanides is reported. Levulinic acid was applied as a bifunctional substrate containing both carbonyl and acid moieties suitable for the Ugi reaction. This article provides a facile and convenient one-pot procedure for the synthesis of peptide-like heterocyclic molecules containing 2-pyrrolidone (γ-lactam), amide and ester functional groups with good to excellent yields.
N-Heterocyclic Carbene Iron(III) Porphyrin-Catalyzed Intramolecular C(sp3)–H Amination of Alkyl Azides
Shing, Ka-Pan,Liu, Yungen,Cao, Bei,Chang, Xiao-Yong,You, Tingjie,Che, Chi-Ming
supporting information, p. 11947 - 11951 (2018/09/11)
Metal-catalyzed intramolecular C?H amination of alkyl azides constitutes an appealing approach to alicyclic amines; challenges remain in broadening substrate scope, enhancing regioselectivity, and applying the method to natural product synthesis. Herein we report an iron(III) porphyrin bearing axial N-heterocyclic carbene ligands which catalyzes the intramolecular C(sp3)–H amination of a wide variety of alkyl azides under microwave-assisted and thermal conditions, resulting in selective amination of tertiary, benzylic, allylic, secondary, and primary C?H bonds with up to 95 % yield. 14 out of 17 substrates were cyclized selectively at C4 to give pyrrolidines. The regioselectivity at C4 or C5 could be tuned by modifying the reactivity of the C5–H bond. Mechanistic studies revealed a concerted or a fast re-bound mechanism for the amination reaction. The reaction has been applied to the syntheses of tropane, nicotine, cis-octahydroindole, and leelamine derivatives.
A valsartan synthesis method of alkylation impurity (by machine translation)
-
Paragraph 0019-0020, (2018/10/19)
A valsartan synthesis method of alkylation impurities, is to L - valine that may exist in the impurity D - valine, alanine, leucine isoleucine amino acid as the raw material and the like, in thionyl chloride under the conditions of the esterification reaction with methanol, after the reaction by reducing pressure methanol, then with 2 - cyano - 4' - bromomethyl biphenyl in the reaction under alkaline conditions, after completion of the reaction, saturated salt water washing, adding hydrochloric acid to adjust the pH=1 - 2, the temperature of the crystallization, filtering to obtain the target product valsartan alkylation impurity. The present invention is to provide high-purity impurity, will its known impurity used for alkylation of valsartan in mass analysis, the position of the clear of impurities in the sample, the degree of impurity of the sample inspection, optimizes the analytical method, contribute to improving the quality of valsartan research, for the production of valsartan reducing impurity, improve the quality of the valsartan; at the same time, this invention has mild condition, the reaction yield is higher, convenient operation and the like. (by machine translation)
Synthesis and antiproteasomal activity of novel O-benzyl salicylamide-based inhibitors built from leucine and phenylalanine
Jorda, Radek,Du?ek, Jan,?ezní?ková, Eva,Pauk, Karel,Magar, Pratibha P.,Imramovsky, Ale?,Kry?tof, Vladimír
supporting information, p. 142 - 158 (2017/04/26)
Inhibition of protein degradation is one of strategies for suppression of uncontrolled proliferation of cancer cells. Proteolytic degradation in cells is mainly ensured by proteasome and its inhibition by bortezomib showed benefit in clinical use for the treatment of multiple myeloma. We report here the library of antiproteasomal O-benzyl salicylamides built from leucine and phenylalanine. Prepared compounds displayed antiproliferative activity on K562, CEM and U266 cancer cell lines, ranging from high micromolar to submicromolar GI50 values. The most potent compounds (series 4 and 6) were further assayed for their inhibition of chymotrypsin-like protease activity of the 26S proteasome in U266 cells. The majority of compounds inhibited the proteasome in mid-nanomolar concentrations (IC50 ranging from 57 to 197 nM) and it correlated with cellular potency. In a cell based assay involving green fluorescence protein (GFP) fused to a short degron that is rapidly degraded by a proteasome the compounds induced accumulation of GFP, visualised and quantified by live-cell imaging. Levels of polyubiquitinated proteins in U266 cells treated by compound 4m were also analyzed by immunoblotting, revealing a typical high molecular mass smear of ubiquitin conjugates. Finally, apoptotic cell death in treated U266 cells was detected biochemically by measuring the activity of caspases 3 and 7 in lysates and by immunoblotting of caspase 7, its substrate poly(ADP-ribose)polymerase, and Mcl-1, which all together showed changes typical for apoptosis. All these observations were in agreement with expected cellular mechanism of action and confirmed proteasome targeting by prepared O-benzyl salicylamides.
