排序方式: 共有101条查询结果,搜索用时 15 毫秒
11.
Cost effective and green protocols for the synthesis of two new series of coumarin based blue light emitting fluorophores named as ‘Beta Fluors’ and ‘Alpha Fluors’ are described. The coumarin alkylamide based Beta Fluors are developed using a one-step multi-component process in the presence of phenyl boronic acid as an efficient green catalyst. The Alpha Fluors are structured with coumarin–triazole–carboxamide peptidomimetics and their synthesis involves the ‘click with MCR’ concept. The new fluorophores gave high Stoke’s shift values for the emission wavelengths and their structural features are promising for further fine tuning to obtain preferred emission maxima. 相似文献
12.
Carlo Bonini Lucia Chiummiento Margherita De Bonis Maria Funicello Paolo Lupattelli 《Tetrahedron letters》2004,45(13):2797-2799
A stereoselective and efficient preparation of a thiophene containing intermediate 2 from ethyl 3-thienyl propenoate 4 as the core of new possible HIV protease inhibitors is described. The chiral intermediate has been successfully used for the preparation of the analog 1 of the potent HIV inhibitor nelfinavir. 相似文献
13.
Francesco Peri Laura Cipolla Eleonora Forni Francesco Nicotra 《Monatshefte für Chemie / Chemical Monthly》2002,133(4):369-382
Summary. The polyfunctionality and conformational rigidity of carbohydrates make this class of compounds ideal scaffolds for the production
of sortiments1 of bioactive compounds. Examples of carbohydrate-derived peptidomimetics of biological interest, such as somatostatin agonists
and integrin antagonists, are presented. In order to have access to solid phase supported sortiments of compounds, orthogonally
protected or unprotected carbohydrates were linked to polymers and reacted in the solid phase employing different regioselective
strategies. Original bicyclic and tricyclic glycidic scaffolds were easily obtained starting from natural sugars such as D-arabinose and D-fructose. Manipulation of these conformationally blocked compounds afforded different carbohydrate-based derivatives, among
which azidoacids are useful precursors of β-turn peptidomimetics.
Received September 10, 2001. Accepted November 2, 2001 相似文献
14.
The synthesis of two oligomers, of a bifunctional diketopiperazine scaffold DKP-1, formally derived from the cyclization of l-aspartic acid and (S)-2,3-diaminopropionic acid, is reported. A trimeric and a tetrameric structure were prepared by solution-phase peptide synthesis (Boc strategy). Conformational analysis of these derivatives was carried out by a combination of 1H NMR spectroscopy, CD spectroscopy, and molecular modeling, and revealed the formation of β-bend ribbon involving 10-membered H-bonded rings and a reverse turn of the growing peptide chain. 相似文献
15.
Mickael Virlouvet 《Tetrahedron》2010,66(32):6174-6180
Protected diaminoalcohols obtained through allyl addition to α-amino acid-derived imines and subsequent hydroboration were used for the preparation of pyrrolidinones and pyrrolidines. Pyrrolidinones were synthesized with moderate yields by oxidation of the hydroxy function with tetrapropylammonium perruthenate/N-methylmorpholine-N-oxide and concomitant cyclization while pyrrolidines were synthesized in good yields by tosylation of the hydroxy group and subsequent intramolecular nucleophilic substitution. Thus accessible substrates were transferred into peptidomimetics by attachment of amino acid moieties at both termini using conventional peptide coupling strategies. Molecular mechanics optimizations suggest that these substrates preferentially adopt a turn conformation. 相似文献
16.
N. Narendra 《Tetrahedron letters》2010,51(47):6169-6173
A simple protocol for the synthesis of a new class of trithiocarbonate-linked peptidomimetics and neoglycosylated amino acids is described. N-Protected amino alkyl thiols were treated with CS2 in the presence of triethylamine (TEA) to generate trithiocarbonate salt, which upon reaction with appropriate halides afforded dipeptidomimetics in good yields. Further, the procedure was also extended for the synthesis of N,N′-orthogonally protected trithiocarbonate-linked dipeptidomimetics. 相似文献
17.
An unprecedented chiral spiropiperidine oxindole system was synthesized starting from enantiopure quaternary 3-aminooxindole and relying on a ring closing metathesis as the key step. This compound acts as an highly constrained Freidinger γ-lactam, adopting a type II β-turn conformation in solution, as assessed by modelling and spectroscopical studies. 相似文献
18.
N-Phthalimido β-aminoethanesulfonyl chlorides, new building blocks for the synthesis of peptidosulfonamide peptidomimetics, were prepared in a straightforward manner from amino acids. In the crucial synthetic step, sulfonic acids or their sodium salts were converted into the corresponding sulfonyl chlorides using an excess of refluxing thionyl chloride or thionyl chloride/DMF. This simple and effective chlorinating method is also applicable to β-aminoethane sulfonic acids and their sodium salts with other N-protecting groups. 相似文献
19.
Xiude Hua Liangliang Zhou Lu Feng Yuan Ding Haiyan Shi Limin Wang Shirley J. Gee Bruce D. Hammock Minghua Wang 《Analytica chimica acta》2015
Twenty-three phage-displayed peptides that specifically bind to an anti-benzothiostrobin monoclonal antibody (mAb) in the absence or presence of benzothiostrobin were isolated from a cyclic 8-residue peptide phage library. Competitive and noncompetitive phage enzyme linked immunosorbent assays (ELISAs) for benzothiostrobin were developed by using a clone C3-3 specific to the benzothiostrobin-free mAb and a clone N6-18 specific to the benzothiostrobin immunocomplex, respectively. Under the optimal conditions, the half maximal inhibition concentration (IC50) of the competitive phage ELISA and the concentration of analyte producing 50% saturation of the signal (SC50) of the noncompetitive phage ELISA for benzothiostrobin were 0.94 and 2.27 ng mL−1, respectively. The noncompetitive phage ELISA showed higher selectivity compared to the competitive. Recoveries of the competitive and the noncompetitive phage ELISAs for benzothiostrobin in cucumber, tomato, pear and rice samples were 67.6–119.6% and 70.4–125.0%, respectively. The amounts of benzothiostrobin in the containing incurred residues samples detected by the two types of phage ELISAs were significantly correlated with that detected by high-performance liquid chromatography (HPLC). 相似文献
20.
Dirk T.S. Rijkers Fernando de Prada LópezRob M.J. Liskamp François Diederich 《Tetrahedron letters》2011,52(51):6963-6967
We report on the chemoselective coupling between colorless peptide fragments functionalized with a mutually reactive electron-rich Nα-(4-ethynylphenyl)-Nα-(methyl)-glycyl- and an electron-deficient [4-(2,2-dicyanovinyl)]benzoyl moiety. The resulting donor-substituted 1,1-dicyanobuta-1,3-dienes represent a new class of orange-red colored (λmax = 450-500 nm, with molar extinction coefficients (ε) above 5,000 mol−1 dm3 cm−1) peptide-based imaging chromophores. 相似文献