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1.
Design, synthesis, and binding affinities of pyrrolinone-based somatostatin mimetics 总被引:1,自引:0,他引:1
Smith AB Charnley AK Mesaros EF Kikuchi O Wang W Benowitz A Chu CL Feng JJ Chen KH Lin A Cheng FC Taylor L Hirschmann R 《Organic letters》2005,7(3):399-402
[structure: see text] Tetrapyrrolinone somatostatin (SRIF) mimetics (cf. 1), based on a heterochiral (D,L-mixed) pyrrolinone scaffold, were designed, synthesized, and evaluated for biological activity. The iterative synthetic sequence, incorporating the requisite functionalized coded and noncoded amino acid side chains, comprised a longest linear synthetic sequence of 23 steps. Binding affinities at two somatostatin receptor subtypes (hsst 4 and 5) reveal micromolar activity, demonstrating that the d,l-mixed pyrrolinone scaffold can be employed to generate functional mimetics of peptide beta-turns. 相似文献
2.
Pier Luigi Ferrarini Claudio Mori Muwaffag Badawneh Clementina Manera Adriano Martinelli Federico Romagnoli Giuseppe Saccomanni Mauro Miceli 《Journal of heterocyclic chemistry》1997,34(5):1501-1510
Several 1,8-naphthyridine derivatives have been diazotizated to obtain the corresponding hydroxy derivatives or mixture of hydroxy and hydroxy nitro derivatives. The respective amounts of hydroxy and hydroxy nitro derivatives depends on the nature of the substituents, on their position on the naphthyridine nucleus, on the amount of sodium nitrite and on the reaction temperature. A study of the electronic density of some molecules suggests a possible explanation of the effects induced by the nature of the substituents and of their position. Some of the compounds were tested for their ability to inhibit human platelet aggregation in vitro induced by arachidonic acid. Only compound 26 showed interesting antiplatelet activity. 相似文献
3.
Giuliana Biagi Irene Giorgi Oreste Livi Clementina Manera Valerio Scartoni Pier Luigi Barili 《Journal of heterocyclic chemistry》1997,34(3):845-851
This paper continues the synthesis of new 1,2,3-triazolo[1,2-a]benzotriazoles or 2,3-benzo-1,3a,6,6a-tetrazapentalenes to submit to biological assays. The derivatives were obtained by deoxycyclization reactions of appropriate nitrophenyl-1,2,3-triazole derivatives and by thermal decomposition of appropriate azidophenyl-1,2,3-triazoles (Schemes 1 and 2). Some attempts to extend these synthetic routes to the preparation of 1,2,4-triazolo[1,2-a]benzotriazoles (Scheme 3) and 1,2,3-triazolo[1,2-b]-4H-1,2,3-benzo-triazines (Scheme 4) completely failed. 相似文献
4.
Giuliana Biagi Irene Giorgi Oreste Livi Clementina Manera Valerio Scartoni 《Journal of heterocyclic chemistry》1997,34(1):65-69
Some new 1,2,3-triazolo[4,5-d]-1,2,4-triazolo[4,3-b]pyridazines were prepared starting from the corresponding 1,2,3-triazolo[4,5-d]pyridazines via the formation of the 1,2,4-triazole ring, by condensation of an appropriate monocarbon fragment with the 4-hydrazino substituent and the nitrogen atom in the 5 position of the heterocycle. Condensation of 4-phenylhydrazino substituted derivatives with formic acid gave zwitterionic compounds. 相似文献
5.
Dr. Jeanette E. Stok Dr. Sharon Chow Dr. Elizabeth H. Krenske Clementina Farfan Soto Csongor Matyas Prof. Raymond A. Poirier Prof. Craig M. Williams Prof. James J. De Voss 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(13):4408-4412
The cytochromes P450 are hemoproteins that catalyze a range of oxidative C?H functionalization reactions, including aliphatic and aromatic hydroxylation. These transformations are important in a range of biological contexts, including biosynthesis and xenobiotic biodegradation. Much work has been carried out on the mechanism of aliphatic hydroxylation, implicating hydrogen atom abstraction, but aromatic hydroxylation is postulated to proceed differently. One mechanism invokes as the key intermediate an arene oxide (and/or its oxepin tautomer). Conclusive isolation of this intermediate has remained elusive and, currently, direct formation of phenols from a Meisenheimer intermediate is believed to be favored. We report here the identification of a P450 [P450cam (CYP101A1) and P450cin (CYP176A1)]‐generated arene oxide as a product of in vitro oxidation of tert‐butylbenzene. Computations (CBS‐QB3) predict that the arene oxide and oxepin have similar stabilities to other arene oxides/oxepins implicated (but not detected) in P450‐mediated transformations, suggesting that arene oxides can be unstable terminal products of P450‐catalyzed aromatic oxidation that can explain the origin of some observed metabolites. 相似文献
6.
7.
Ion Grosu Lo?c Toupet Gerard Plé Sorin Mager Eugen Mesaros Andreea Varga Elena Bogdan 《Monatshefte für Chemie / Chemical Monthly》2000,54(5):277-286
The synthesis and stereochemistry of new dibrominated spiro-1,3-dioxane derivatives are reported. Investigations by means
of NMR methods and single crystal X-ray diffraction for two compounds revealed the high regio- and diastereoselectivity of
the bromination reaction of some new spiro-1,3-dioxanes and the asymmetric induction of the chiral carbon atom located in
the spiro skeleton. 相似文献
8.
Giuliana Biagi Irene Giorgi Oreste Livi Clementina Manera Valerio Scartoni 《Journal of heterocyclic chemistry》1999,36(5):1195-1198
Some new 1,2,3-triazolo[4,5-e]-1,2,4-triazolo[3, 4 -c]pyrimidmes were prepared starting from the corresponding 1,2,3-triazolo[4,5-d]pyrimidines via the formation of the 1,2,4-triazole ring. Thus suitable hydrazino derivatives 6 were condensed with triethyl orthoformate, triethyl orthoacetate and triethyl orthobenzoate to give the expected tricyclic derivatives 7 , 8 and 9 . Intramolecular cyclization of the ethoxycarbonylhydrazino derivatives 10 gave the tricyclic compounds 11 bearing an hydroxyl group in the 3 position. The v-triazolo-s-triazolopyrimidine derivatives were tested towards the A1 and A2A adenosine receptors in binding assays, but they did not show any receptor affinity. 相似文献
9.
Clementina M. M. Santos Artur M. S. Silva Jos A. S. Cavaleiro Tams Patonay Albert Lvai 《Journal of heterocyclic chemistry》2006,43(5):1319-1326
The epoxidation of 2‐styrylchromones 2a‐h using Jacobsen's Mn(III)[salen] complex 1 as catalyst is reported for the first time. Several studies were performed using both hydrogen peroxide and iodosylbenzene as oxidants, in order to obtain the α,β‐epoxy‐2‐styrylchromones 3a‐h regioselectively. Due to the low reactivity of the substrates and the highly unstable character of the formed epoxides, reactions should be interrupted at lower conversions to obtain acceptable yields, especially when hydrogen peroxide is used. 相似文献
10.
K. Fujita A. Mesaros M.J. Lawler S. Sachdev J. Zaanen H. Eisaki S. Uchida E.-A. Kim J.C. Davis 《Physica B: Condensed Matter》2012,407(11):1859-1863
We use spectroscopic imaging scanning tunneling microscopy (SI-STM) to visualize the spatial symmetries of the electronic states that occur at the pseudogap energy scale in underdoped cuprates. We find evidence for the local intra-unit-cell electronic nematicity—by which we mean the disordered breaking of C4v symmetry within each CuO2 unit cell [1]. We also find that the coexisting incommensurate (smectic) electronic modulations couple to the intra-unit-cell nematicity through their 2π topological defects [2]. 相似文献