Search results for "Activity"

Struktur-Wirkungs-Beziehungen bei Analeptica vom Typ des Nicethamids, 3. Mitt. Synthese von Analogen des 6-Methyl-nicethamids

1975

Als potentiell analeptisch wirksame Substanzen mit partiell fixierter funktioneller Gruppe werden strukturanaloge Amide, Imide und Lactame des 2-Methyl-nicethamids synthetisiert. Synthesis of 2-Methyl-Nicethamide Analogues. As potentially analeptically active substances with partially fixed functional groups, structural analogues of 2-methyl-nicethamide, in the form of amides, imides and lactams, are synthesized.

Light Regulation of the Thylakoid LHCII Protein Phosphorylation at the Substrate Level

1998

The distribution of light energy between the two photosystems as well as the light-induced turnover of PSII proteins are regulated by the reversible phosphorylation of LHCII and the PSII-core proteins. The thylakoid protein kinase(s) is activated by a signal transduction system involving the interaction of reduced plastoquinone with the quinol oxidation site of the cytochrome bf complex [1]. Phosphorylation of the mobile pool of LHCII induces dissociation of this antenna from PSII and allows its interaction with the PSI in the stroma exposed membranes (state transition)[21. Dephosphorylation of LHCII by a membrane -bound phosphatase appears to be regulated by a cyclophilinlike protein locat…

Synthesis, Structure, and Reactivity of the First Enantiomerically Pure Ortho-Metalated Rhodium(II) Dimer

1999

Monomere und polymere Succinimidoester von ω-Methacryloylaminosäuren, ihre Darstellung und ihre Reaktion mit Aminen

1978

Mit der in dieser Arbeit beschriebenen Synthese von ω-Methacryloylaminosaure-succinimidoestern (1) wurden Monomere erhalten, die leicht mit Methacrylamid copolymerisiert werden konnten. Die entstandenen Copolymeren, die als Trager fur Enzyme und Pharmaka verwendet werden konnen, tragen die selektiv mit Aminen reagierende Succinimidoester-Gruppe an einem “Spacerarm”. Die Reaktionsfahigkeit der neuen Monomeren gegenuber verschiedenen Aminen wurde untersucht. The synthesis of succinimido esters of ω-methacryloylaminocarboxylic acids affords monomers which can easily be copolymerized with methacrylamide. The resulting copolymers have a succinimido ester group fixed on a “spacer arm”, which reac…

Antibakterielle Wirkstoffe, 6. Mitt.1) 2,4-Unsymmetrisch dialkylierte Pyrimido[1,2-a]benzimidazole

1982

Durch Kondensation von 2-Aminobenzimidazol (1) mit 2,4-Hexandion (2a) entsteht das Isomerenpaar 3a/3b, mit 6-Methyl-2,4-heptandion (2b) das Isomerengemisch 3c/3d, wahrend mit 1-Phenyl-2,4-pentandion (2c) die Isomere 3e und 3f gebildet werden. Die Trennung der Isomere ist durch Saulenchromatographie, die Strukturfestlegung auf spektroskopischem Wege, moglich. 2-Imino-2H-s-triazino[2,1-b]benzoxazol weist antibakterielle Wirksamkeit auf. Antibacterial Drugs, VI: 2,4-Unsymmetrically Dialkylated Pyrimido[1,2-α]benzimidazoles Condensation of 2-aminobenzimidazole (1) with 2,4-hexanedione (2a) leads to the pair of isomers 3a/3b. Condensation with 6-methyl-2,4-heptanedione (2b) yields the isomers 3c…

A quantum chemical topological analysis of the c-c bond formation in organic reactions involving cationic species

2014

ELF topological analysis of the ionic Diels-Alder (I-DA) reaction between the N,N-dimethyliminium cation and cyclopentadiene (Cp) has been performed in order to characterise the C-C single bond formation. The C-C bond formation begins in the short range of 2.00-1.96 Åvia a C-to-C pseudoradical coupling between the most electrophilic center of the iminium cation and one of the two most nucleophilic centers of Cp. The electron density of the pseudoradical center generated at the most electrophilic carbon of the iminium cation comes mainly from the global charge transfer which takes place along the reaction. Analysis of the global reactivity indices indicates that the very high electrophilic c…

ChemInform Abstract: The Chemistry of Unsaturated Nitrogen-Heterocyclic Compounds Containing Carbonyl Groups

2010

Publisher Summary Most hydroxy-substituted azaheteroaromatic compounds exist predominately in the NH/carbonyl tautomeric form, and these compounds have been widely discussed. This chapter provides an overview of azaheteroaromatic compounds and I-azetin-4-ones—these are those azaheterocycles that contain in the ring at least one carbonyl group and one or two nitrogen atoms in the form of C=N or N=N bonds. Many of these compounds are unstable but their importance as reactive intermediates is established, and many of them could be used as synthons in the preparation of pharmacologically active compounds. The chapter describes the free existence of I-azetin-4-one and the nucleophilic substituti…

The Chemistry of Unsaturated Nitrogen–Heterocyclic Compounds Containing Carbonyl Groups

1993

Publisher Summary Most hydroxy-substituted azaheteroaromatic compounds exist predominately in the NH/carbonyl tautomeric form, and these compounds have been widely discussed. This chapter provides an overview of azaheteroaromatic compounds and I-azetin-4-ones—these are those azaheterocycles that contain in the ring at least one carbonyl group and one or two nitrogen atoms in the form of C=N or N=N bonds. Many of these compounds are unstable but their importance as reactive intermediates is established, and many of them could be used as synthons in the preparation of pharmacologically active compounds. The chapter describes the free existence of I-azetin-4-one and the nucleophilic substituti…

Linear free energyortho-correlations in the thiophene series. Part IX . Kinetics of esterification with diazodiphenylmethane of some 3-, 4-, and 5-su…

1981

The rate constants for the esterification of some 3-, 4-, and 5-substituted thiophene-2-carboxylic acids with diazodiphenylmethane in methanol at 25° have been measured. The reactivity of some para- and ortho-substituted benzoic acids has also been determined. Logarithmic kinetic constants for ortho-, meta-, and para-like substituted thiophene-2-carboxylic acids furnish an excellent linear free energy relationship when plotted versus Δpka (β 0.89, r 0.989, C.L. > 99.9%, n 18, i 0.04), thus confirming the peculiar behaviour of five-membered ring derivatives. The correlation with σH values offers an additional proof of the hyper-ortho character of the 2,3-relation in thiophene derivatives. pa…

Electrophilic substitution and cyclization of 2,2′-bis(N-methylindolyl): A simple access to potential protein kinase C inhibitor

1994

A strategy is described for the synthesis of functionalized and cyclized 2,2′-bisindolyl derivatives related to several basic systems of natural products. The starting 2,2′-bis(N-methylindolyl) (8) reacts with a variety of electrophiles and electrophilic dienophiles to furnish the novel, functionalized and cyclized bisindolyl derivatives 9–16. In addition, some reactivity and structural aspects are discussed; an X-ray crystallographic analysis of the 2,2′-bisindolyl 8 provided valuable information for the conformational analyses.