نتایج جستجو برای: pyrrole
تعداد نتایج: 3583 فیلتر نتایج به سال:
The title compound, C19H19NO5, (I), is the product of a domino reaction between cotarnine chloride and acetyl-acetylene catalysed by copper(I) iodide. The mol-ecule of (I) comprises a fused tetra-cyclic system containing two terminal five-membered rings (pyrrole and 1,3-dioxole) and two central six-membered rings (di-hydro-pyridine and benzene). The five-membered 1,3-dioxole ring has an envelop...
We report the synthesis of both macrocyclic and linear derivatives of pyrrole-2,5-diacetic bisamides, and the studies of their anion binding properties, which are further compared with the properties of similar derivatives bearing dipicolinic or isophthalic moieties. The new macrocyclic compound built on pyrrole-2,5-diacetic bisamide was found to be an efficient receptor for H2PO4 and PhCOO , e...
Porphobilinogen deaminase (PBGD) catalyzes the formation of 1-hydroxymethylbilane (HMB), a crucial intermediate in tetrapyrrole biosynthesis, through a step-wise polymerization of four molecules of porphobilinogen (PBG), using a unique dipyrromethane (DPM) cofactor. Structural and biochemical studies have suggested residues with catalytic importance, but their specific role in the mechanism and...
Laboratory cultures of the fungus Plectosphaerella cucumerina obtained from marine sediments collected in Barkley Sound, British Columbia, yielded the novel alkaloids plectosphaeroic acids A (1) to C (3). The alkaloids 1-3 are inhibitors of indoleamine 2,3-dioxygenase (IDO).
Pyrrole and pyrroldine heterocycles are ubiquitous structural features in natural products. Nature’s biosynthetic machinery often synthesizes the pyrrole functionality in these molecules from a saturated pyrrolidine as part of its metabolic degradation pathway. Interestingly, the chemical synthesis of substituted pyrroles is usually more straightforward in comparison to that of the correspondin...
A glucose sensor was developed by electrocopolymerization using pyrroles containing a tris-bipyridine (bpy) osmium complex (Os-py), pyrrole (py), pyrrole propanoic acid (PPA) and glucose oxidase (GOx) to improve the key performance characteristics, such as the sensitivity, selectivity, and long-term stability. Tris-bipyridine osmium pyrrole complexes with four different methylene moieties were ...
Other than triarylamines, which are protonated by strong acids both at their N-atom and aromatic rings, pyrrole its N-substituted derivatives were exclusively the carbon atoms of heteroaromatic rings. Whereas with trifluoromethane sulfonic acid (TFS) stable pyrrolium salts obtained, weaker trifluoroacetic (TFA) oligomers formed. E.g., from N-(tert-butyl)pyrrole a dimeric compound could be unamb...
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