34 research outputs found
Design and Synthesis of Novel Hyperforin Analogues - Fascinating skeletal rearrangements of polycyclic polyprenylated acylphloroglucinols core
Seismic analysis of buildings with masts on the roof [Erdbebeneinwirkungen von Gebäuden mit aufgesetzten Masten]
Synthesis, spectroscopic, and structural characterization of the first aqueous cobalt(II)-citrate complex: toward a potentially bioavailable form of cobalt in biologically relevant fluids
Citric acid represents a class of carboxylic acids present in biological fluids and playing key roles in biochemical processes in bacteria and humans. Its ability to promote diverse coordination chemistries in aqueous media, in the presence of metal ions known to act as trace elements in human metabolism, earmarks its involvement in a number of physiological functions. Cobalt is known to be a central element of metabolically important biomolecules, such as B 12 , and therefore its biospeciation in biological fluids constitutes a theme worthy of chemical and biological perusal. In an effort to unravel the aqueous chemistry of cobalt in the presence of a physiologically relevant ligand, citrate, the first aqueous, soluble, mononuclear complex has been synthesized and isolated from reaction mixtures containing Co(II) and citrate in a 1 :2 molar ratio at pH∼8. The crystalline compound (NH 4 ) 4 [Co(C 6 H 5 O 7 ) 2 ] ( 1 ) has been characterized spectroscopically (UV/vis, EPR) and crystallographically. Its X-ray structure consists of a distorted octahedral anion with two citrate ligands fulfilling the coordination requirements of the Co(II) ion. The magnetic susceptibility measurements of 1 in the range from 6 to 295 K are consistent with a high-spin complex containing Co(II) with a ground state S =3/2. Corroborating this result is the EPR spectrum of 1 , which shows a signal consistent with the presence of a Co(II) system. The spectroscopic and structural properties of the complex signify its potential biological relevance and participation in speciation patterns arising under conditions consistent with those employed for its synthesis and isolation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42326/1/775-5-4-469_00050469.pd
Synthesis and Spectroscopic and Structural Studies of a New Cadmium(II)−Citrate Aqueous Complex. Potential Relevance to Cadmium(II)−Citrate Speciation and Links to Cadmium Toxicity
Synthesis, spectroscopic, and structural characterization of the first aqueous cobalt(II)-citrate complex: toward a potentially bioavailable form of cobalt in biologically relevant fluids
Synthesis, pH-Dependent Structural Characterization, and Solution Behavior of Aqueous Aluminum and Gallium Citrate Complexes
Aminonaphthalene 2‑Cyanoacrylate (ANCA) Probes Fluorescently Discriminate between Amyloid‑β and Prion Plaques in Brain
A major challenge for diagnosing and monitoring the progression
of amyloid-based diseases is the capability to distinguish between
amyloid deposits that are associated with related, but distinctly
different, diseases. Here, we demonstrate that aminonaphthalenyl 2-cyanoacrylate-based
probes can fluorescently discriminate between different types of amyloid
deposits in brain. The discriminating capability of these molecular
rotors is due to the stabilization of the ground versus excited states
of these probes as a function of the polarity of their microenvironment
(i.e., within the binding pocket on the amyloid). This property makes
it possible, for the first time, to estimate the inherent static relative
permittivity (ε<sub>0</sub>) of the binding pocket of each amyloid
within tissue. The capability to selectively follow the deposition
of specific amyloids in tissue may provide important information for
therapeutic development that is not readily accessible from currently
available technology