The reactions of auranofin and three pseudohalide derivatives with bovine serum albumin were explored by ESI-Q-TOF mass spectrometry; a detailed molecular description of the resulting adducts is achieved revealing even subtle differences in reactivity within this series of gold(I) complexes. Our study shows that this kind of investigative approach, formerly applied to the interactions of metal-based drugs with small model proteins of MW 10-15 kDa, e.g., cytochrome c and lysozyme, may now be extended with success to far larger proteins such as serum albumin (MW 66 kDa).
Ultra-high-performance liquid chromatography coupled with high-resolution quadrupole-time of flight mass spectrometry with both negative and positive ionization was used for comprehensively investigating the phenolic and polyphenolic compounds in berries from three spontaneous or cultivated Vaccinium species (i.e., Vaccinium myrtillus, Vaccinium uliginosum subsp. gaultherioides, and Vaccinium corymbosum). More than 200 analytes, among phenolic and polyphenolic compounds belonging to the classes of anthocyanins, monomeric and oligomeric flavonols, flavanols, dihydrochalcones, phenolic acids, together with other polyphenolic compounds of mixed structural characteristics, were identified. Some of the polyphenols herein investigated, such as anthocyanidin glucuronides and malvidin-feruloyl-hexosides in V. myrtillus, or anthocyanindin aldopentosides and coumaroyl-hexosides in V. uliginosum subsp. gaultherioides and a large number of proanthocyanidins with high molecular weight in all species, were described for the first time in these berries. Principal component analysis applied on original LC-TOF data, acquired in survey scan mode, successfully discriminated the three Vaccinium berry species investigated, on the basis of their polyphenolic composition, underlying one more time the fundamental role of mass spectrometry for food characterization.
The silver(I) N‐heterocyclic carbene (NHC) complex bis(1‐(anthracen‐9‐ylmethyl)‐3‐ethylimidazol‐2‐ylidene) silver chloride ([Ag(EIA)2]Cl), bearing two anthracenyl fluorescent probes, has been synthesized and characterized. [Ag(EIA)2]Cl is stable in organic solvents and under physiological conditions, and shows potent cytotoxic effects in vitro toward human SH‐SY5Y neuroblastoma cells. The interactions of [Ag(EIA)2]Cl with a few model biological targets have been studied as well as its ability to be internalized in cells. The in vitro anticancer activity is apparently related to the level of drug internalization. Notably, [Ag(EIA)2]Cl does not react with a few model proteins, but is capable of binding the C‐terminal dodecapeptide of thioredoxin reductase hTrxR(488–499) and to strongly inhibit the activity of this enzyme. Binding occurs through an unconventional process leading to covalent binding of one or two carbene ligands to the C‐terminal dodecapeptide with concomitant release of the silver cation. To the best of our knowledge, this mode of interaction is reported here for the first time for Ag(NHC)2 complexes.
c.3435CC patients require higher clozapine doses to achieve the same plasma concentrations as CT or TT patients, and ABCB1 genotyping should be considered as a novel strategy that should improve drug use.
Seven quick, easy, cheap, effective, rugged and safe (QuEChERS)-based procedures, differing in both the extraction and clean-up steps, were investigated for the recovery of bentazone (BTZ), atrazine (ATZ), carbamazepine (CBZ), phenytoin (PNT) and its metabolite 5-(p-hydroxyphenyl-),5-phenylhydantoin (HPPH) from soil. Target analytes were chosen for their extensive use and/or occurrence in soil, as well as for their medium-high polarity characteristics (log K OW values in the range 0.88-2.80), which have been reported as a critical parameter for the recovery from soil with QuEChERS approaches. Liquid chromatography coupled with UV and pulsed amperometric (PA) detection at a glassy carbon electrode was used as instrumental technique. The recovery data obtained within each tested procedure were discussed for each compound investigated, highlighting different behaviour depending on the specific physicochemical characteristics of the analytes. The optimized QuEChERS conditions consisted of the extraction of analytes with CH3CN:H2O 70:30, 5 % CH3COOH, followed by a dispersive solid-phase extraction (d-SPE) clean-up step with C18 sorbent. This method, in which water is directly added to the soil together with acetonitrile and salts, allowed the rehydration step to be avoided, which can be as long as 30 min. Matrix effects were evaluated for both the detection techniques at different concentration levels, and they were below 24 % for both the detection technique used. The recoveries were evaluated at three concentration levels by a matrix-matched calibration and were in the ranges of 83-113 % (relative standard deviations (RSD) ≤ 14 %) and 88-109 % (RSD ≤ 11 %) for UV and PA detection, respectively, highlighting very good performances of the method, even for the more polar analytes. Method detection limits ranged from 4 μg/kg (BTZ) to 493 μg/kg (PNT) and from 4 μg/kg (HPPH) to 11 μg/kg (BTZ) for UV and PA detection, respectively. The method was finally compared with a microwave-assisted extraction procedure which provided less satisfactory extraction performances than the optimized QuEChERS procedure.
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