Anionic
Dotaz
Zobrazit nápovědu
- MeSH
- finanční podpora výzkumu jako téma MeSH
- fosfatidylglyceroly fyziologie chemie metabolismus MeSH
- fotosyntéza fyziologie genetika MeSH
- geny genetika MeSH
- kardiolipiny fyziologie chemie metabolismus MeSH
- mitochondrie metabolismus MeSH
- mutace MeSH
- stárnutí buněk fyziologie MeSH
- Publikační typ
- přehledy MeSH
The literature reports on cationic and anionic phthalocyanines (Pcs) for photodynamic therapy suggest systematically significant differences in activity. In this work, ten different zinc(II) Pcs with carboxylate functions or quaternary nitrogens (hydrophilic anionic, hydrophilic cationic, amphiphilic anionic, and amphiphilic cationic) were investigated, with the aim of revealing reasons for such differences. In vitro assays on HeLa, MCF-7, and HCT-116 cells confirmed higher photoactivity for cationic Pcs (EC50 ∼ 3-50 nM) than for anionic Pcs (EC50 ∼ 0.3-10 μM), the latter being additionally significantly more active in serum-free medium. The environmental pH, binding to serum proteins, interaction with biomembranes, differences in subcellular localization, and relocalization after irradiation were found to be the main factors contributing to the generally lower photoactivity of anionic Pcs than that of the cationic derivatives. This result is not limited only to the presented derivatives and should be considered in the design of novel photosensitizers.
- MeSH
- fosfatidylcholiny chemie metabolismus MeSH
- fotochemoterapie MeSH
- fotosenzibilizující látky chemická syntéza metabolismus farmakologie účinky záření MeSH
- indoly chemická syntéza metabolismus farmakologie účinky záření MeSH
- lidé MeSH
- liposomy chemie metabolismus MeSH
- molekulární struktura MeSH
- nádorové buněčné linie MeSH
- protinádorové látky chemická syntéza metabolismus farmakologie účinky záření MeSH
- screeningové testy protinádorových léčiv MeSH
- sérový albumin hovězí metabolismus MeSH
- singletový kyslík metabolismus MeSH
- světlo MeSH
- zinek chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The continuous expansion of research in the field of stable carboranes and their wide potential in the drug design require carrying out fundamental studies regarding their chiral separations. Although supercritical fluid chromatography (SFC) is a viable technique for fast enantioseparations, no investigation concerning boron cluster compounds has been done yet. We aimed at the development of a straightforward method enabling chiral separations of racemic mixtures of anionic cluster carboranes and metallacarboranes that represent an analytical challenge. The fast gradient screening testing nine polysaccharide-based columns was used. The key parameters affecting the selectivity were the type of chiral selector, the type of alcohol, and the base in cosolvent. Moreover, the addition of acetonitrile or water to the cosolvent was identified as an effective tool for decreasing the analysis time while preserving the resolution. After the optimization, the chiral separations of 19 out of 20 selected compounds were achieved in less than 10 min. These results demonstrate the clear advantage of SFC over chiral separations using HPLC in terms of both analysis time and structural variety of successfully separated compounds.
We present a method for finely adjustable electroosmotic flow (EOF) velocity in cathodic direction for the optimization of separations in capillary electrophoresis. To this end, we use surface modification of the separation fused silica capillary by the covalently attached copolymer of acrylamide (AM) and 2-acrylamido-2-methyl-1-propanesulfonate (AMPS), that is, poly(AM-co-AMPS) or PAMAMPS. Coatings were formed by the in-capillary polymerization of a mixture of the neutral AM and anionic AMPS monomers premixed in various ratios in order to control the charge density of the copolymer. EOF mobility varies in the 0 to ∼40 × 10-9 m2 V-1 s-1 interval for PAMAMPS coatings ranging from 0 to 60 mol.% of charged AMPS monomer. For EOF in PAMAMPS-treated capillaries, we observed (i) a negligible dependence on pH in the 2-10 interval, (ii) a minor variance among background electrolytes (BGEs) in function of their components and (iii) its standard decrease with increasing ionic strength of the BGE. Interest in variable cathodic EOF was demonstrated by the amelioration of separation of two kinds of isomeric anionic analytes, that is, monosaccharides phosphates and helquat enantiomers, in counter-EOF mode.
The most common type of aflatoxin (AFT) found in nature is aflatoxin B1 (AFB1). This micotoxin is extremely hepatotoxic and carcinogenic to mammals, with acute and chronic effects. It is believed that this could be related to the capacity of AFB1 and its metabolites in inhibiting the enzyme acetylcholinesterase (AChE). In a previous work, we performed an inedited theoretical investigation on the binding modes of these molecules on the peripheral anionic site (PAS) of human AChE (HssAChE), revealing that the metabolites can also bind in the PAS in the same way as AFB1. Here, we investigated the binding modes of these compounds on the catalytic anionic site (CAS) of HssAChE to compare the affinity of the metabolites for both binding sites as well as verify which is the preferential one. Our results corroborated with experimental studies pointing to AFB1 and its metabolites as mixed-type inhibitors, and pointed to the residues relevant for the stabilization of these compounds on the CAS of HssAChE.
- MeSH
- acetylcholinesterasa chemie metabolismus MeSH
- aflatoxin B1 chemie metabolismus MeSH
- cholinesterasové inhibitory chemie metabolismus MeSH
- hydrofobní a hydrofilní interakce MeSH
- katalytická doména MeSH
- lidé MeSH
- molekulární modely * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
