Search results for "Cytotoxic"
showing 10 items of 1673 documents
Steroidal saponins from Raphia vinifera and their cytotoxic activity
2020
Abstract Phytochemical analysis of the fruits of Raphia vinifera led to the isolation of four new steroidal saponins (1–4), along with six known secondary metabolites (6–10). The structures of the isolated compounds were determined based on the analyses of NMR and mass spectrometric data, and chemical degradation reactions. Among the compounds tested, 1 and 4 showed the most promising cytotoxic activity against the drug-sensitive CCRF-CEM leukemia cell lines, with IC50 values of 3.55 µM and 7.14 µM, respectively.
Design, synthesis, and SAR analysis of cytotoxic sinapyl alcohol derivatives.
2005
Five series totalling 51 of sinapyl alcohol derivatives were designed and synthesized. Their cytotoxicity analyses were performed oil six human tumor cell lines Such as PC-3. CNE, KB, A549, BEL-7404, and HeLa. Certain sinapyl alcohol derivatives showed significant cytotoxic activities. Compound 14d exhibited especially potent cytotoxicity against the BEL-7404 cell line with an IC50 value of 0.7 mu M, which showed more cytotoxic activity than the positive control, cisplatin. The structure-cytotoxicity relationships were discussed and the CoMFA analysis was performed using the cytotoxic data against HeLa cells as a template. (c) 2005 Elsevier Ltd. All rights reserved.
Inhibitors of inducible NO synthase expression: total synthesis of (S)-curvularin and its ring homologues.
2008
(S)-Curvularin and its 13-, 14-, and 16-membered lactone homologues were synthesized through a uniform strategy in which a Kochi oxidative decarboxylation and ring-closing metathesis reactions constitute the key processes. In the evaluation of the anti-inflammatory effects of the synthesized compounds in assays using cells stably transfected with a human iNOS promoter-luciferase reporter gene construct, the 14- and 16-membered homologues showed a slightly higher inhibitory effect towards iNOS promoter activity than curvularin itself. However, the larger ring homologues also exhibited higher cytotoxicity, manifest in downregulated eNOS promoter activity. In contrast, the di-O-acetyl and 4-ch…
In vitro leishmanicidal activity of pyrazole-containing polyamine macrocycles which inhibit the Fe-SOD enzyme of Leishmania infantum and Leishmania b…
2014
The in vitro leishmanicidal activity and cytotoxicity of pyrazole-containing macrocyclic polyamines 1-4 was assayed on Leishmania infantum and Leishmania braziliensis species. Compounds 1-4 were more active and less toxic than glucantime and both infection rates and ultrastructural alterations confirmed that 1 and 2 were highly leishmanicidal and induced extensive parasite cell damage. Modifications in the excretion products of parasites treated with 1-3 were also consistent with substantial cytoplasm alterations. Compound 2 was highlighted as a potent inhibitor of Fe-SOD in both species, whereas its effect on human CuZn-SOD was poor. Molecular modelling suggested that 2 could deactivate Fe…
Polyketide Derivatives from Mangrove Derived Endophytic Fungus Pseudopestalotiopsis theae
2020
Chemical investigation of secondary metabolites from the endophytic fungus Pseudopestalotiopsis theae led to the isolation of eighteen new polyketide derivatives, pestalotheols I&ndash
Dopaminergic isoquinolines with hexahydrocyclopenta[ ij ]-isoquinolines as D 2 -like selective ligands
2016
Dopamine receptors (DR) ligands are potential drug candidates for treating neurological disorders including schizophrenia or Parkinson's disease. Three series of isoquinolines: (E)-1-styryl-1,2,3,4-tetrahydroisoquinolines (series 1), 7-phenyl-1,2,3,7,8,8a-hexahydrocyclopenta[ij]-IQs (HCPIQs) (series 2) and (E)-1-(prop-1-en-1-yl)-1,2,3,4- tetrahydroisoquinolines (series 3), were prepared to determine their affinity for both D1and D2-like DR. The effect of different substituents on the nitrogen atom (methyl or allyl), the dioxygenated function (methoxyl or catechol), the substituent at the β-position of the THIQ skeleton, and the presence or absence of the cyclopentane motif, were studied. We…
Triphenylphosphane Pt(II) complexes containing biologically active natural polyphenols: Synthesis, crystal structure, molecular modeling and cytotoxi…
2016
Platinum complexes bearing phosphane ligands in cis configuration with deprotonated flavonoids (3-hydroxyflavone, quercetin) and deprotonated ethyl gallate were synthesized starting from cis-[PtCl2(PPh3)(2)]. In all cases, O,O' chelate structures were obtained. While quercetin and ethyl gallate complexes are quite stable in solution, the 3-hydroxyflavonate complex undergoes a slow aerobic photodegradation in solution with formation of salicylic and benzoic acids. The X-ray diffraction structures of quercetin and ethyl gallate complexes are reported. Cell cycle studies (in the dark) of the complexes in two human cell lines revealed that the cytotoxic activity of the complex bearing 3-hydroxy…
Double-Network-Structured Graphene Oxide-Containing Nanogels as Photothermal Agents for the Treatment of Colorectal Cancer.
2017
Here, we reported the production of hyaluronic acid/polyaspartamide-based double-network nanogels for the potential treatment of colorectal carcinoma. Graphene oxide, thanks to the huge aromatic surface area, allows to easily load high amount of irinotecan (33.0% w/w) and confers to the system hyperthermic properties when irradiated with a near-infrared (NIR) laser beam. We demonstrate that the release of antitumor drug is influenced both by the pH of the external medium and the NIR irradiation process. In vitro biological studies, conducted on human colon cancer cells (HCT 116), revealed that nanogels are uptaken by the cancer cells and, in the presence of the antitumor drug, can produce a…
2NH and 3OH are crucial structural requirements in sphingomyelin for sticholysin II binding and pore formation in bilayer membranes.
2013
AbstractSticholysin II (StnII) is a pore-forming toxin from the sea anemone Stichodactyla heliantus which belongs to the large actinoporin family. The toxin binds to sphingomyelin (SM) containing membranes, and shows high binding specificity for this lipid. In this study, we have examined the role of the hydrogen bonding groups of the SM long-chain base (i.e., the 2NH and the 3OH) for StnII recognition. We prepared methylated SM-analogs which had reduced hydrogen bonding capability from 2NH and 3OH. Both surface plasmon resonance experiments, and isothermal titration calorimetry measurements indicated that StnII failed to bind to bilayers containing methylated SM-analogs, whereas clear bind…
Pore formation by Vibrio cholerae cytolysin follows the same archetypical mode as beta-barrel toxins from gram-positive organisms.
2009
Vibrio cholerae cytolysin (VCC) forms SDS-stable heptameric beta-barrel transmembrane pores in mammalian cell membranes. In contrast to structurally related pore formers of gram-positive organisms, no oligomeric prepore stage of assembly has been detected to date. In the present study, disulfide bonds were engineered to tie the pore-forming amino acid sequence to adjacent domains. In their nonreduced form, mutants were able to bind to rabbit erythrocytes and to native erythrocyte membranes suspended in PBS solution and form SDS-labile oligomers. These remained nonfunctional and represented the long-sought VCC prepores. Disulfide bond reduction in these oligomers released the pore-forming se…