Search results for "Cytotoxicity"
showing 10 items of 865 documents
DNA strand break induction, mutagenicity, and cytotoxicity of the mycotoxins 11-β-hydroxy-7-deoxy-rosenonolactone, rosenonolactone, and trichothecin.
1992
11-β-hydroxy-7-deoxy-rosenonolactone (TSS1), a mycotoxin of the rosenane class, was tested on cytotoxicity, induction of DNA single strand breaks and muta-genicity. Its effects were compared to those of rosenonolactone and trichothecin. TSS1 had stronger antibiotic activity againstEscherichia coli (EC 50: 10μg/mL) than rosenonolactone (EC 50: >200μg/mL) but weaker activity than trichothecin (EC 50: 3μg/mL). The same order of activity was found for the inhibition of yeast fermentation (EC 50 of TSS1: 45μg/mL; EC 50 of rosenonolactone: > 120μg/mL; EC 50 of trichothecin: 3.4μg/mL). In the trypan blue exclusion test using V79 Chinese hamster cells, TSS1 proved to be cytotoxic (EC50: 30μg/mL) at…
Organometallic complexes with biological molecules: V.In vivo cytotoxicity of diorganotin(IV)-amoxicillin derivatives in mitotic chromosomes ofrutilu…
1995
In order to test in vivo cytotoxicity of diorganotin(IV)-amoxicillin (amox) derivatives, mitotic chromosomes of Rutilus rubilio (Pisces, Cyprinidae) have been analyzed using two different chromosome-staining techniques. Results gathered after exposure of fish to the free amox.3H 2 O, R 2 SnClamox.2H 2 O, and R 2 Snamox 2 .2H 2 O (R = methyl, butyl and phenyl ; amox - = 6-[D(-)-β-amino-p-hydroxyphenylacetamido]penicillinate) suggest that methyl derivatives seem to exert a lower cytotoxicity than butyl and phenyl ones and that R 2 Snamox 2 .2H 2 O derivatives are more toxic than R 2 Snclamox.2H 2 O at both 10 -5 and 10 -7 mol dm -3 concentrations. The following structural lesions have been id…
Three New Medicagenic Acid Saponins from Polygala micranthaGuill. & Perr.
2011
Three new medicagenic acid saponins, micranthosides A–C (1–3), were isolated from the roots of Polygala micranthaGuill. & Perr., along with six known presenegenin saponins. Their structures were elucidated on the basis of extensive 1D- and 2D-NMR experiments (1H, 13C, DEPT, COSY, TOCSY, NOESY, HSQC, and HMBC) and mass spectrometry as 3-O-β-D-glucopyranosylmedicagenic acid 28-[O-β-D-galactopyranosyl-(14)-O-β-D-xylopyranosyl-(14)-O-α-L-rhamnopyranosyl-(12)-β-D-fucopyranosyl] ester (1), 3-O-β-D-glucopyranosylmedicagenic acid 28-[O-6-O-acetyl-β-D-galactopyranosyl-(14)-O-β-D-xylopyranosyl-(14)-O-α-L-rhamnopyranosyl-(12)-β-D-fucopyranosyl] ester (2), and 3-O-{O-β-D-glucopyranosyl-(13)-O-[β-D-gluc…
Drivers of topoisomerase II poisoning mimic and complement cytotoxicity in AML cells
2019
Recently approved cancer drugs remain out-of-reach to most patients due to prohibitive costs and only few produce clinically meaningful benefits. An untapped alternative is to enhance the efficacy and safety of existing cancer drugs. We hypothesized that the response to topoisomerase II poisons, a very successful group of cancer drugs, can be improved by considering treatment-associated transcript levels. To this end, we analyzed transcriptomes from Acute Myeloid Leukemia (AML) cell lines treated with the topoisomerase II poison etoposide. Using complementary criteria of co-regulation within networks and of essentiality for cell survival, we identified and functionally confirmed 11 druggabl…
Tumoricidal Activity of Endothelial Cells
2001
The mechanism of NO- and H(2)O(2)-induced tumor cytotoxicity was examined during B16 melanoma (B16M) adhesion to the hepatic sinusoidal endothelium (HSE) in vitro. We used endothelial nitric-oxide synthetase gene disruption and N(G)-nitro-l-arginine methyl ester-induced inhibition of nitric-oxide synthetase activity to study the effect of HSE-derived NO on B16M cell viability. Extracellular H(2)O(2) was removed by exogenous catalase. H(2)O(2) was not cytotoxic in the absence of NO. However, NO-induced tumor cytotoxicity was increased by H(2)O(2) due to the formation of potent oxidants, likely ( small middle dot)OH and (-)OONO radicals, via a trace metal-dependent process. B16M cells culture…
Hydroquinone derivatives from the marine-derived fungus Gliomastix sp.
2017
Eight new hydroquinone derivatives, gliomastins A–D (1–4), 9-O-methylgliomastin C (5), acremonin A 1-O-β-D-glucopyranoside (6), gliomastin E 1-O-β-D-glucopyranoside (7), and 6′-O-acetyl-isohomoarbutin (8), together with seven known analogues were isolated from the marine-derived fungus Gliomastix sp. Their structures were elucidated by extensive spectroscopic analysis including 1D and 2D NMR measurements aided by DFT NMR calculations as well as MS data. TDDFT-ECD and OR calculations were performed to determine the absolute configurations of 1 and the aglycones of 6 and 7. Compound 1 features a novel skeleton, biogenetically derived from a Diels–Alder reaction between derivatives of 11 and 1…
Ophiobolin Sesterterpenoids and Pyrrolidine Alkaloids from the Sponge-Derived Fungus Aspergillus ustus
2011
Chemical examination of the fungus Aspergillus ustus isolated from the Mediterranean sponge Suberites domuncula yielded the five new ophiobolin-type sesterterpenoids 1–5 and the two new pyrrolidine alkaloids 6 and 7, together with the known compound aurantiamine and cerebroside D. The structures of the new compounds were unambiguously elucidated on the basis of extensive spectroscopic-data analysis (1D- and 2D-NMR, MS, and UV) and comparison with literature data. All compounds were evaluated for their cytotoxicity against murine lymphoma cell line L5178Y.
Cytotoxicity of fagaramide derivative and canthin-6-one from Zanthoxylum (Rutaceae) species against multidrug resistant leukemia cells
2019
In our continuous search for cytotoxic compounds from the genus Zanthoxylum, chromatographic separation of the MeOH/CH2Cl2 (1:1) extract of Z. chalybeum yielded one new alkamide; 4-(isoprenyloxy)-3-methoxy-3,4-deoxymethylenedioxyfagaramide (1) and a known one; fagaramide (2). Similarly, from the MeOH/CH2Cl2 (1:1) extract of the stem bark of Z. parachanthum four known compounds; canthin-6-one (3), dihydrochelerythrine (4), lupeol (5) and sesamin (6) were isolated. Characterization of the structures of these compounds was achieved using spectroscopic techniques (NMR and MS). Using resazurin reduction assay 1, 3 and 6 displayed moderate cytotoxicity with IC50 values below 50 μM against the dru…
Squaraine Dyes for Photodynamic Therapy: Mechanism of Cytotoxicity and DNA Damage Induced by Halogenated Squaraine Dyes Plus Light (>600 nm)¶
2004
Halogenated squaraine dyes 1 and 2 possess favorable photophysical and in vitro photobiological properties that make these new class of molecules interesting for photodynamic therapeutic applications. For a better understanding of the mechanism of their photobiological activity, we have analyzed the DNA damage and the cytotoxicity induced by these photosensitizers in mammalian cells and cell-free systems in the presence and absence of various additives and scavengers. Both photoactivated squaraines were found to be similar efficient in inducing single-strand breaks (SSB) in cell-free DNA when compared with the cellular DNA. Superoxide dismutase and catalase did not show any influence. Howev…
New bioactive alkaloids from the marine sponge Stylissa sp.
2012
Abstract Chemical investigation of the Indonesian marine sponge Stylissa species, which was collected at 2008 from Derawan Islands, Berau, NE Kalimantan, Indonesia offered four new brominated alkaloids, including 12-N-methyl stevensine (1), 12-N-methyl-2-debromostevensine (2), 3-debromolatonduine B methyl ester (3), 3-debromolatonduine A (4) together with eight known alkaloids identified as Z-hymenialdisine, Z-debromohymenialdisine, Stevensine, 2-debromostevensine, 3-bromoaldizine, 3,4-dibromopyrrole-2-carbamide, latonduine A, and latonduine B methyl ester (5–12), respectively. The structures of all isolated compounds were unambiguously elucidated based on extensive 1D and 2D NMR spectrosco…