Search results for "Phenanthrenes"
showing 10 items of 48 documents
Molybdenum Pentachloride Mediated Synthesis of Spirocyclic Compounds by Intramolecular Oxidative Coupling
2015
The oxidative treatment of (m)ethyl 2-aryl cinnamates equipped with methoxy groups in position 4 of the phenyl moiety promote the formation of cyclohexadienone substructures. This dealkylative oxidative C–C coupling gives access to spirocyclic compounds and avoids the construction of the corresponding phenanthrenes. Furthermore, the transformation can be expanded to other spirocyclic systems.
Retene causes multifunctional transcriptomic changes in the heart of rainbow trout (Oncorhynchus mykiss) embryos
2015
Fish are particularly sensitive to aryl hydrocarbon receptor (AhR)-mediated developmental toxicity. The molecular mechanisms behind these adverse effects have remained largely unresolved in salmonids, and for AhR-agonistic polycyclic aromatic hydrocarbons (PAHs). This study explored the cardiac transcriptome of rainbow trout (Oncorhynchus mykiss) eleuteroembryos exposed to retene, an AhR-agonistic PAH. The embryos were exposed to retene (nominal concentration 32 μg/L) and control, their hearts were collected before, at and after the onset of the visible signs of developmental toxicity, and transcriptomic changes were studied by microarray analysis. Retene up- or down-regulated 122 genes. Th…
Cryptotanshinone deregulates unfolded protein response and eukaryotic initiation factor signaling in acute lymphoblastic leukemia cells.
2015
Abstract Background: Unfolded protein responses (UPR) determine cell fate and are recognized as anticancer targets. In a previous research, we reported that cryptotanshinone (CPT) exerted cytotoxic effects toward acute lymphoblastic leukemia cells through mitochondria-mediated apoptosis. Purpose: In the present study, we further investigated the role of UPR in CPT-induced cytotoxicity on acute lymphoblastic leukemia cells by applying tools of pharmacogenomics and bioinformatics. Methods: Gene expression profiling was performed by mRNA microarray hybridization. Potential transcription factor binding motifs were identified in the promoter regions of the deregulated genes by Cistrome software.…
External and internal exposure to polycyclic aromatic hydrocarbons (PAH) among workers in the production of fire-proof materials – Proposal of a biol…
2006
In 1999, we introduced the German polycyclic aromatic hydrocarbons (PAH) study. The study was designed as a nation-wide investigation on workers exposed to PAH. One aim of the study was to establish biological monitoring guidance values (BMGVs) for different branches. Here, we report on the production of fire-proof materials. This branch of industry is typically confronted with high exposure to PAH and with PAH-induced occupational (cancer) diseases. One hundred and thirty-five employees participated in the course of seven sampling dates in four different plants in Germany. External exposure was determined by personal air monitoring of the 16 EPA-PAH. Human biological monitoring was accompl…
A New Phenanthrene Glycoside and Other Constituents from Dioscorea opposita
2005
Phytochemical investigation of the rhizome of Dioscorea opposita has led to the isolation of a new phenanthrene glycoside, 3,4,6-trihydroxyphenanthrene-3-O-beta-D-glucopyranoside (1), and five known compounds, soyacerebroside I (2), adenosine (3), beta-sitosterol (4), palmitic acid (5) and palmitoyloleoylphosphatidylcholine (6). Their structures were determined by spectroscopic methods, including 1D- and 2D-NMR. Compounds 1-6 exhibited no antifungal activity against the human pathogenic yeasts Candida albicans, C. glabrata and C. tropicalis.
Reactive oxygen species (ROS) generation inhibited by aporphine and phenanthrene alkaloids semi-synthesized from natural boldine.
2004
Four phenanthrene and one aporphine alkaloids semi-synthesized from boldine were evaluated for their inhibitory effect on reactive oxygen species (ROS) generation. ROS generation by neutrophils stimulated with N-formyl-methionyl-leucyl-phenylalanine was inhibited in a concentration dependent manner. Alkaloids exerted similar inhibitory effect in the hypoxanthine-xanthine oxidase system than in stimulated neutrophils, which could be attributed to a direct ROS scavenging activity. None of the alkaloids assayed had any effect on xanthine oxidase activity. Therefore the synthesized alkaloids might constitute an alternative therapy in inflammation disorders in which ROS generation is involved.
Studies of the binding of diolepoxide metabolites of polycyclic aromatic hydrocarbons to DNA using electrofluorescence polarization spectroscopy
1996
In the electrofluorescence method, a solution of DNA with covalently bound polycyclic hydrocarbons is placed in an electric field, and changes in the intensity of polarized fluorescence are observed. Under the correct conditions, these charges can be used to determine a value for the angle psi between the long axis of the hydrocarbon molecule and the axis of the DNA helix. For DNA or poly(dA-dT) treated with each stereoisomer of anti-benzo[c]phenanthrene diolepoxide, psi ranged from 55 degrees to 61 degrees, consistent with a mixture of quasi-intercalated adenine adducts and externally bound guanine adducts. Similar results were obtained with another set of 'fjord-region' diolepoxides, deri…
Malignant transformation of the liver tumour precursor cell line OC/CDE 22 by the four stereoisomeric fjord region 3,4-dihydrodiol 1,2-epoxides of be…
1995
In previous work we established the rat liver oval cell line OC/CDE 22 in order to study in vitro mechanisms of liver cell transformation. We have now exposed OC/CDE 22 cells to each of the four optically active fjord region dihydrodiol epoxides of benzo[c]phenanthrene to investigate their capacity for malignant transformation of liver cells. All four configurational isomers, which are among the most potent carcinogenic metabolites of polycyclic aromatic hydrocarbons tested in murine tumour models, malignantly transform OC/CDE 22 cells at a 2 microM dose level, resulting in a similar colony-forming efficiency in soft agar. Inoculation of the transformed cells into newborn syngeneic rats pro…
Role of the Ha-ras gene in the malignant transformation of rat liver oval cells.
1997
We have shown that the oval cell line OCICDE 22 can be transformed by the highly carcinogenic fiord-region diol epoxides of benzo[c]phenanthrene. Mutational activation of the ras proto-oncogene family has been proposed to be a critical event in the formation of tumors induced by polycyclic aromatic hydrocarbons. Therefore, we investigated whether in the earlier transformed OCICDE 22 cells any point mutations were detected in the ras proto-oncogene. The results indicate that the malignant transformation of OCICDE 22 cells by the 4 stereoisomeric benzo[c]phenan-threne diol epoxides in vitro is independent of activation of the Ha-ras proto-oncogene. In addition, Northern and Western blot analy…
Covalent DNA adducts formed by benzo[c]chrysene in mouse epidermis and by benzo[c]chrysene fjord-region diol epoxides reacted with DNA and polynucleo…
1997
The metabolic activation in mouse skin of benzo[c]chrysene (B[c]C), a weakly carcinogenic polycyclic aromatic hydrocarbon (PAH) present in coal tar and crude oil, was investigated. Male Parkes mice were treated topically with 0.5 mumol of B[c]C, and DNA was isolated from the treated areas of skin at various times after treatment and analyzed by 32P-postlabeling. Seven adduct spots were detected, at a maximum level of 0.89 fmol of adducts/microgram of DNA. Four B[c]C-DNA adducts persisted in skin for at least 3 weeks. Treatment of mice with 0.5 mumol of the optically pure putative proximate carcinogens (+)- and (-)-trans-benzo[c]chrysene-9,10-dihydrodiols [(+)- and (-)-B[c]C-diols] led to th…