Search results for "lignan"
showing 10 items of 613 documents
Sesquiterpenes from Centaurea aspera
2005
Abstract The aerial parts of two subspecies of Centaurea aspera L. (Asteraceae) yielded the germacranolides 1a – h , 2 , 3 , 4 and 5 , the elemane derivatives 6d and 6f , the lignan matairesinol, the degraded terpene loliolide, and the onopordopicrin–valine dimeric adduct 7 . From these, compounds 1e , 3 and 6d are natural products. The chemical composition of the two subspecies is very similar, a circumstance which does not support a taxonomic subdivision of the species.
6-Prenyloxy-7-methoxycoumarin, a coumarin-hemiterpene ether from Carduus tenuiflorus
1992
Abstract From the acetone extract of Carduus tenuiflorus , a new coumarin-hemiterpene ether was isolated, which was identified as 6-(3,3-dimethylallyloxy)-7-methoxycoumarin. The synthesis of this coumarin and that of its positional isomer 7-(3,3-dimethylallyloxy)-6-methoxycoumarin were carried out from esculetin. Two other coumarins, three lignans and three flavonoids were also isolated.
ChemInform Abstract: Phenolic Glycosides from Phagnalon rupestre
2010
Analysis of the butanol-soluble fraction from the methanolic extract of the aerial parts of Phagnalon rupestre (Asteraceae) has led to the isolation of seven phenolic compounds. Three have been identified on the basis of their NMR spectra as new natural compounds: the lignan 7,7'-bis-(4-hydroxy-3,5-dimethoxyphenyl)-8,8'-dihydroxymethyl-tetrahydrofuran-4-O-beta-glucopyranoside (1), the prenylhydroquinone glycoside 1-O-beta-glucopyranosyl-1,4-dihydroxy-2-(3'-hydroxy-3'-methylbutyl) benzene (2) and the acetophenone glycoside 12-O-beta-glucopyranosyl-9beta,12-dihydroxytremetone (3). The known flavonoids apigenin-7-O-beta-glucoside, luteolin-7-O-beta-glucoside, luteolin-7-O-beta-glucuronide and …
Sesquiterpene lactones, lignans and aromatic esters from Cheirolophus species
1994
Abstract The aerial parts of five Cheirolophus species yielded three new guaianolides, a new lignan and three new aromatic esters, together with other known compounds of the same type.
Voriconazole and squamous cell carcinoma after lung transplantation: A multicenter study
2017
This study evaluated the independent contribution of voriconazole to the development of squamous cell carcinoma (SCC) in lung transplant recipients, by attempting to account for important confounding factors, particularly immunosuppression. This international, multicenter, retrospective, cohort study included adult patients who underwent lung transplantation during 2005-2008. Cox regression analysis was used to assess the effects of voriconazole and other azoles, analyzed as time-dependent variables, on the risk of developing biopsy-confirmed SCC. Nine hundred lung transplant recipients were included. Median follow-up time from transplantation to end of follow-up was 3.51 years. In a Cox re…
pp32/PHAPI determines the apoptosis response of non-small-cell lung cancer
2007
During malignant transformation, cancer cells have to evade cell-intrinsic tumor suppressor mechanisms including apoptosis, thus acquiring a phenotype that is relatively resistant to clinically applied anticancer therapies. Molecular characterization of apoptotic signal transduction defects may help to identify prognostic markers and to develop novel therapeutic strategies. To this end we have undertaken functional analyses of drug-induced apoptosis in human non-small cell-lung cancer (NSCLC) cells. We found that primary drug resistance correlated with defects in apoptosome-dependent caspase activation in vitro. While cytochrome c-induced apoptosome formation was maintained, the subsequent …
An update on the xenograft and mouse models suitable for investigating new therapeutic compounds for the treatment of B-cell malignancies
2008
B-cell malignancies account for over the 90% of all lymphoid neoplasms. The clonal proliferations of B-cells show a high degree of variation in terms of clinical and presenting features, histopathology, immuophenotype, and genetics. Primary tumor samples are useful for examining the characteristics of a patients own tumor, although both primary leukemic cells and cell lines provide an initial step for screening novel compounds for their activity in some hematological malignancies, they should be followed by models in intact animals. In this review, we try to summarize the animal models generated to study B-cell malignancies, in particular, B-cell lymphoma, B-cell CLL and MM that represent t…
New Potential Therapeutic Approach for the Treatment of B-Cell Malignancies Using Chlorambucil/Hydroxychloroquine-Loaded Anti-CD20 Nanoparticles
2013
Current B-cell disorder treatments take advantage of dose-intensive chemotherapy regimens and immunotherapy via use of monoclonal antibodies. Unfortunately, they may lead to insufficient tumor distribution of therapeutic agents, and often cause adverse effects on patients. In this contribution, we propose a novel therapeutic approach in which relatively high doses of Hydroxychloroquine and Chlorambucil were loaded into biodegradable nanoparticles coated with an anti-CD20 antibody. We demonstrate their ability to effectively target and internalize in tumor B-cells. Moreover, these nanoparticles were able to kill not only p53 mutated/deleted lymphoma cell lines expressing a low amount of CD20…
New agents and approaches for targeting the RAS/RAF/MEK/ERK and PI3K/AKT/mTOR cell survival pathways.
2012
The Ras/Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR cascades are often activated by genetic alterations in upstream signaling molecules such as receptor tyrosine kinases (RTK). Targeting these pathways is often complex and can result in pathway activation depending on the presence of upstream mutations (e.g., Raf inhibitors induce Raf activation in cells with wild type (WT) RAF in the presence of mutant, activated RAS) and rapamycin can induce Akt activation. Targeting with inhibitors directed at two constituents of the same pathway or two different signaling pathways may be a more effective approach. This review will first evaluate potential uses of Raf, MEK, PI3K, Akt and mTOR inhibitors that have…
The role of wild-type and mutated N-ras in the malignant transformation of liver cells
2000
In order to determine the role of N-ras overexpression and mutation in malignant liver cell transformation, wild-type and mutated N-ras were transfected into the rat liver epithelial cell line OC/CDE 22, and N-ras expression, growth kinetics, growth in soft agar, and tumorigenicity in vivo as well as the involvement of the mitogen-activated protein kinase (MAPK) signal transduction pathway in the expression of the malignant phenotype were analyzed. Although OC/CDE 22 cells transfected with wild-type N-ras showed a high expression of N-ras at the mRNA and protein levels, the cells did not grow in soft agar and were not tumorigenic in vivo. In contrast, OC/CDE 22 cells transfected with mutate…