Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Fluorenes”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 235 records · Page 13Linked to original sources
PubMed1980

New compounds: derivatives of fluorene XXXVII: 9-substituted 3-nitrofluorenes.

New 9-substituted 3-nitrofluorenes were prepared as potential intermediates in a study of modified electrophilicity and mutagenicity of the carcinogen 3-N,O-diacetylhydroxylaminofluorene. The reported derivatives, together with some already known 9-substituted 3-nitrofluorenes, were too unstable to survive the reducing conditions required to transform the nitro group to the corresponding hydroxylamine.

Carcinogens↗
PubMed1986

Base pair substitution and frameshift mutagenesis induced by apurinic sites and two fluorene derivatives in a recA441 lexA (Def) strain.

One of the consequences of the induction of the Escherichia coli SOS system is the increased ability of the cells to perform mutagenesis. Induction of the SOS system is the result of derepression of a set of genes through a regulatory mechanism controlled by LexA and RecA. In response to an inducing signal, RecA is activated in a form that facilitates the proteolytic cleavage of LexA repressor. Previous works have shown that activated RecA plays a second role, i.e. it is required for the establishment of base pair substitution mutations promoted by UV irradiation. Using a forward mutational assay and recA441 lexA (Def) host bacteria, we show that the result can be extended not only to other mutagens promoting base pair substitution mutations (Apurinic sites, Ap sites and N-hydroxy-N-2-aminofluorene, N-OH-AF) but also mutagens promoting frameshift mutations (N-Acetoxy-N-2-acetylaminofluorene, N-AcO-AAF). In the recA441 lexA (Def) strain all the genes which are part of the lexA regulon, including recA itself, are expressed constitutively. The recA441 mutation allows RecA to acquire its activated form when the bacteria are grown at 42 degrees C. We show that in such strains Ap sites or N-OH-AF induce a high level of mutations only when the bacteria are grown at 42 degrees C. On the other hand, we show that N-AcO-AAF can promote mutations even at 30 degrees C; the number of mutations being increased when the bacteria were grown at 42 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetoxyacetylaminofluorene↗
PubMed2006

Simultaneous determination of urinary hydroxylated metabolites of naphthalene, fluorene, phenanthrene, fluoranthene and pyrene as multiple biomarkers of exposure to polycyclic aromatic hydrocarbons.

A method is presented for determining monohydroxy polycyclic aromatic hydrocarbons (OHPAHs) having 2-, 3- and 4-rings in human urine by using high-performance liquid chromatography with fluorescence detection. A urine sample containing conjugates of OHPAHs was hydrolysed in the presence of beta-glucuronidase/aryl sulfatase and the solution was cleaned up with a solid-phase extraction (C(18) and silica). Eight OHPAHs, namely 1- and 2-hydroxynaphthalenes, 2-hydroxyfluorene, 2-, 3- and 4-hydroxyphenanthrenes, 3-hydroxyfluoranthene and 1-hydroxypyrene, were separated and 1- and 9-hydroxyphenanthrenes co-eluted on an alkylamide-type reversed-phase column with fluorimetric detection. The urinary concentrations of OHPAHs were quantified by using deuterated 1-hydoxypyrene as an internal standard. The method showed good repeatability for inter- and intra-day precisions as well as good linearity of calibration curves (r (2) ranged from 0.996 to 0.999). The limits of detection (S/N=3) were in the range from 2.3 fmol to 2.2 pmol per injection. This method was successfully applied to urine samples from non-smoking taxi drivers, traffic policemen and rural villagers of Chiang Mai, Thailand. The results showed higher urinary concentrations of OHPAHs in rural villagers, consistent with higher respiratory exposure to PAHs.

Adult↗