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1.
Some 17 strains of filamentous fungi, encompassing 13 different species, were tested for their ability to decolorize the
polymeric dye R-478. Decolorization was observed with both living and dead mycelia of the three Aspergillus species tested, indicating bioadsorption, not biodegradation. With mycelia of other strains tested, the most decolorization
was obtained with Marasmiellus troyanus, Pleurotus sapidus, and Pleurotus ostreatus; with extracellular filtrates, the most decolorization was observed with Laetiporus sulphureus. Parallel experiments incubating benzo[a]pyrene (B[a]P) with mycelia and filtrates showed that six of the species removed
over 40% of B[a]P in comparison with HgCl2-killed controls. The highest B[a]P removal by mycelia was shown by M. troyanus (95.0%); the highest level by extracellular filtrates was shown by Hericium erinaceous (44.8%). With the exception of A. ochraceous, no products of B[a]P metabolism were detected for any of the species tested. For most species, the disappearance of B[a]P
was correlated with the ability to decolorize poly R-478 ( r = 0.78 for mycelia; r = 0.74 for culture fluids). M. troyanus gave rise to more disappearance than decolorization. The removal of B[a]P by M. troyanus and Phanerochaete chrysosporium was compared over 30 days: M. troyanus gave significantly better removal in a biphasic pattern.
Received: 8 July 1996 / Received revision: 11 November 1996 / Accepted: 29 November 1996 相似文献
2.
【背景】真菌和细菌被认为在多环芳烃污染土壤生物修复过程中发挥协同作用,目前在真实土壤体系中开展真菌-细菌协同降解研究较少。【目的】研究真菌和细菌对不同种类多环芳烃降解的差异及对蒽和苯并[a]蒽的生物强化与协同作用。【方法】选用多环芳烃降解真菌和细菌各一株,在液体纯培养体系下分析它们对不同种类多环芳烃降解的差异,在土壤体系中采用放射性同位素示踪技术研究2种微生物对蒽和苯并[a]蒽的生物强化与协同作用。【结果】供试细菌鞘脂菌NS7能够很好地降解低环种类多环芳烃,以蒽作为唯一碳源时可以将其完全降解,在复合污染条件下对菲、蒽、荧蒽、芘等降解效果突出(>90%),对苯并[a]芘降解效果较差(9.76%)。相比而言,供试真菌糙皮侧耳菌对苯并[a]芘具有更好的降解效果(21.18%),对低环多环芳烃降解效果明显不如降解菌NS7。在自然土壤中,蒽和苯并[a]蒽具有明显不同的矿化效率,分别为18.61%和4.28%,在蒽污染土壤中加入鞘脂菌NS7并未显著提高蒽的矿化率(P>0.05),相比而言,苯并[a]蒽污染土壤中加入糙皮侧耳显著提高了污染物矿化效率(2.24倍),表明真菌和细菌在土壤环境... 相似文献
3.
ABSTRACT?The co-metabolism of benzo[a]pyrene (B[a]P) and the capacity of the fungus Trichoderma reesei FS10-C to bioremediate an aged polycyclic aromatic hydrocarbon (PAH)-contaminated soil were investigated. The fungal isolate removed about 54% of B[a]P (20 mg L?1) after 12 days of incubation with glucose (10 g L?1) supplementation as a co-metabolic substrate. Bioaugmented microcosms showed a 25% decrease in total PAH concentrations in soil after 28 days, and the degradation percentages of 3-, 4-, and 5(+6)-ring PAHs were 36%, 35%, and 25%, respectively. In addition, bioaugmented microcosms exhibited higher dehydrogenase (DHA) and fluorescein diacetate hydrolysis (FDAH) activities and increased average well-color development (AWCD), Shannon-Weaver index (H), and Simpson index (D) significantly. Principal component analysis (PCA) also distinguished clear differentiation between treatments, indicating that bioaugmentation restored the microbiological function of the PAH-contaminated soil. The results suggest that bioaugmentation by T. reesei FS10-C might be a promising bioremediation strategy for aged PAH-contaminated soils. 相似文献
4.
Lupinus albus L. were grown in rhizoboxes containing a soil amended with sparingly available Fe–P or Al–P (100 μg P g−1 soil/resin mixture). Root halves of individual plants were supplied with nutrient solution (minus P) buffered at either pH 5.5
or 7.5, to assess whether the source of mineral-bound P and/or pH influence cluster-root growth and carboxylate exudation.
The P-amended soil was mixed 3:1 (w/w) with anion-exchange resins to allow rapid fixation of carboxylates. Treatments lasted 10 weeks. Forty percent and 30% of
the root mass developed as cluster roots in plants grown on Fe–P and Al–P respectively, but cluster-root growth was the same
on root-halves grown at pH 5.5 or 7.5. Mineral-bound P source (Al– or Fe–P) had no influence on the types of carboxylates
measured in soil associated with cluster roots—citrate (and trace amounts of malate and fumarate) was the only major carboxylate
detected. The [citrate] in the rhizosphere of cluster roots decreased with increased shoot P status (suggesting a systemic
effect) and also, only for plants grown on Al–P, with decreased pH in the root environment (suggesting a local effect). In
a separate experiment using anion exchange resins pre-loaded with malate or citrate, we measured malate (50%) and citrate
(79%) recovery after 30 days in soil. We therefore, also conclude that measurements of [citrate] and [malate] at the root
surface may be underestimated and would be greater than the 40- and 1.6-μmol g−1 root DM, respectively estimated by us and others because of decomposition of carboxylates around roots prior to sampling. 相似文献
5.
The building blocks fac-[99mTc{κ3-HB(timMe)3}(CO)3] and fac-[99mTc{κ3-R(μ-H)B(timMe)2}(CO)3] [R is H (4a), Ph (5a); timMe is 2-mercapto-1-methylimidazolyl] were obtained almost quantitatively by reacting fac-[99mTc(CO)3(H2O)3]+ with the corresponding scorpionate. These compounds cross the intact blood–brain barrier in mice, with significant retention in the case of 4a and 5a. Using 4a as the lead structure, we have synthesized the functionalized complexes fac-[M{κ3-H(μ-H)B(timBu-pip)2}(CO)3] [M is Re (8), 99mTc (8a); timBu-pip is methyl[4-((2-methoxyphenyl)-1-piperazinyl)butyl](2-mercapto-1-methylimidazol-5-yl)methanamide] and fac-[M{κ
3-H(μ-H)B(timMe)(timBu-pip)}(CO)3] [M is Re (9), 99mTc (9a)] and evaluated their potential as radioactive probes for the targeting of brain 5-HT1A serotonergic receptors. The Re complexes exhibit excellent affinity [IC50=0.172 ± 0.003 nM (8); IC50=0.65 ± 0.01 nM (9)] for the 5-HT1A receptor. The radioactive congeners (99mTc) have shown an initial brain uptake of 1.38 ± 0.46%ID g−1 (8a) and 0.43 ± 0.12%ID g−1 (9a), but suffer from a relatively fast washout. 相似文献
6.
In cultures of hamster embryo cells, benzo[a]pyrene (B[a]P) is metabolized primarily in the bay region. In contrast, little or no bay region metabolism of the noncarcinogenic isomer benzo[e]pyrene (B[e]P) could be detected during 12–96-h incubations of hamster embryo cells with 4 μM [3H]B[e]P. The upper limit to 9,10-dihydro-9,10-dihydroxy-B[e]P formation is about 0.2% of the ethyl acetate-soluble metabolites ( <0.1% of the total metabolites). The major identified metabolites of B[e]P were 4,5-dihydro-4,5-dihydroxy B[e]P and the glucuronide conjugates of 3-OH-B[e]P and 4,5-dihydro-4,5-dihydroxy B[e]P. Simultaneous treatment of cells with either B[a]P or 7,8-benzoflavone (BF) did not induce bay region metabolism of [3H]B[e]P. 相似文献
7.
Large inocula of Stenotrophomonas maltophilia VUN 10,003 were used to investigate bacterial degradation of benzo[a]pyrene and dibenz[a,h]anthracene. Although strain VUN 10,003 was capable of degrading 10–15 mg l−1 of the five-ring compounds in the presence of pyrene after 63 days, further addition of pyrene after degradation of the five-ring
polycyclic aromatic hydrocarbons (PAHs) ceased did not stimulate significant decreases in the concentration of benzo[a]pyrene or dibenz[a,h]anthracene. However, pyrene was degraded to undetectable levels 21 days after its addition. The amount of benzo[a]pyrene and dibenz[a,h]anthracene degraded by strain VUN 10,003 was not affected by the initial concentration of the compounds when tested at 25–100
mg l−1, by the accumulation of by-products from pyrene catabolism or a loss of ability by the cells to catabolise benzo[a]pyrene or dibenz[a,h]anthracene. Metabolite or by-product repression was suspected to be responsible for the inhibition: By-products from the
degradation of the five-ring compounds inhibited their further degradation. Journal of Industrial Microbiology & Biotechnology (2002) 28, 88–96 DOI: 10.1038/sj/jim/7000216
Received 30 January 2001/ Accepted in revised form 10 October 2001 相似文献
8.
Chlorophyll a (Chl a) seasonality was investigated in four shallow eutrophic lakes located in north-central British Columbia (western Canada).
Chlorophyll a concentration maxima in all four lakes occurred during the late summer/early autumn when near-surface total phosphorus ([Tot-P])
and total dissolved P concentrations, pH, and water temperature were highest. Mass balance and inferential analyses showed
that bloom-triggering P loads came mostly from within-lake sources, but that mechanisms controlling internal loading in Charlie
and Tabor (lakes having hypolimnetic oxygen deficits during summer) were fundamentally different than those in Nulki and Tachick
(isothermal, well oxygenated lakes). Although the timing and intensity of major blooms were associated with late summer/early
autumn P loads, average summer [Chl a] were predicted well by previously developed models based solely on spring overturn [Tot-P]. Instantaneous within-lake [Chl
a] were best predicted by models incorporating both surface [Tot-P] and temperature (r
2 = 0.57–0.70). Moreover, [Tot-P] and temperature combined accounted for 57% of among-lake variations in instantaneous [Chl
a]: log [Chl a] = 0.038 (°C) + 0.006 ([Tot-P]) + 0.203 (P < 0.001), where [Chl a] and [Tot-P] are in μg l−1. Positive associations between instantaneous [Chl a] and temperature support climate change models that forecast changes in phytoplankton productivity even if nutrient loading
rates remain constant.
Handling editor: D. Hamilton 相似文献
9.
Angeli JP Ribeiro LR Gonzaga ML Soares Sde A Ricardo MP Tsuboy MS Stidl R Knasmueller S Linhares RE Mantovani MS 《Cell biology and toxicology》2006,22(4):285-291
β-Glucans (BGs) are polysaccharides that are found in the cell walls of organisms such as bacteria, fungi, and some cereals.
The objective of the present study was to investigate the genotoxic and antigenotoxic effects of BG extracted from the mushroom
Agaricus brasiliensis (= Agaricus blazei Murrill ss. Heinemann). The mutagenic activity of BG was tested in single-cell gel electrophoresis assays with human peripheral lymphocytes. In addition,
the protective effects against the cooked food mutagen 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) and (+/−)-anti-B[a]P-7,8-dihydrodiol-9,10-epoxide (BPDE), which is the main metabolite of B[a]P, and against ROS (H2O2)-induced DNA damage, were studied. The results showed that the compound itself was devoid of mutagenic activity, and that
a significant dose-dependent protective effect against damage induced by hydrogen peroxide and Trp-P-2 occurred in the dose
range 20–80 μg/ml. To investigate the prevention of Trp-P-2-induced DNA damage, a binding assay was carried out to determine
whether BG inactivates the amine via direct binding. Since no such interactions were observed, it is likely that BG interacts
with enzymes involved in the metabolism of the amine. 相似文献
10.
Diallyl sulfide (DAS) and diallyl disulfide (DADS) at 25 g ml–1decreased the benzo[a]pyrene (B[a]P)-induced colony growth inhibition of human epidermal keratinocytes. DAS and DADS decreased B[a]P-DNA and B[a]P-protein adducts by 65% and 49–55%, respectively. The B[a]P-induced ethoxyresorufin O-deethylase activity, a marker enzyme for cytochrome P450 1, was decreased from 3 to 1.7–1.9 nmol min–1 mg–1 microsomal protein by DAS and DADS treatments. The activity of glutathione S-transferase, a detoxifying enzyme for B[a]P, but was decreased by DADS, but was unaffected by DAS. 相似文献
11.
M. Wolter F. Zadrazil R. Martens M. Bahadir 《Applied microbiology and biotechnology》1997,48(3):398-404
The degradation of eight unlabeled highly condensed polycyclic aromatic hydrocarbons (PAH) and the mineralization of three
14C-labeled PAH by the white-rot fungus Pleurotus sp. Florida was investigated. Three concentrations containing 50, 250 or 1250 μg each unlabeled PAH/5 g straw were added
to sterile sea sand. Selected treatments were added subsequently with 14C-labeled pyrene, benzo[a]anthracene or benzo[a]pyrene. The PAH-loaded sea sand was then mixed into straw substrate and incubated. The disappearance of the unlabeled four-to
six-ring PAH: pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenz[a,h]anthracene and benzo[ghi]perylene, was determined by high-performance liquid chromatography. After 15 weeks of incubation, the recoveries were less
than 25% for initial amounts of 50 μg (controls above 85%). The recoveries of unlabeled PAH increased in the inoculated samples
with increasing concentrations applied. No correlation could be determined between the number of condensed rings of the PAH
and the recoveries of added PAH. Pleurotus sp. Florida mineralized 53% [14C]pyrene, 25% [14C]benzo[a]anthracene and 39% [14C]benzo[a]pyrene to 14CO2 in the presence of eight unlabeled PAH (50 μg applied) within 15 weeks. During the course of cultivation, Pleurotus sp. Florida degraded more than 40% of the wheat straw substrate. Variation of the initial concentration of PAH did not influence
the extent of degradation of the organic matter.
Received: 16 December 1996 / Received revision: 17 March 1997 / Accepted: 22 March 1997 相似文献
12.
P. Simon M. Lafontaine P. Delsaut Y. Morele T. Nicot 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2000,748(2):1183
3-Hydroxybenzo[a]pyrene (3-OHB[a]P), one of the metabolites of benzo[a]pyrene (B[a]P), has been determined in human urine using an automated column-switching procedure. The hydrolysed biological sample is centrifuged just prior to being injected into a reusable precolumn loop, which is packed with a preparative phase and coupled on-line to a liquid chromatographic (LC) system. A rapid pre-treatment of the hydrolysed sample, consisting of a concentration and a crude clean-up, is performed on the precolumn. The analytes are then non-selectively desorbed with the LC eluent and the sample is cleaned again in three successive purification columns using the direct transfer or “heart-cut” technique. The pre-treatment does not exceed 3 min. and the entire analytical purification and separation procedure takes less than 30 min. Average 3-OHB[a]P recovery reaches 95% in the 1–50 ng/l range of urine, and the detection limit is 0.1 ng/l urine for a 3 ml injection of hydrolysed urine. The developed method was compared with a more time-consuming off-line method to analyse urines of B[a]P gavaged rats; the statistical treatment indicates that both methods are in agreement. The method was applied to purify and concentrate the urine samples of workers exposed and apparently unexposed to polycyclic aromatic hydrocarbons (PAHs). 相似文献
13.
The white-rot fungi Trametes versicolor PRL 572, Trametes versicolor MUCL 28407, Pleurotus ostreatus MUCL 29527, Pleurotus sajor-caju MUCL 29757 and Phanerochaete chrysosporium DSM 1556 were investigated for their ability to degrade the polycyclic aromatic hydrocarbons (PAH) anthracene, benz[a]anthracene and dibenz[a,h]anthracene in soil. The fungi were grown on wheat straw and mixed with artificially contaminated soil. The results of this
study show that, in a heterogeneous soil environment, the fungi have different abilities to degrade PAH, with Trametes showing little or no accumulation of dead-end metabolites and Phanerochaete and Pleurotus showing almost complete conversion of anthracene to 9,10-anthracenedione. In contrast to earlier studies, Phanerochaete showed the ability to degrade the accumulated 9,10-anthracenedione while Pleurotus did not. This proves that, in a heterogeneous soil system, the PAH degradation pattern for white-rot fungi can be quite different
from that in a controlled liquid system.
Received: 20 March 1996 / Received revision: 2 July 1996 / Accepted: 8 July 1996 相似文献
14.
M. Dr∢žkiewicz 《Folia microbiologica》1996,41(3):272-276
A structure of fungal flora was studied in aggregates of various diameter in a chernozemic rendzina and a lessivè soil. Aggregate
diameter influenced strongly the distribution of fungi such asCephalosporium, Fusarium, Penicillium and sterile mycelia. The percentage of the above fungi changed with changing aggregate diameter as follows:Cephalosporium: 1–3>5–7 >0.5 in lessivè soil and ≤0.5>5–7>1–3 in chernozemic rendzina,Fusarium: ≤0.5>1–3>5–7 in lessivè soil and 5–7>1–3>0.5 in chernozemic rendzina,Penicillium: 5–7>0.5>1–3 in lessivè soil and 1–3>0.5>5–7 in chernozemic rendzina. The effect of aggregate size on the generic composition
of fungal flora in the outer and inner parts of the aggregates was weaker than on that in the whole aggregates. This held
especially forCephalosporium, Fusarium and sterile mycelia in the outer part of aggregates andPenicillum in the inner one. Moreover, the percentage of some fungi in whole aggregates of both soils was affected byV
a/V
w in the aggregates. Additional effect in lessivè soil aggregates was that of the percentage of pores measuring 0.1–0.05 μm.
Some pores affected the contents of some fungi in the outer part of the aggregates of both soils and in the inner one of chernozemic
rendzina aggregates. 相似文献
15.
Soil samples from an agricultural field contaminated with 10 ppm14C-benz(a)anthracene in glass tubes were brought into contact with cultures of wood-rotting fungi, precultivated on wheat straw substrate.
Forty-five strains of white-rot fungi and four brown-rot fungi were tested for their ability to colonize the soil and to mineralize14C-benz(a)anthracene to14CO2 within a 20-week incubation time. Twenty-two white-rot fungi and all brown-rot fungi were unable to colonize the soil. Twenty-three
strains of white-rot fungi, all belonging to the genusPleurotus, colonized the soil. During the experiment the noncolonizing fungi and their substrate disintegrated more and more to a nonstructured
pulp from which water diffused into the soil. The same phenomenon was observed in the control which contained only straw without
fungus and contaminated soil. In samples with colonizing fungi the substrate as well as the mycelia in the soil remained visibly
unchanged during the entire experiment. Surprisingly, most samples with fungi not colonizing the soil and the control without
fungus liberated between 40 and 58 % of the applied radioactivity as14CO2 whereas the samples with the colonizing fungi respired only 15–25 % as14CO2. This was 3–5 times more14CO2 than that liberated from the control (4.9 %) which contained only contaminated soil without straw and fungus. A similar result
was obtained with selected colonizing and noncolonizing fungi and soil contaminated with 10 ppm14C-pyrene. However, in pure culture studies in which14C-pyrene was added to the straw substrate,Pleurotus sp. (P2), as a representative of the colonizing fungi, mineralized 40.3 % of the added radioactivity to14CO2. The noncolonizing fungiDichomitus squalens andFlammulina velutipes liberated only 17.2 or 1.7 %, respectively, as14CO2. These results lead to the hypothesis that the native soil microflora stimulated by the formed products of straw lysis is
responsible for high degradation rates found with noncolonizing fungi. 相似文献
16.
R. Beaudet M.-J. Lévesque R. Villemur M. Lanthier M. Chénier F. Lépine J.-G. Bisaillon 《Applied microbiology and biotechnology》1998,50(1):135-141
Anaerobic biodegradation of pentachlorophenol (PCP) in a contaminated soil from a wood-treating industrial site was studied
in soil slurry microcosms inoculated with a PCP-degrading methanogenic consortium. When the microcosms containing 10%–40%
(w/v) soil were inoculated with the consortium, more than 90% of the PCP was removed in less than 30 days at 29 °C. Less-chlorinated
phenols, mainly 3-chlorophenol were slowly degraded and accumulated in the cultures. Addition of glucose and sodium formate
to the microcosms was not necessary, suggesting that the organic compounds in the soil can sustain the dechlorinating activity.
Inoculation of Desulfitobacterium frappieri strain PCP-1 along with a 3-chlorophenol-degrading consortium in the microcosms also resulted in the rapid dechlorination
of PCP and the slow degradation of 3-chlorophenol. Competitive polymerase chain reaction experiments showed that PCP-1 was
present at the same level throughout the 21-day biotreatment. D. frappieri, strain PCP-1, inoculated into the soil microcosms, was able to remove PCP from soil containing up to 200 mg PCP/kg soil.
However, reinoculation of the strain was necessary to achieve more than 95% PCP removal with a concentration of 300 mg and
500 mg PCP/kg soil. These results demonstrate that D. frappieri strain PCP-1 can be used effectively to dechlorinate PCP to 3-chlorophenol in contaminated soils.
Received: 14 November 1997 / Received revision: 29 January 1998 / Accepted: 24 February 1998 相似文献
17.
Caixia Yuan Liping Lu Xiaoli Gao Yanbo Wu Maolin Guo Ying Li Xueqi Fu Miaoli Zhu 《Journal of biological inorganic chemistry》2009,14(6):841-851
Abstract A series of oxovanadium complexes with mixed ligands, a tridentate ONO-donor Schiff base ligand [viz., salicylidene anthranilic
acid (SAA)], and a bidentate NN ligand [viz., 2,2′-bipyridine (bpy), 1,10-phenanthroline (phen), dipyrido[3,2-d:2′,3′-f]quinoxaline (dpq), dipyrido[3,2-a:2′,3′-c]phenazine (dppz), or 7-methyldipyrido[3,2-a:2′,3′-c]phenazine (dppm)], have been synthesized and characterized by elemental analysis, electrospray ionization mass spectrometry,
UV–vis spectroscopy, Fourier transform IR spectroscopy, EPR spectroscopy, and X-ray crystallography. Crystal structures of
both complexes, [VIVO(SAA)(bpy)]·0.25bpy and [VIVO(SAA)(phen)]·0.33H2O, reveal that oxovanadium(IV) is coordinated with one nitrogen and two oxygen atoms from the Schiff base and two nitrogen
atoms from the bidentate planar ligands, in a distorted octahedral geometry (VO3N3). The oxidation state of V(IV) with d
1 configuration was confirmed by EPR spectroscopy. The speciation of VO–SAA–bpy in aqueous solution was investigated by potentiomtreic
pH titrations, and the results revealed that the main species are two ternary complexes at a pH range of 7.0–7.4, and one
is the isolated crystalline complex. The complexes have been found to be potent inhibitors against human protein tyrosine
phosphatase 1B (PTP1B) (IC50 approximately 30–61 nM), T-cell protein tyrosine phosphatase (TCPTP), and Src homology phosphatase 1 (SHP-1) in vitro. Interestingly,
the [VIVO(SAA)(bpy)] complex selectively inhibits PTP1B over the other two phosphatases (approximate ninefold selectivity against
SHP-1 and about twofold selectivity against TCPTP). Kinetics assays suggest that the complexes inhibit PTP1B in a competitive
and reversible manner. These suggest that the complexes may be promising candidates as novel antidiabetic agents.
Graphical Abstract
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
18.
19.
To test the hypothesis that polycyclic aromatic hydrocarbons capable of being converted to a reactive ester of the mesohydroxymethyl metabolite would be carcinogenic, a series of 6-substituted derivatives of benzo[a]pyrene (B[a]P) were tested for carcinogenicity in Sprague-Dawley rats by subcutaneous injection of the compound in sesame oil on alternate days for 30 doses. At the 0.2-μmol dose level B[a]P, 6-acetoxymethyl(6-AcOCH2)B[a]P, 6-hydroxymethyl(6-HOCH2)B[a]P, 6-methyl(6-CH3)B[a]P and 6-benzoyloxymethyl(6-BzOCH2)B[a]P were nearly equipotent, 6-formyl(6-OCH)-and 6-chloromethyl(6-ClCH2)B[a]P were less active, and 6-methoxymethyl (6-MeOCH2)B[a]P was inactive. At lower doses the order of potency was estimated to be: 6-AcOCH2- = 6-HOCH2- = or > B[a]P > 6-CH2- > 6-BzOCH2- > 6-ClCH2- > 6-OCH- > 6-BrCH2B[a]P. Incubation of these compounds in the presence of cofactors or cofactors plus a microsomal preparation of rat subcutis indicated that enzymic activation was necessary for metabolism to highly polar products and for conversion of 6-AcOCH2-, 6-BzOCH2- and 6-OCHB[a]P to 6-HOCH2B[a]P. The halomethyl compounds were converted to 6-HOCH2B[a]P in the absence of enzyme by hydrolysis. 6-MeOCH2B[a]P was unchanged in this system. These observations are consistent with the foregoing hypothesis with regard to derivatives of B[a]P and demonstrate that compounds of this series that are capable of conversion to the 6-HOCH2-derivatives are carcinogenic. 相似文献
20.
Burke PJ Wong LC Jenkins TC Knox RJ Stanforth SP 《Bioorganic & medicinal chemistry letters》2011,21(24):7447-7450
A series of 2-nitroaryl-1,2,3,4-tetrahydroisoquinolines 10 and nitro-substituted 5,6-dihydrobenzimidazo[2,1-a]isoquinoline N-oxides 11 have been synthesised and evaluated as potential bioreducible substrates for the enzymes NAD(P)H: quinone oxidoreductase 1 (NQO1) and Escherichia coli nitroreductase (NR). Also prepared and evaluated were 2-(3,5-dinitropyridin-2-yl)-1,2,3,4-tetrahydroisoquinoline 12 and 5,6-dihydro-10-nitropyrido[3″,2″:4′,5′]imidazo[2′,1′-a]isoquinoline 12-oxide 13. Both compounds 10b and 13 were reduced faster by human NQO1 than by CB-1954 [5-(aziridin-1-yl)-2,4-dinitrobenzamide]. 相似文献