- Tracing the transformation of labelled [1-13C]phenanthrene in a soil bioreactor
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[1-13C]-labelled phenanthrene was incubated in a closed bioreactor to study the flux and biotransformation of polycyclic aromatic hydrocarbon (PAH) in contaminated soils on a bulk and molecular level. The degradation of extractable phenanthrene was observed by GC-MS measurements and the mineralisation was monitored by 13CO2 production. The transformation of the 13C-label into non-extractable soil-bound residues was determined by carbon isotopic measurements. With these data we were able to calculate a carbon budget of the 13C-label. Moreover, the chemical structure of non- extractable bound residues was characterised by applying selective chemical degradation reactions to cleave xenobiotic subunits from the macromolecular organic soil matrix. The obtained low molecular weight products yielded 13C-labelled compounds which were identified using IRM (isotope ratio monitoring)-GC-MS and structurally characterised with GC-MS. Most of the 13C-labelled products obtained by chemical degradation of non-extractable bound residues are well-known metabolites of phenanthrene. Thus, metabolites of [1-13C]phenanthrene formed during biodegradation appear to be reactive components which are subsequently involved in the bound residue formation. Hydrolysable amino acids of the soil residues were significantly labelled with 13C as confirmed by IRM-GC-MS measurements. Therefore, phenanthrene- derived carbon was transformed by anabolic microbial processes into typical biologically derived compounds. These substances are likely to be incorporated into humic-like material after cell death. (C) 2000 Elsevier Science Ltd.
- Richnow,Annweiler,Koning,Lüth,Stegmann,Garms,Francke,Michaelis
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- 4-(Tetralin-1-yl)- and 4-(Naphthalen-1-yl)alkyl Derivatives of 1-Cyclohexylpiperazine as σ Receptor Ligands with Agonist σ 2 Activity
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Several 1-cyclohexylpiperazine derivatives related to σ2 receptor ligand 1-cyclohexyl-4-[3-(5-methoxy-1,2,3,4-tetrahydronaphthalen-1-yl)propyl] piperazine (33, Ki = 0.34 nM) were synthesized and tested in radioligand binding assays, to attempt a structure-affinity relationship study. Intermediate alkyl chain length and methoxyl group position on the tetralin nucleus were varied. A few naphthalene analogues were also prepared. High affinities were found in σ2 receptor binding for almost all compounds, some of which displayed Ki values in subnanomolar range, but low σ2/σ1 selectivities were found. The highest σ2 affinities were displayed by compounds with an intermediate alkyl chain of three (32 and 43) or five methylenes (39 and 46). Quite high σ1 receptor affinity was found for compounds with a four-methylene chain; 36 (Ki = 0.036 nM) and 45 (Ki = 0. 22 nM) displaying good (σ1/σ2 selectivity (406- and 139-fold, respectively). Moreover, homologues of compound 33 displayed also satisfactory selectivities over dopamine D2-like, serotonin 5-HT3, and adrenergic α1 receptors. These compounds and a few others were tested in the inhibition of the electrically evoked contractions in guinea pig bladder and were demonstrated to be full σ2 agonists. The activity values correlated well to the affinity scale (EC50 in μM range). 33 and related compounds are proposed as a class of potential antineoplastic and PET diagnosis agents.
- Berardi, Francesco,Ferorelli, Savina,Abate, Carmen,Colabufo, Nicola Antonio,Contino, Marialessandra,Perrone, Roberto,Tortorella, Vincenzo
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- Synthesis, pharmacology, and molecular modeling of novel 4-alkyloxy indole derivatives related to cannabimimetic aminoalkyl indoles (AAIs)
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Several novel 4-alkyloxy-aminoalkyl indole derivatives 3 were synthesized from 4-benzyloxyindole (1). Alkylation of 1 with 4-(2-chloroethyl)morpholine (NaH/HMPA) formed 2. Deprotection using palladium hydroxide on carbon/hydrogen followed by alkylation with the appropriate alkyl bromide gave the target compounds 3b-3j, the appropriate alkyl bromides 13 and 17 were prepared from the commercially available 1-naphthylethyl bromide 9 using the chain lengthening sequences as shown in Scheme 3. In receptor binding assay and in vivo testing, the long chain alkoxy compounds 3g and 3h (K(i)=127 nM) showed affinity for the CB1 receptor which was approximately 16-35-fold less than that of WIN 55,225. However, the pharmacological profile of 3h mimics that of WIN 55,212. An examination of the SAR of these analogues shows that translocating the napthyl group in AAIs from the C-3 position to C-4 via an oxygen (ether linkage) decreases activity which is in contrast to previous findings that a naphthylcarbonyl at C-4 retains activity. The present work points to the importance of the role of a keto group in the interaction with the receptor. Molecular modeling work suggest that, although reasonable superposition of key structural features between Δ9-THC and AAIs can be made, the overlay is not straightforward. The present study also illustrates the difficulty in accommodating AAIs into the cannabinoid pharmacophore and it seems likely that a unique pharmacophore will need to be developed. Only then will the similarities to and differences from the classical cannabinoid pharmacophore be clearly delineated.
- Dutta,Ryan,Thomas,Singer,Compton,Martin,Razdan
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- B(C6F5)3-Catalyzed Diastereoselective Formal (4 + 1)-Cycloaddition of Vinylcyclopropanes and Et2SiH2
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A formal (4 + 1)-cycloaddition of vinylcyclopropanes and Et2SiH2 to afford 3,4-disubstituted silolanes is reported. The reaction sequence commences with the known B(C6F5)3-catalyzed alkene hydrosilylation with dihydrosilanes. Cleavage of the remaining Si-H bond in the hydrosilylation product assisted by B(C6F5)3 leads to formation of a cyclopropane-stabilized silylium ion. The activated cyclopropane ring is then opened by the in situ-generated borohydride accompanied by ring closure to the silolane. The diastereoselectivity is rationalized by a mechanistic model.
- Long, Peng-Wei,Oestreich, Martin
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supporting information
p. 4834 - 4837
(2021/06/28)
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- Effective and reversible DNA condensation induced by bifunctional molecules containing macrocyclic polyamines and naphthyl moieties
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A series of bifunctional molecules containing macrocyclic polyamines [12]aneN3 and naphthyl moieties 1-3(a, b) have been designed and synthesized through efficient N-alkylation and copper-mediated alkyne-azide click reactions. Experiments on gel electrophoresis, dynamic light scattering and atomic force microscopy confirmed that 2b and 3b with two [12]aneN 3 units efficiently induced the DNA condensation at the concentration of 120 μM in less than 5 min. The condensation mechanism was studied by EB displacement fluorescence spectra, viscosity titration, and ionic strength effects. The condensation process was found to be reversible, and the presence of both naphthyl and [12]aneN3 units in the molecules was proved to be necessary for the effective DNA condensation inductions. Cytotoxicity assay showed that the presence of triazole moieties can result in lower toxicity.
- Yan, Hao,Li, Zhi-Fen,Guo, Zhi-Fo,Lu, Zhong-Lin,Wang, Feng,Wu, Li-Zhu
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supporting information; experimental part
p. 801 - 808
(2012/03/26)
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- AMINE COMPOUND AND PHARMACEUTICAL USE THEREOF
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Provided is a novel amine compound represented by the following formula (I) having a superior peripheral blood lymphocyte decreasing action and superior in the immunosuppressive action, rejection suppressive action and the like, which shows decreased side effects of, for example, bradycardia and the like, or a pharmaceutically acceptable acid addition salt thereof, or a hydrate thereof, or a solvate thereof. wherein each symbol is as defined in the specification.
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Page/Page column 152
(2010/04/25)
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