- Chip-Based P450 Drug Metabolism Coupled to Electrospray Ionization-Mass Spectrometry Detection
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A chip-based P450 in vitro metabolism assay coupled with ESI-MS and ESI-MS/MS detection is described in this paper. The chips were made of a cyclic olefin polymer using a hot embossing process. The introduction of reagent solutions into the chip was carried out using fused-silica capillaries coupled to two syringes with the flow rate controlled by a syringe pump. Initial experiments described here employed a small commercial guard column in an off-chip format to desalt and concentrate the products of the enzymatic reaction prior to ESI-MS analysis. The system was used both to yield the Michaelis constant (Km) of the P450 biotransformation of imipramine into desipramine and to determine the IC50 value of a chemical inhibitor (tranylcypromine) for this CYP2C19-mediated reaction. The results demonstrated that the kinetics of the reaction inside the 4-μL volume within the channels of the cyclic olefin polymer chip provided results in agreement with those reported in the literature using conventional assays. The above reactions were carried out using human liver microsomes, and the metabolites were detected by ESI-MS showing the potential of the chip-based P450 reaction for metabolite screening studies as well as for P450 inhibition assays. A porous monolithic column was subsequently integrated into the chip to perform the reaction mixture cleanup process in an integrated fashion on the chip that is necessary for ESI-MS detection. The miniature monolithic SPE column was prepared in situ inside the chip via UV-initiated polymerization. The results obtained using the integrated system demonstrated the possibility of performing P450 enzymatic reactions in a microvolume reaction chamber coupled directly to ESI-MS detection and required less than 4 μg of HLM protein.
- Benetton, Salete,Kameoka, Jun,Tan, Aimin,Wachs, Timothy,Craighead, Harold,Henion, Jack D.
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Read Online
- Demethylation of imipramine by enteric bacteria
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The ability of a number of aerobic and anerobic bacteria to N-demethylate imipramine (I) to desipramine (II) has been investigated. Of the bacteria investigated, almost half were well known inhabitants of the human GI tract. More than half of the enteric bacteria studied were capable of N-demethylating imipramine (I) to desipramine (II) to some extent in at least one medium. It was found that the medium in which the organism was grown had a significant effect on the N-demethylase activity observed.
- Clark,Clinton,Baker,Hufford
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Read Online
- Bacterial Biosynthetic P450 Enzyme PikCD50N: A Potential Biocatalyst for the Preparation of Human Drug Metabolites
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Human drug metabolites (HDMs) are important chemicals widely used in drug-related studies. However, acquiring these enzyme-derived and regio-/stereo-selectively modified compounds through chemical approaches is complicated. PikC is a biosynthetic P450 enz
- Cheng, Fangyuan,Du, Lei,Durairaj, Pradeepraj,Guo, Jiawei,Li, Fengwei,Li, Shengying,Liu, Xiaohui,Long, Xiangtian,Ma, Li,Tang, Dandan,Zhang, Gang,Zhang, Wei,Zhang, Xingwang
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p. 14563 - 14571
(2021/11/12)
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- Manganese-Catalyzed Anti-Markovnikov Hydroamination of Allyl Alcohols via Hydrogen-Borrowing Catalysis
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Controlling the selectivity in a hydroamination reaction is an extremely challenging yet highly desirable task for the diversification of amines. In this article, a selective formal anti-Markovnikov hydroamination of allyl alcohols is presented. It enables the versatile synthesis of valuable γ-amino alcohol building blocks. A phosphine-free Earth's abundant manganese(I) complex catalyzed the reaction under hydrogen-borrowing conditions. A vast range of aliphatic, aromatic amines, drug molecules, and natural product derivatives underwent successful hydroamination with primary and secondary allylic alcohols with excellent functional group tolerance (57 examples). The catalysis could be performed on a gram scale and has been applied for the synthesis of drug molecules. The mechanistic studies revealed the metal-ligand bifunctionality as well as hemilability of the ligand backbone as the key design principle for the success of this catalysis.
- Das, Kuhali,Sarkar, Koushik,Maji, Biplab
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p. 7060 - 7069
(2021/06/30)
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- A Focused Library of Psychotropic Analogues with Neuroprotective and Neuroregenerative Potential
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Overcoming the lack of effective treatments and the continuous clinical trial failures in neurodegenerative drug discovery might require a shift from the prevailing paradigm targeting pathogenesis to the one targeting simultaneously neuroprotection and neuroregeneration. In the studies reported herein, we sought to identify small molecules that might exert neuroprotective and neuroregenerative potential as tools against neurodegenerative diseases. In doing so, we started from the reported neuroprotective/neuroregenerative mechanisms of psychotropic drugs featuring a tricyclic alkylamine scaffold. Thus, we designed a focused-chemical library of 36 entries aimed at exploring the structural requirements for efficient neuroprotective/neuroregenerative cellular activity, without the manifestation of toxicity. To this aim, we developed a synthetic protocol, which overcame the limited applicability of previously reported procedures. Next, we evaluated the synthesized compounds through a phenotypic screening pipeline, based on primary neuronal systems. Phenothiazine 2Bc showed improved neuroregenerative and neuroprotective properties with respect to reference drug desipramine (2Aa). Importantly, we have also shown that 2Bc outperformed currently available drugs in cell models of Alzheimer's and Parkinson's diseases and attenuates microglial activation by reducing iNOS expression.
- Uliassi, Elisa,Pena-Altamira, Luis Emiliano,Morales, Aixa V.,Massenzio, Francesca,Petralla, Sabrina,Rossi, Michele,Roberti, Marinella,Martinez Gonzalez, Loreto,Martinez, Ana,Monti, Barbara,Bolognesi, Maria Laura
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p. 279 - 294
(2018/10/20)
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- NB 06: From a simple lysosomotropic aSMase inhibitor to tools for elucidating the role of lysosomes in signaling apoptosis and LPS-induced inflammation
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Ceramide generation is involved in signal transduction of cellular stress response, in particular during stress-induced apoptosis in response to stimuli such as minimally modified Low-density lipoproteins, TNFalpha and exogenous C6-ceramide. In this paper we describe 48 diverse synthetic products and evaluate their lysosomotropic and acid sphingomyelinase inhibiting activities in macrophages. A stimuli-induced increase of C16-ceramide in macrophages can be almost completely suppressed by representative compound NB 06 providing an effective protection of macrophages against apoptosis. Compounds like NB 06 thus offer highly interesting fields of application besides prevention of apoptosis of macrophages in atherosclerotic plaques in vessel walls. Most importantly, they can be used for blocking pH-dependent lysosomal processes and enzymes in general as well as for analyzing lysosomal dependent cellular signaling. Modulation of gene expression of several prominent inflammatory messengers IL1B, IL6, IL23A, CCL4 and CCL20 further indicate potentially beneficial effects in the field of (systemic) infections involving bacterial endotoxins like LPS or infections with influenza A virus.
- Blaess, Markus,Bibak, Nelly,Claus, Ralf A.,Kohl, Matthias,Bonaterra, Gabriel A.,Kinscherf, Ralf,Laufer, Stefan,Deigner, Hans-Peter
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- The use of in vitro data and physiologically-based pharmacokinetic modeling to predict drug metabolite exposure: Desipramine exposure in cytochrome p4502d6 extensive and poor metabolizers following administration of imipramine
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Major circulating drug metabolites can be as important as the drugs themselves in efficacy and safety, so establishing methods whereby exposure to major metabolites following administration of parent drug can be predicted is important. In this study, imipramine, a tricyclic antidepressant, and itsmajor metabolite desipramine were selected as a model system to develop metabolite prediction methods. Imipramine undergoes N-demethylation to form the activemetabolite desipramine, and both imipramine and desipramine are converted to hydroxylated metabolites by the polymorphic enzyme CYP2D6. The objective of the present study is to determine whether the human pharmacokinetics of desipramine following dosing of imipramine can be predicted using static and dynamic physiologically-based pharmacokinetic (PBPK) models from in vitro input data for CYP2D6 extensive metabolizer (EM) and poor metabolizer (PM) populations. The intrinsic metabolic clearances of parent drug andmetabolite were estimated using human liver microsomes (CYP2D6 PM and EM) and hepatocytes. Passive diffusion clearance of desipramine, used in the estimation of availability of the metabolite, was predicted from passive permeability and hepatocyte surface area. The predicted area under the curve (AUCm/AUCp) of desipramine/imipramine was 12- to 20-fold higher in PM compared with EM subjects following i.v. or oral doses of imipramine using the static model. Moreover, the PBPK model was able to recover simultaneously plasma profiles of imipramine and desipramine in populations with different phenotypes of CYP2D6. This example suggested that mechanistic PBPK modeling combined with information obtained from in vitro studies can provide quantitative solutions to predict in vivo pharmacokinetics of drugs and major metabolites in a target human population.
- Nguyen, Hoa Q.,Callegari, Ernesto,Obach, R. Scott
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p. 1569 - 1578
(2016/10/11)
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- OLIGOMER-TRICYCLIC CONJUGATES
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The invention provides small molecule drugs that are chemically modified by covalent attachment of a water soluble oligomer. A conjugate of the invention, when administered by any of a number of administration routes, exhibits characteristics that are different from the characteristics of the small molecule drug not attached to the water soluble oligomer.
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Paragraph 0270; 0273
(2016/10/10)
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- Synthesis, Structure-activity relationship, and mode-of-action studies of antimalarial reversed chloroquine compounds
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We have previously shown that a "reversed chloroquine (RCQ)" molecule, composed of a chloroquine-like moiety and a resistance reversal-like moiety, can overcome chloroquine resistance in P. falciparum (Burgess, S. J.; Selzer, A.; Kelly, J. X.; Smilkstein, M. J.; Riscoe, M. K.; Peyton, D. H. J. Med. Chem. 2006, 49, 5623. Andrews, S.; Burgess, S. J.; Skaalrud, D.; Kelly, J. X.; Peyton, D. H. J. Med. Chem. 2010, 53, 916). Here, we present an investigation into the Structure-activity relationship of the RCQ structures, resulting in an orally active molecule with good in vitro and in vivo antimalarial activity. We also present evidence of the mode of action, indicating that the RCQ molecules inhibit hemozoin formation in the parasite's digestive vacuole in a manner similar to that of chloroquine.
- Burgess, Steven J.,Kelly, Jane X.,Shomloo, Shawheen,Wittlin, Sergio,Brun, Reto,Liebmann, Katherine,Peyton, David H.
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experimental part
p. 6477 - 6489
(2010/11/05)
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- PAINKILLING ASSOCIATION COMPRISING A DIHYDROIMIDAZOPYRAZINE DERIVATIVE
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The invention relates to a product comprising (1R)-1-[(({2R)-2-amino-3-[(8S)-8-(cyclohexylmethyl) -2-phenyl-5,6-dihydroimidazo [1,2-a]pyrazin-7(8H)-yl]-3-oxopropyl}dithio)methyl]-2-[(8S)-8-(cyclohexylmethyl) -2-phenyl-5,6-dihydrolmidazo[1,2-a]pyrazin-7(8H)-yl]-2-oxoethylamine in association with an analgesic agent selected from morphine, the similar or a morphine derivative, sodium channel inhibitors, non-steroidal antiflammatory agents (AINS), glutamatergic system inhibitors, tricycle antidepressants and gabaergic derivatives for simultaneous therapeutic use which is separated or out over the time for pain treatment or prevention.
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- Process for producing 1,3-dialkyl-2-imidazolidinone compound
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There is provided a process for preparing a 1,3-dialkyl-2-imidazolidinone by using an alkylene oxide as a first component, using at least one of (A) carbon dioxide and a monoalkylamine; (B) a carbon dioxide compound of the monoalkylamine; and (C) an 1,3-dialkylurea, reacting the first and second components by heating at 50 ° C. or higher to give 1,3-dialkyl-2-imidazolidinone, characterized in that the total molar amount of a molar feed amount of the monoalkylamine included in the component (A), a molar feed amount of the monoalkylamine part of the carbon dioxide compound of monoalkylamine, component (B), and the double of a molar feed amount of the 1,3-dialkylurea, component (C), is at least three folds of a molar feed amount of the alkylene oxide. The preparation process of this invention uses an industrially readily available alkylene oxide as a starting material and can be suitably conducted with a higher yield in an industrial scale.
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- 1,3-dialkyl-2-imidazolidinones and a manufacturing process therefor
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This invention provides a convenient process for manufacturing 1,3-dialkyl-2-imidazolidinones in a direct one-step reaction from industrially available alkylene carbonate, N-alkylethanolamine or 1,2-diol, which can minimize forming solid materials and be readily conducted in an industrial large-scale production with a higher yield and less byproducts. The process is characterized in that alkylene carbonate, N-alkylethanolamine or 1,2-diol is reacted with monoalkylamine and carbon dioxide, alkylcarbamate alkylamine salt, and/or 1,3-dialkylurea, by heating them at 50° C. or higher in a reactor whose area in contact with at least part of the reactants and/or products is made of a metal comprising titanium or zirconium and/or an oxide thereof or inorganic glass.
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- High purity 1,3-dialkyl-2-imidazolidinone and preparation process of same
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In a process for reacting N,N'-dialkylethylenediamine with urea in an aprotic polar solvent to prepare 1,3-dialkyl-2-imidazolidinone, a process comprising progressing the reaction while continuously adding N,N'-dialkylethylnediamine and urea into the aprotic polar solvent. The process is a high-yield manufacturing process in industry capable of efficiently producing very high purity 1,3-dialkyl-2-imidazolidinone which contains less than 0.1% by weight of by-product 1,3-dialkyl-2-imidazolidinimine derived from the raw materials.
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- Reappraisal of human CYP isoforms involved in imipramine N- demethylation and 2-hydroxylation: A study using microsomes obtained from putative extensive and poor metabolizers of S-mephenytoin and eleven recombinant human CYPs
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Cytochrome P450 (CYP) involved in the two major pathways of imipramine (IMI) was reappraised using human liver microsomes phenotyped for S- mephenytoin 4'-hydroxylation in vitro and 11 recombinant human CYP isoforms. Individual Eadie-Hoffstee plots for IMI N-demethylation and 2-hydroxylation showed a monophasic profile in microsomes obtained from three putative S- mephenytoin poor metabolizer (PM) livers, whereas the plots gave a biphasic relationship (except for one case in 2-hydroxylation) in those from the three extensive metabolizer (EM) livers. Effects of CYP-selective inhibitor/substrate probes on the two metabolic reactions were examined at the two IMI concentrations (2 and 400 μM) with microsomes obtained from the two PM and three EM livers. S-mephenytoin inhibited IMI N-demethylation by 50% at the low concentration in microsomes from the EM livers with no discernible effect on this pathway in those from the PM livers. Furafylline inhibited the N-demethylation by about 60% at the low and high substrate concentrations in microsomes from both the EM and PM livers. Quinidine abolished the 2-hydroxylation at the low and high concentrations in microsomes from both the EM and the PM livers. Among the recombinant human CYPs, CYP2C19, 2C18, 2D6, 1A2, 3A4 and 2B6 in rank order catalyzed the N- demethylation, whereas CYP2D6, 2C19, 1A2, 2C18 and 3A4 catalyzed the 2- hydroxylation. The K(m) values obtained from recombinant CYP2C19 and 1A2 approximated those of the high- and low-affinity components from human liver microsomes for IMI N-demethylation, respectively. For IMI 2-hydroxylation, the respective K(m) values obtained from recombinant CYP2D6 and 2C19 were close to those of the high- and low-affinity components from human liver microsomes. Our human liver microsomal study using the near-therapeutic IMI concentration (2 μM) suggests that 1) CYP2C19 and 1A2 are involved in the N- demethylation and the 2-hydroxylation is mediated exclusively by CYP2D6 and partially by CYP2C19 in the EM livers, and 2) CYP1A2 and 2D6 play a major role in IMI N-demethylation and 2-hydroxylation, respectively, in the PM livers. Our recombinant human CYP isoform study, in general, supports this conclusion.
- Koyama, Eriko,Chiba, Kan,Tani, Masanao,Ishizaki, Takashi
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p. 1199 - 1210
(2007/10/03)
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- Reagents and methods for the quantification of imipramine or desipramine in biological fluids
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Immunoassay methods and reagents for the specific quantification of imipramine or desipramine in a test sample are disclosed. The measurement of imipramine or desipramine is accomplished in a specific immunoassay employing antibodies prepared with imipramine or desipramine derivatives of the Formula III: STR1 wherein P is an immunogenic carrier material, X is two heteroatoms, Y is a linking group comprising from 1 to 6 carbon atoms and P is an immunogenic carrier material, and wherein for imipramine, R is CH3, and for desipramine, R is H. The present invention also describes the synthesis of unique labeled reagents of the structure of the Formula IV: STR2 wherein Z is a linking group comprising 1 to 4 carbon atoms and 0 to 2 heteroatoms and Q is a detectable moiety, preferably fluorescein or a fluorescein derivative, and wherein for imipramine, R1 is CH3, and for desipramine, R1 is H.
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- Immunogenic composition against tricyclic antidepressant drugs
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An immunogenic composition for raising antisera to a drug comprising immunologically active carrier protein to which is bound at least two types of hapten, each hapten comprising a drug molecule and, optionally, a bridging group, a method of raising antisera to a drug using said immunogenic composition, and a method of alleviating an overdose of a tricyclic depressant drug comprising an effective amount of antisera raised to an immunogen.
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- Process for producing 1,3-dimethyl-2-imidazolidinone
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A process for producing 1,3-dimethyl-2-imidazolidinone with a high yield which comprises reacting N,N'-dimethylethylene diamine and/or its hydrochloride with phosgene in the presence of a substantial amount of water and a dehydrochlorinating agent. Particularly, higher yield is attained by carrying out the reaction in water medium while controlling a pH to the range of 3.0 to 10.0 by adding a dehydrochlorinating agent.
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- Catalytic N-Dealkylation of Tertiary Amines--A Biomimetic Oxygenation Reaction
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A heterogeneous catalyst system is described for N-dealkylation of tertiary amines.A large number of tertiary amines including some important synthetic drugs were N-dealkylated to give the corresponding secondary amines in 50-65percent yields.The reaction was carried out at room temperature by stirring a solution of a tertiary amine in methanol containing 10percent palladium-on-charcoal catalyst.The reaction had absolute requirement for molecular oxygen like the enzymatic dealkylation reaction.It also needed methanol to act as the reductant of molecular oxygen like the NADPH in the enzymatic reaction.A catalytic cycle similar to cytochrome P-450-catalysed oxygenation cycle is proposed for activation and transfer of oxygen to the α-carbon of tertiary amines to give unstable carbinolamines which on dissociation yield secondary amines.
- Chaudhuri, Naba K.,Servando, Ofelia,Markus, Bohdan,Galynker, Igor,Sung, Ming-Sang
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p. 899 - 903
(2007/10/02)
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- Prodrugs as drug delivery systems. XXV: Hydrolysis of oxazolidines - A potential new prodrug type
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The hydrolysis kinetics of several oxazolidines derived from (-)-ephedrine and various aldehydes and ketones were studied to assess their suitability as prodrug forms for β-amino alcohols and/or carbonyl-containing compounds. The oxazolidines were found to undergo a facile and complete hydrolysis in the pH range of 1-11 at 37°. The hydrolysis rates were subject to general acid-base catalysis by buffer substances and depended strongly on pH. Most oxazolidines showed sigmoidal pH-rate profiles with maximum rates at pH > 7-7.5. At pH 7.40 and 37° the following half-lives of hydrolysis for the various ephedrine oxazolidines were found: 5 sec (formaldehyde), 18 sec (propionaldehyde), 5 min (benzaldehyde), 5 sec (salicylaldehyde), 30 min (pivalaldehyde), 4 min (acetone), and 6 min (cyclohexanone). The reaction rates in neutral and basic solutions were shown to decrease with increasing steric effects of the substituents derived from the carbonyl component and to decrease with increasing basicity of the oxazolidines. The oxazolidines are weaker bases (pK(a) 5.2-6.9) than the parent β-amino alcohol and more lipophilic at physiological pH. It is suggested that oxazolidines can be considered as potentially useful prodrug candidates for drugs containing a β-amino alcohol moiety or carbonyl groups.
- Johansen,Bundgaard
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p. 1294 - 1298
(2007/10/02)
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- Metabolism of imipramine by microorganisms
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The microbial metabolism of imipramine was studied using selected fungal organisms. The major microbial metabolites were isolated, and their structures were established by spectroscopic analyses (particularly 13C-NMR) and by comparison with authentic samples. The microbial metabolites identified included 2-hydroxyimipramine, 10-hydroxyimipramine, iminodibenzyl, imipramine-N-oxide, and desipramine; these metabolites also have been found in mammalian metabolism studies.
- Hufford,Capiton,Clark,Baker
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p. 151 - 155
(2007/10/02)
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