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3.
Curr Drug Metab ; 7(8): 883-96, 2006 Dec.
Article in English | MEDLINE | ID: mdl-17168689

ABSTRACT

BMS-299897 is a gamma-secretase inhibitor that has the potential for treatment of Alzheimer's disease. The metabolism of [(14)C]BMS-299897 was investigated in human liver microsomes, in rat, dog, monkey and human hepatocytes and in bile duct cannulated rats. Seven metabolites (M1-M7) were identified from in vitro and in vivo studies. LC-MS/MS analysis showed that M1 and M2 were regioisomeric acylglucuronide conjugates of BMS-299897. Metabolites M3, M4 and M6 were identified as monohydroxylated metabolites of BMS-299897 and M5 was identified as the dehydrogenated product of monooxygenated BMS-299897. In vivo, 52% of the radioactive dose was excreted in bile within 0-6 h from bile duct cannulated rats following a single oral dose of 15 mg/kg of [(14)C]BMS-299897. Glucuronide conjugates, M1 and M2 accounted for 80% of the total radioactivity in rat bile. In addition to M1 and M2, M7 was observed in rat bile which was identified as a glucuronide conjugate of an oxidative metabolite M5. For structure elucidation and pharmacological activity testing of the metabolites, ten microbial cultures were screened for their ability to metabolize BMS-299897 to form these metabolites. Among them, the fungus Cunninghamella elegans produced two major oxidative metabolites M3 and M4 that had the same HPLC retention time and mass spectral properties as those found in in vitro incubations. NMR analysis indicated that M3 and M4 were stereoisomers, with the hydroxyl group on the benzylic position. However, M3 and M4 were unstable and converted to their corresponding lactones readily. Based on x-ray analysis of the synthetically prepared lactone of M3, the stereochemistry of benzylic hydroxyl group was assigned as the R configuration. Both the hydroxy metabolites (M3 and M4) and the lactone of M3 showed gamma-secretase inhibition with IC(50) values similar to that of the parent compound. This study demonstrates the usefulness of microbial systems as bioreactors to generate metabolites of BMS-299897 in large quantities for structure elucidation and activity testing. This study also demonstrates the biotransformation profile of BMS-299897 is qualitatively similar across the species including rat, dog, monkey and human which provides a basis to support rat, dog and monkey as preclinical models for toxicological testing.


Subject(s)
Amyloid Precursor Protein Secretases/antagonists & inhibitors , Butyrates/metabolism , Cunninghamella/metabolism , Enzyme Inhibitors/metabolism , Hydrocarbons, Halogenated/metabolism , Animals , Bile/metabolism , Bioreactors , Biotransformation , Butyrates/chemical synthesis , Butyrates/pharmacology , Carbon Radioisotopes , Cell Line, Tumor , Cells, Cultured , Dogs , Drug Evaluation, Preclinical , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Glucuronides/metabolism , Hepatocytes/metabolism , Humans , Hydrocarbons, Halogenated/chemical synthesis , Hydrocarbons, Halogenated/pharmacology , Macaca fascicularis , Male , Microsomes, Liver/metabolism , Rats , Rats, Sprague-Dawley
4.
Bioorg Med Chem ; 12(17): 4601-11, 2004 Sep 01.
Article in English | MEDLINE | ID: mdl-15358287

ABSTRACT

A series of fluoren-9-yl ethyl amides (2) were synthesized and evaluated for human melatonin MT(1) and MT(2) receptor binding. N-[2-(2,7-dimethoxyfluoren-9-yl)ethyl]propanamide (2b) was selected and evaluated in functional assays measuring intrinsic activity at the human MT(1) and MT(2) receptors and demonstrated full agonism at both receptors. The chronobiotic properties of 2b were demonstrated in both acute and chronic rat models where 2b produced an acute phase advance of 32 min at 1mg/kg and chronically entrained free-running rats with a mean effective dose of 0.23 mg/kg. Compound 2b is significantly less efficacious than melatonin in constricting human coronary artery.


Subject(s)
Chronobiology Phenomena/physiology , Fluorenes/chemistry , Melatonin/metabolism , Amides/chemical synthesis , Amides/pharmacology , Animals , Binding Sites , Dose-Response Relationship, Drug , Humans , Mice , NIH 3T3 Cells , Radioligand Assay , Rats , Receptors, Melatonin/metabolism , Structure-Activity Relationship
5.
Bioorg Med Chem Lett ; 13(6): 1199-202, 2003 Mar 24.
Article in English | MEDLINE | ID: mdl-12643943

ABSTRACT

Optimization of a benzyl piperazine pharmacophore produced N-acyl-4-indanyl-piperazines that bind with high affinity to melatonergic MT(2) receptors. (R)-4-(2,3-dihydro-6-methoxy-1H-inden-1-yl)-N-ethyl-1-piperazine-carboxamide fumarate (13) is a water soluble, selective MT(2) agonist, which produces advances in circadian phase in rats at doses of 1-56 mg/kg that are no different from those of melatonin at 1 mg/kg. Unlike melatonin, 13 produced only weak contractile effects in rat tail artery.


Subject(s)
Piperazines/chemical synthesis , Piperazines/pharmacology , Receptors, Cell Surface/agonists , Receptors, Cytoplasmic and Nuclear/agonists , 3T3 Cells , Adenylyl Cyclases/metabolism , Animals , Circadian Rhythm/drug effects , Humans , In Vitro Techniques , Indicators and Reagents , Male , Mice , Muscle Contraction/drug effects , Muscle, Smooth, Vascular/drug effects , Piperazines/metabolism , Rats , Rats, Long-Evans , Receptors, Cell Surface/metabolism , Receptors, Cytoplasmic and Nuclear/metabolism , Receptors, Melatonin
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