Synthesis and biological evaluation of constrained analogues of the opioid peptide H‐Tyr‐d‐Ala‐Phe‐Gly‐NH2 using the 4‐amino‐2‐benzazepin‐3‐one scaffold

Abstract: The synthesis of conformationally restricted dipeptidic moieties 4‐amino‐1,2,4,5‐tetrahydro‐2‐benzazepin‐3‐one (Aba)‐Gly ([(4S)‐amino‐3‐oxo‐1,2,4,5‐tetrahydro‐1H‐2‐benzazepin‐2‐yl]‐acetic acid) and 8‐hydroxy‐4‐amino‐1,2,4,5‐tetrahydro‐2‐benzazepin‐3‐one (Hba)‐d ‐Ala ([(4S)‐amino‐8‐hydroxy‐3‐oxo‐1,2,4,5‐tetrahydro‐benzo[c]azepin‐2‐yl]‐propionic acid) was based on a synthetic strategy that uses an oxazolidinone as an N‐acyliminium precursor. Introducing these Aba scaffolds into the N‐terminal tetrapeptide of dermorphin (H‐Tyr‐d ‐Ala‐Phe‐Gly‐Tyr‐Pro‐Ser‐NH₂)‐induced remarkable shifts in affinity and selectivity towards the opioid μ‐ and δ‐receptors. This paper provides the synthesis and biological in vitro and in vivo evaluation of constricted analogues of the N‐terminal tetrapeptide H‐Tyr‐d ‐Ala‐Phe‐Gly‐NH₂, which is the minimal subunit of dermorphin needed for dermorphin‐like opiate activity.     

Improving the Specificity of the Prostate‐Specific Antigen Substrate Glutaryl‐Hyp‐Ala‐Ser‐Chg‐Gln as a Promoiety

To develop PSA peptide substrates with improved specificity and plasma stability from the known substrate sequence glutaryl‐Hyp‐Ala‐Ser‐Chg‐Gln, systematic replacements of the N‐terminal segment with D‐retro‐inverso‐peptides were performed with the incorporation of 7‐amino‐4‐methylcoumarin (7‐AMC) after Gln for convenient fluorometric determination and ranking of the PSA substrate activity. The D‐retro‐inverso‐peptide conjugates with P2‐P5 D‐amino acid substitutions were moderate but poorer PSA substrates as compared to the original peptide, suggesting that inversion of the amide bonds and/or incorporation of the additional atom as in the urea linker adversely affected PSA binding. However, P5 substitution of Hyp with Ser showed significant improvements in PSA cleavage rate; the resulting AMC conjugate, glutaryl‐Ser‐Ala‐Ser‐Chg‐Gln‐AMC ( 11 ), exhibited the fastest PSA cleavage rate of 351 pmol/min/100 nmol PSA. In addition, GABA←mGly‐Ala‐Ser‐Chg‐Gln‐AMC (conjugate 6 ) was the second best PSA substrate and released 7‐AMC at a rate of 225 pmol/min/100 nmol PSA as compared to 171 pmol/min/100 nmol PSA for the control conjugate glutaryl‐Hyp‐Ala‐Ser‐Chg‐Gln‐AMC. Incubations of selected AMC conjugates with mouse and human plasma revealed that GABA←D‐Ser‐ψ[NH‐CO‐NH]‐Ala‐Ser‐Chg‐Gln‐AMC ( 5 ) and GABA←mGly‐Ala‐Ser‐Chg‐Gln‐AMC ( 6 ) were most stable to non‐PSA‐mediated proteolysis. Our results suggest that the PSA specificity of glutaryl‐Hyp‐Ala‐Ser‐Chg‐Gln is improved with Ser and mGly substitutions of Hyp at the P5.     

Solid‐phase synthesis of peptides containing the spin‐labeled 2,2,6,6‐tetramethylpiperidine‐1‐oxyl‐4‐amino‐4‐carboxylic acid (TOAC)

Abstract: 2,2,6,6‐Tetramethylpiperidine‐1‐oxyl‐4‐amino‐4‐carboxylic acid (TOAC) is a nitroxide spin‐labeled, achiral C^α‐tetrasubstituted amino acid recently shown to be not only an effective β‐turn and 3₁₀/α‐helix promoter in peptides, but also an excellent rigid electron paramagnetic resonance probe and fluorescence quencher. Here, we demonstrate that TOAC can be effectively incorporated into internal positions of peptide sequences using Fmoc chemistry and solid‐phase synthesis in an automated apparatus.     

Characterization of the dopamine D3 receptor agonist R(+)‐7‐hydroxy‐N,N‐di‐n‐propyl‐2‐aminotetralin‐induced hypo‐ and hypermotility in mice

The present study was designed to characterize the dopamine D₃ receptor agonist R(+)‐7‐hydroxy‐N,N‐di‐n‐propyl‐2‐aminotetralin (R(+)‐7‐OH‐DPAT)‐induced changes in locomotor activity in mice. Although R(+)‐7‐OH‐DPAT (0·01–10 mg/kg) produced a significant decrease in horizontal and vertical motility within 15 min after the start of behavioural measurements, the dopamine D₁ receptor antagonist R(+)‐SCH23390 (0·05 mg/kg) and the dopamine D₃ receptor antagonist (+)‐UH232 (10 mg/kg) had no antagonistic effects on the R(+)‐7‐OH‐DPAT (3 mg/kg)‐induced hypomotility, while the dopamine D₂ receptor antagonist S(−)‐sulpiride (20 mg/kg) augmented it. Although R(+)‐7‐OH‐DPAT (0·01–1 mg/kg) had no marked effects on horizontal or vertical motility, higher doses (3 and 10 mg/kg) of the drug produced a significant increase in horizontal or vertical motility from 30 to 90 min after the start of the behavioural measurements. S(−)‐sulpiride (20 mg/kg) and (+)‐UH232 (10 mg/kg) almost completely inhibited the R(+)‐7‐OH‐DPAT (3 mg/kg)‐induced hypermotility, whereas the antagonistic effects of R(+)‐SCH23390 (0·05 mg/kg) were partial. These results suggest that the R(+)‐7‐OH‐DPAT‐induced hypermotility is mediated principally via dopamine D₂ and D₃ receptors, whereas it is unlikely that the hypomotility results from the activation of presynaptic dopamine D₂ or D₃ receptors. Copyright © 1999 John Wiley & Sons, Ltd.     

Pseudopeptides containing the 2‐hydrazonoacyl fragment: analogs of the chemotactic agent HCO‐Met‐Leu‐Phe‐OMe

Abstract: In order to further examine the properties of pseudopeptides containing the 2‐hydrazonoacyl fragment, two new series of analogs of the prototypical chemotactic N‐formyl‐tripeptide HCO‐Met‐Leu‐Phe‐OMe were designed and synthesized. The first group contains the new fragment as the N‐terminal residue and is represented by the N‐aryl derivatives p‐Cl‐C₆H₄‐NH‐N=C(R)‐CO‐Leu‐Phe‐OMe ( 2 and 3 ) and by the corresponding N‐aroyl analogs p‐CH₃‐C₆H₄‐CO‐NH‐N=C(R)‐CO‐Leu‐Phe‐OMe ( 4 ). The second group contains the new fragment in place of the central Leu residue and is represented by compounds HCO‐Xaa‐NH‐N=C(R)‐CO‐Phe‐OMe ( 7a and 7b ) where Xaa is Nle and Met, respectively. The conformational and biochemical properties of the new products were examined.     

Synthesis and Antifungal Activity of 1‐Aryl‐3‐phenethylamino‐1‐propanone Hydrochlorides and 3‐Aroyl‐4‐aryl‐1‐phenethyl‐4‐piperidinols

Mono‐Mannich bases, 1‐aryl‐3‐phenethylamino‐1‐propanone hydrochlorides, 1a, 2a , 3a , 4a , 5a , 6a , 7a , 8a , 9a , and semi‐cyclic mono‐Mannich bases, 3‐aroyl‐4‐aryl‐1‐phenethyl‐4‐piperidinols, 1b , 2b , 3b , 4b , 5b , 6b , 7b , 8b , 9b , were synthesized by a non‐classical Mannich reaction. The aryl part was: C₆H₅ for 1a , 1b ; 4‐CH₃C₆H₄ for 2a , 2b ; 4‐CH₃OC₆H₄ for 3a , 3b ; 4‐ClC₆H₄ for 4a , 4b ; 4‐FC₆H₄ for 5a , 5b ; 4‐BrC₆H₄ for 6a , 6b ; 2,4‐(Cl)₂C₆H₃ for 7a , 7b ; 4‐NO₂C₆H₄ for 8a , 8b ; and C₄H₃S(2‐yl) i. e., 2‐thienyl for 9a , 9b . Piperidinol compounds 2b , 3b , 4b , 5b , 7b , 8b , and 9b are reported here for the first time. The synthesized compounds were tested against seven types of plant pathogenic fungi and three types of human pathogenic fungi using the agar dilution assay. Itraconazole was tested against Candida parapsilosis as the reference compound, while Nystatin was tested as the reference compound against the other fungi. Compounds 1a , 1b , 2a , 4a , 4b , 5a , 5b , 6a , 7a , 8a , 9a , and 9b can be selected as model compounds to develop new antifungal agents against the human pathogen Microsporum canis. Compounds 8a and 8b , which had a similar antifungal activity compared with the reference compound Nystatin against the plant pathogen Aspergillus flavus, can serve as model compounds to develop new antifungal agents to solve agricultural problems.     

Age‐Related Alteration in Hepatic Disposition of the Neurotoxin 1‐Methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine and Pesticides

Abstract: Idiopathic Parkinson's disease may be caused by environmental neurotoxins such as pesticides, however the major risk factor is old age. We postulated that the high incidence of Parkinson's disease in older people is secondary to age‐related impairment of the hepatic detoxification of xenobiotics. Previously, we have shown that there are significant differences between the hepatic disposition of the neurotoxin 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP) and pesticides. Here, we investigated whether there are age‐related differences in the hepatic disposition of MPTP and pesticides, putatively associated with the pathogenesis of Parkinson's disease. We measured the hepatic disposition of paraquat, dichlorodiphenyltrichloroethane (DDT), malathion and MPTP using the multiple indicator dilution technique in the perfused livers of Fischer F344 rats aged 3 and 18 months. The recoveries of MPTP, DDT and malathion were increased from the livers of the older rats (by 258%, 253% and 134% compared with young rats, respectively). The hepatic transport of DDT and malathion into hepatocytes was reduced with age suggesting that part of the impaired uptake of neurotoxins may be secondary to an age‐related barrier to influx. Ageing may increase risk of Parkinson's disease by altering hepatic detoxification and increasing systemic bioavailability of neurotoxins.     

Structure elucidation of the designer drug N‐(1‐amino‐3,3‐dimethyl‐1‐oxobutan‐2‐yl)‐1‐(5‐fluoropentyl)‐3‐(4‐fluorophenyl)‐pyrazole‐5‐carboxamide and the relevance of predicted 13C NMR shifts – a case study

The detailed structure elucidation process of the new cannabimimetic designer drug, N‐(1‐amino‐3,3‐dimethyl‐1‐oxobutan‐2‐yl)‐1‐(5‐fluoropentyl)‐3‐(4‐fluorophenyl)‐pyrazole‐5‐carboxamide, with a highly substituted pyrazole skeleton, using nuclear magnetic resonance (NMR) spectroscopic and mass spectrometric (MS) techniques is described. After a first analysis of the NMR spectra and comparison with 48 possible pyrazole and imidazole structures, a subset of six positional isomeric pyrazoles and six imidazoles remained conceivable. Four substituents of the heterocyclic skeleton were identified: a proton bound to a pyrazole ring carbon atom; a 5‐fluoropentyl group; a 4‐fluorophenyl substituent; and a carbamoyl group, which is N‐substituted with a methyl residue carrying a tert.‐butyl and a carbamoyl substituent. The 5‐fluoropentyl residue is situated at the nitrogen ring atom. Additional NMR experiments like the ¹H,¹³C HMBC were performed, but due to the small number of signals based on long‐range couplings, the comparison of predicted and observed ¹³C chemical shifts became necessary. The open access Internet shift prediction programs NMRDB, NMRSHIFTDB2, and CSEARCH were employed for the prediction of ¹³C shift values which allowed an efficient and unambiguous structure determination. For the identified N‐(1‐amino‐3,3‐dimethyl‐1‐oxobutan‐2‐yl)‐1‐(5‐fluoropentyl)‐3‐(4‐fluorophenyl)‐pyrazole‐5‐carboxamide, the best agreement between predicted ¹³C shifts and the observed chemical shifts and long‐range couplings for the pyrazole ring carbon atoms, with a standard error of about 2 ppm, was found with each of the predictions. For the comparison of measured and predicted chemical shifts model compounds with simple substituents proved helpful. The identified compound is a homologue of AZ‐037 which is offered by Internet suppliers. Copyright © 2015 John Wiley & Sons, Ltd.     

The synthesis of (S)‐di‐n‐propyl‐(8‐isoxazol‐5‐yl‐1,2,3,4‐tetrahydronaphthalen‐2‐yl)amine hydrochloride and its C‐14‐labeled isotopomer

The partial ergoline LY228729 (1) which was a potent 5HT_1A agonist has been studied clinically. Somewhat later, a related analog, (S)‐di‐n‐propyl‐(8‐isoxazol‐5‐yl‐1,2,3,4‐tetrahydronaphthalen‐2‐yl)amine (2a) which in addition to potent 5HT_1A agonist activity was a muscarinic antagonist, was chosen for clinical development for use in the treatment of irritable bowel syndrome. In the course of pre‐clinical evaluation of 2a , radiolabeled material was required for ADME studies. In this paper, we have discussed the preparation of 2a and 2b (the C‐14‐labeled isotopomer of 2a ). Copyright © 2005 John Wiley & Sons, Ltd.     

Synthesis and mycobacterial evaluation of 5‐substituted‐6‐acetyl‐2‐amino‐7‐methyl‐5,8‐dihydropyrido‐[2,3‐d]pyrimidin‐4(3H)‐one derivatives

5‐Substituted‐6‐acetyl‐2‐amino‐7‐methyl‐5,8‐dihydropyrido[2,3‐d]pyrimidin‐4(3H)‐one derivatives were synthesized and evaluated against Mycobacterium tuberculosis H37Rv, Mycobacterium aurum, Escherichia coli, and Staphylococcus aureus as well as a human monocyte‐derived macrophage (THP‐1), and murine macrophage (RAW 264.7) cell lines to assess their antibacterial and cytotoxic potential, respectively. The compounds showed activity in the range of 1.95–125 µg/ml against M. tuberculosis but showed no activity against M. aurum, E. coli, and S. aureus, indicating selectivity towards slow‐growing mycobacterial pathogens. The compounds exhibited very low to no cytotoxicity up to 500 µg/ml concentration against eukaryotic cell lines. The most potent molecule, 2l , showed a minimum inhibitory concentration of 1.95 µg/ml against M. tuberculosis H37Rv and a selectivity index of >250 against both the eukaryotic cell lines. Furthermore, 2l showed moderate inhibition of whole‐cell mycobacterial drug‐efflux pumps when compared to verapamil, a known potent inhibitor of efflux pumps. Thus, derivative 2l was identified as an antituberculosis hit molecule, which could be used to yield more potent lead molecules.     

Preparation of 1,2,3,4,6‐penta‐O‐galloyl‐[U‐14C]‐D‐glucopyranose

The synthesis of 1,2,3,4,6‐penta‐O‐galloyl‐[U‐¹⁴C]‐D‐glucopyranose is described. [U‐¹⁴C] glucopyranose was reacted with tri‐O‐benzylgallic acid forming 1,2,3,4,6‐penta(tri‐O‐benzylgalloyl)‐[U‐¹⁴C]‐D‐glucopyranose as chromatograpically separable anomers. Removal of the benzyl group by catalytic hydrogenation afforded 1,2,3,4,6‐penta‐O‐galloyl‐[U‐¹⁴C]‐D‐glucopyranose in 54% overall yield. Copyright © 2002 John Wiley & Sons, Ltd.     

Synthesis of the perdeuterated cellulose solvents 1‐ethyl‐3‐methylimidazolium acetate (EMIM‐OAc‐d14) and 1‐butyl‐3‐methylimidazolium acetate (BMIM‐OAc‐d18) and of 2‐13C‐butyl‐3‐methylimidazolium acetate

The syntheses of two perdeuterated ionic liquids (ILs), which have found use as solvents for cellulose derivatization and processing in addition, are described: 1‐ethyl‐3‐methylimidazolium acetate (EMIM‐OAc‐d₁₄) and 1‐butyl–3‐methylimidazolium acetate (BMIM‐OAc‐d₁₈). The targets were obtained from imidazole in three‐step sequences starting with butylation and ethylation, respectively. The resulting 1‐alkyl imidazoles were purified, and subsequently methylated according to a novel protocol using dimethylcarbonate‐d₆. To obtain the 1‐alkyl‐3‐methylimidazolium moiety, methylation of 1‐alkylimidazoles proved to be superior to the conventional approach of alkylating 1‐methylimidazole. Addition of acetic acid‐d₄ caused traceless degradation of the methylcarbonate counter anions, which were neatly exchanged for acetate. The IL 2‐¹³C‐butyl‐3‐methylimidazolium acetate, in which the isotopically enriched C‐2 is a good NMR‐indicator of side reactions and solvent–solute interactions, was synthesized according to the same reaction sequence, starting from 2‐¹³C‐1‐alkylimidazole which, in turn, was obtained by reaction of glyoxale, alkylamine, ammonia and paraformaldehyde‐¹³C. Copyright © 2009 John Wiley & Sons, Ltd.     

Synthesis and characterization of tritium labeled N‐((R)‐1‐((S)‐4‐(4‐chlorophenyl)‐4‐hydroxy‐3,3‐dimethylpiperidin‐1‐yl)‐3‐methyl‐1‐oxobutan‐2‐yl)‐3‐sulfamoylbenzamide

N‐((R)‐1‐((S)‐4‐(4‐chlorophenyl)‐4‐hydroxy‐3,3‐dimethylpiperidin‐1‐yl)‐3‐methyl‐1‐oxobutan‐2‐yl)‐3‐sulfamoylbenzamide is a potent C‐C chemokine receptor 1 (CCR1) antagonist. The compound, possessing benzamide functionality, successfully underwent tritium/hydrogen (T/H) exchange with an organoiridium catalyst (Crabtree's catalyst). The labeling pattern in the product was studied with liquid chromatography–mass spectrometry, time‐of‐flight mass spectrometry, and ³H‐NMR. Overall, multiple labeled species were identified. In addition to the anticipated incorporation of tritium in the benzamide moiety, tritium labeling was observed in the valine portion of the molecule including substitution at its chiral carbon. Using authentic standards, liquid chromatography analysis of the labeled compound showed complete retention of stereochemical configuration.     

Antithrombotic Activity of a Newly Synthesized Coumarin Derivative 3‐(5‐Hydroxy‐2,2‐dimethyl‐chroman‐6‐yl)‐N‐{2‐[3‐(5‐hydroxy‐2,2‐dimethyl‐chroman‐6‐yl)‐propionylamino]‐ethyl}‐propionamide

Anti‐platelet therapy is a useful strategy to prevent acute thromboembolic artery occlusions. This study was designed to assess the efficacy of seselin derivatives against murine pulmonary thromboembolism, bleeding time, platelet activation and thrombosis. Administration of C3 (16 mg/kg) offered 70% protection against collagen‐ and epinephrine‐induced pulmonary thromboembolism and 30% protection against arachidonic acid‐induced death in mice, without adversely affecting bleeding time. No significant difference was observed by C3 in ferric chloride‐induced arterial thrombosis in rats. Significant reduction in thrombus weight was observed in arteriovenous shunt model. In rat PRP, C3 reduced ADP and collagen‐induced platelet aggregation. In chronic hamster model of dyslipidemia, administration of C3 (16 mg/kg p.o. for 90 days) had no effect on plasma lipids, vasoreactivity and platelet adhesion. C3 fed hamsters showed reduced whole‐blood aggregation response to ADP and collagen compared to HC‐fed hamsters. In addition, C3 augmented thrombin time; however, time to occlusion was not increased. These results convincingly demonstrated that C3 is a novel molecule that reduces the risk of thrombosis and alleviates prothrombotic state associated with hyperlipidemia without any adverse effect on bleeding time. The high benefit/risk ratio of this compound makes it a suitable candidate for future valid studies.     

New biological investigations on 3‐bromophenyl 6‐acetoxymethyl‐2‐oxo‐2H‐1‐benzopyran‐3‐carboxylate as anti‐angiogenic agent

The development of blood vessels inside tumors is required to provide the nutrients and oxygen needed for tumor growth and to allow the spread of cancer cells at a distance to form metastasis. Angiogenesis is also implicated in ocular diseases like age‐related macular degeneration. The present work describes the potential anti‐angiogenic properties of a coumarinic derivative, 3‐bromophenyl 6‐acetoxymethyl‐2‐oxo‐2H‐1‐benzopyran‐3‐carboxylate (IK9), previously described as a potent inhibitor of HT 1080 fibrosarcoma cell invasion in vitro and tumor growth in vivo. In vivo, ex vivo, and in vitro models were used to delineate the anti‐angiogenic properties of IK9. The anti‐angiogenic effect of IK9 was demonstrated in vivo in a choroidal neovascularization mice model and additionally ex vivo in a rat aortic ring assay where it was more active than the known matrix metalloproteinase inhibitor Ro 28‐2653. IK9 did not affect apoptosis, proliferation, or endothelial cell invasiveness in vitro. These findings suggest a complex mechanism of action of the compound via direct or indirect effects on endothelial cell properties. This study identifies IK9 as a new potent inhibitor of angiogenesis and suggests its potential use as a therapeutic agent. Drug Dev Res 71, 2010. © 2010 Wiley‐Liss, Inc.     

Metabolism of the tryptamine‐derived new psychoactive substances 5‐MeO‐2‐Me‐DALT, 5‐MeO‐2‐Me‐ALCHT,and 5‐MeO‐2‐Me‐DIPT and their detectability in urine studied by GC–MS,LC–MSn,and LC‐HR‐MS/MS

Many N,N‐dialkylated tryptamines show psychoactive properties and were encountered as new psychoactive substances. The aims of the presented work were to study the phase I and II metabolism and the detectability in standard urine screening approaches (SUSA) of 5‐methoxy‐2‐methyl‐N,N‐diallyltryptamine (5‐MeO‐2‐Me‐DALT), 5‐methoxy‐2‐methyl‐N‐allyl‐N‐cyclohexyltryptamine (5‐MeO‐2‐Me‐ALCHT), and 5‐methoxy‐2‐methyl‐N,N‐diisopropyltryptamine (5‐MeO‐2‐Me‐DIPT) using gas chromatography–mass spectrometry (GC–MS), liquid chromatography coupled with multistage accurate mass spectrometry (LC–MSⁿ), and liquid chromatography‐high‐resolution tandem mass spectrometry (LC‐HR‐MS/MS). For metabolism studies, urine was collected over a 24 h period after administration of the compounds to male Wistar rats at 20 mg/kg body weight (BW). Phase I and II metabolites were identified after urine precipitation with acetonitrile by LC‐HR‐MS/MS. 5‐MeO‐2‐Me‐DALT (24 phase I and 12 phase II metabolites), 5‐MeO‐2‐Me‐ALCHT (24 phase I and 14 phase II metabolites), and 5‐MeO‐2‐Me‐DIPT (20 phase I and 11 phase II metabolites) were mainly metabolized by O‐demethylation, hydroxylation, N‐dealkylation, and combinations of them as well as by glucuronidation and sulfation of phase I metabolites. Incubations with mixtures of pooled human liver microsomes and cytosols (pHLM and pHLC) confirmed that the main metabolic reactions in humans and rats might be identical. Furthermore, initial CYP activity screenings revealed that CYP1A2, CYP2C19, CYP2D6, and CYP3A4 were involved in hydroxylation, CYP2C19 and CYP2D6 in O‐demethylation, and CYP2C19, CYP2D6, and CYP3A4 in N‐dealkylation. For SUSAs, GC–MS, LC‐MSⁿ, and LC‐HR‐MS/MS were applied to rat urine samples after 1 or 0.1 mg/kg BW doses, respectively. In contrast to the GC–MS SUSA, both LC–MS SUSAs were able to detect an intake of 5‐MeO‐2‐Me‐ALCHT and 5‐MeO‐2‐Me‐DIPT via their metabolites following 1 mg/kg BW administrations and 5‐MeO‐2‐Me‐DALT following 0.1 mg/kg BW dosage. Copyright © 2017 John Wiley & Sons, Ltd.     

Inhibition of 3‐hydroxy‐3‐methylglutaryl‐coenzyme A reductase increases the expression of interferon‐responsive genes

The 3‐hydroxy‐3‐methylglutaryl‐coenzyme A reductase (HMGCR) pathway is an important metabolic route that is present in almost every organism. However, whether HMGCR affects the expression of interferon (IFN)‐responsive genes is unclear. In the present study, expression levels of IFN‐responsive genes were monitored by real time polymerase chain reaction and enzyme‐linked immunosorbent assay. The results showed that expression levels of IFN‐responsive genes were significantly increased in HMGCR‐downregulated cells and HMGCR inhibitor‐treated cells, indicating that inhibition of HMGCR activates the expression of IFN‐responsive genes. The result in this study will provide new insight into the role of 3‐hydroxy‐3‐methylglutaryl‐coenzyme A reductase in antiviral research.     

4‐amino‐6‐alkyloxy‐2‐alkylthiopyrimidine derivatives as novel non‐nucleoside agonists for the adenosine A1 receptor

Three 4‐amino‐6‐alkyloxy‐2‐alkylthiopyrimidine derivatives ( 4 – 6 ) were investigated as potential non‐nucleoside agonists at human adenosine receptors (ARs). When tested in competition binding experiments, these compounds exhibited low micromolar affinity (K_i values comprised between 1.2 and 1.9 μm ) for the A₁ AR and no appreciable affinity for the A_2A and A₃ ARs. Evaluation of their efficacy profiles by measurement of intracellular cAMP levels revealed that 4 and 5 behave as non‐nucleoside agonists of the A₁ AR with EC₅₀ values of 0.47 and 0.87 μm , respectively. No clear concentration‐response curves could be instead obtained for 6 , probably because this compound modulates one or more additional targets, thus masking the putative effects exerted by its activation of A₁ AR. The three compounds were not able to modulate A_2B AR‐mediated cAMP accumulation induced by the non‐selective AR agonist NECA, thus demonstrating no affinity toward this receptor.     

Synthesis of 2H‐ and 3H‐labeled N‐cyclopropylmethyl‐7α‐[(R)‐1‐hydroxy‐1‐methyl‐3‐(2thienyl)‐propyl]‐6,14‐endoethano‐6,7,8,14‐tetrahydro nororipavine

A procedure for deuterium and tritium labeling of the titled compound, an analgesic agent, was developed. A secondary amine intermediate was acylated to an acylamide, then the carbonyl function was reduced by LiAlD₄ to yield the tertiary amine. In the tritium‐labeled synthesis, the process utilized a bromo‐substituted precursor, which was subsequently reduced with ³H₂ in the presence of a Pd/C catalyst. The labeled compounds were successfully applied in pharmacokinetic and pharmacological studies. Copyright © 2005 John Wiley & Sons, Ltd.