piperidines and triperiden

The effect of the virostatic norakin on various in vitro activities of influenza viruses was studied. The infectivity of the [A/PR/8/34 (H1N1)] strain for MDCK (Madin Darby canine kidney) cells was reduced by a factor of 10 with 10(-7) M norakin. At 10(-5) M, it was below 1% of the control value without norakin. At higher concentrations (> or = 10(-4) M), cytotoxic effects occurred. Neither hemolysis nor hemagglutination were affected by norakin concentrations up to 10(-4) M. An in vitro fluorescence dequenching assay was used to study the viral fusion activity in the presence and absence of norakin. Fusion between influenza viruses and virus receptor-containing liposomes was not significantly affected up to norakin concentrations of 10(-3) M. However, the intracellular pH in MDCK cells was raised from pH 5.3 (without norakin) to about pH 6 with 10(-5) M norakin. This parallels the pH dependence of PR8 viral activities like hemolysis and fusion. We therefore suggest that norakin does not interact directly with the viral hemagglutinin, but inhibits viral infection through increase of the internal pH in the prelysosomal compartment.

Topics: Animals; Antiviral Agents; Cells, Cultured; Dogs; Humans; Kidney; Orthomyxoviridae; Piperidines

Several novel tricyclic compounds with a unique amine moiety (1, 2a--i) were designed and prepared based on the structure of triperiden for the development of anti-influenza virus agents. An in vitro antiviral assay showed that 1-(1-azabicyclo[3.3.0]octan-5-yl)-1-(4-fluorophenyl)-1-(2-tricyclo[3.3.1.1(3.7)]decyl)methan-1-ol hydrochloride (2f) has a potent anti-influenza A virus activity. Furthermore, since 2f was well tolerated in mice, 2f is promising as a novel anti-influenza virus agent for humans.

Topics: Animals; Antiviral Agents; Cell Line; Cytopathogenic Effect, Viral; Humans; Influenza A virus; Male; Mice; Mice, Inbred BALB C; Piperidines; Ribavirin; Structure-Activity Relationship

Norakin-resistant (NR) mutants of fowl plague virus (A/FPV/Weybridge, H7N7) have 1 to 2 (in one instance 3) amino acid substitutions in different positions of the heavy (HA 1) and/or light (HA 2) subunits of the haemagglutinin (HA) molecule. Investigation of NR mutants using the haemagglutination inhibition test with monoclonal antibodies (MAb) to the HA of A/seal/Massachusetts/80 (H7N7) virus revealed that one of the mutants (NR 1) differs antigenically from the wild-type fowl plague virus: its haemagglutination was not inhibited by MAb 55/2 and 58/6. By contrast, MAb-resistant (escape) mutants, selected from the wild-type fowl plague virus under pressure from MAb 55/2 or 58/6, showed reduced drug sensitivity. These findings suggest a possibility of correlation between alteration of influenza virus antigenicity and change of its sensitivity to drugs whose target is the haemagglutinin. This potential effect should be taken into account when antiviral substances directed to surface influenza virus antigens are being developed for use as antiviral drugs.

Topics: Amino Acid Sequence; Animals; Antibodies, Monoclonal; Birds; Chick Embryo; Drug Resistance, Microbial; Epitopes; Hemagglutinin Glycoproteins, Influenza Virus; Hemagglutinins, Viral; Influenza A virus; Influenza in Birds; Molecular Sequence Data; Mutation; Piperidines

To elucidate the mode of action of norakin against influenza A virus we sequenced the hemagglutinin gene of 11 norakin-resistant mutants. Resistance was coupled with 1-3 amino acid exchanges. The majority of mutations was localized in the HA2 polypeptide and was mostly associated with changes in charge or polarity of the amino acids. The amino acid substitutions are discussed in the context of the 3D structure of X31 hemagglutinin considered to be representative of the influenza hemagglutinins. Most of the mutations appear to destabilize the pH 7.0 structure by distorting or destroying hydrogen bonds as well as salt-bridges which are responsible for intra- and intersubunit contacts, while others destabilize the location of the fusion peptide, facilitating conformational changes in the presence of the inhibitor.

Topics: Amino Acids; Animals; Antiviral Agents; Chick Embryo; Chromosome Mapping; Drug Resistance, Microbial; Hemagglutinins; Influenza A virus; Mutation; Piperidines; Protein Conformation; RNA, Viral

Norakin at 1 microgram/ml inhibits the reproduction of respiratory syncytial virus (RSV) in Vero cells to 50% and at 5 micrograms/ml to 90%. The development of lung lesions in RSV-infected BALB/c mice was suppressed by 70% when the animals were treated with two doses (25 mg/kg each) of norakin, 30 min before and 4 hr post infection. (p.i.), respectively.

Topics: Animals; Antiviral Agents; Dose-Response Relationship, Drug; Female; Mice; Mice, Inbred BALB C; Piperidines; Pneumonia, Viral; Respiratory Syncytial Viruses; Respirovirus Infections; Vero Cells; Virus Replication

The nucleotide sequences of the hemagglutinin genes of four norakin-resistant mutants of Influenza A/FPV/Weybridge were determined and compared to the wild-type hemagglutinin. All mutants show one or two amino acid substitutions which are discussed to destabilise the pH 7 conformation of hemagglutinin.

Topics: Amino Acid Sequence; Drug Resistance, Microbial; Genes, Viral; Hemagglutinins, Viral; Influenza A virus; Piperidines; Structure-Activity Relationship

After oral application of triperiden (1; Norakin) to male Wistar rats besides the unchanged isomers of 1 (1a and 1b, respectively [3]) six hydroxy metabolites and an artifact were isolated from urine and also identified in faeces. All metabolites are hydroxy derivatives of the piperidine and the tricyclic moieties of the molecule 1a. No hydroxylation of the phenyl ring was observed. 10-20% of the metabolites were sulfate and/or glucuronide conjugates. Main metabolites were 2 and 3 (greater than 50% of the total excretion products). About 70% of 1a, 1b and metabolites were excreted with the urine. The in vivo metabolites also could be identified in the 9000 g supernatant of rat and human liver homogenates.

Topics: Animals; Biotransformation; Feces; Humans; In Vitro Techniques; Liver; Male; Parasympatholytics; Piperidines; Rats; Rats, Inbred Strains

The antiparkinsonian triperiden (1; as hydrochloride Norakin) is a mixture of the stereoisomers 1a and 1b. Their identification and separation by chromatographic methods or fractional crystallisation of the tartrates is described. By means of IR- und 13C-NMR spectral data structures of 1a and 1b are proposed. Under proton catalysis 1b racemizes to 1a. In acidic solution (heating in 0.1 mol.1-1 HCl or storage in gastric juice at 37 degrees C) hydrolysis of 1 takes place and four isomeric products were observed (Z1-Z4), which arise by cleavage of the cyclopropyl moiety. The main product Z2 was identified as the 2"-hydroxy derivative. The solid drug is stable at least for 5 years.

Topics: Antiparkinson Agents; Chemical Phenomena; Chemistry; Chromatography, High Pressure Liquid; Crystallization; Drug Stability; Magnetic Resonance Spectroscopy; Piperidines; Spectrophotometry, Infrared; Spectrophotometry, Ultraviolet; Stereoisomerism

The anticholinergic anti-parkinsonism drug Norakin is an inhibitor of influenza virus multiplication. By crossing a Norakin-resistant variant of fowl plague virus (FPV) strain Weybridge with the sensitive FPV/Rostock/34 wild-type virus, Norakin-resistant recombinants were obtained. Analyses of the gene composition showed that all Norakin-resistant recombinants had inherited their haemagglutinin gene from the Norakin-resistant parent strain. The majority of the recombinants had received all the other gene segments from the sensitive parent strain. Norakin was shown to inhibit red blood cell lysis induced either by purified virions or by the haemagglutinin of a sensitive FPV strain at low pH, but failed to affect the Norakin-resistant FPV variant. No aggregation of autoliposomes containing the haemagglutinin of a sensitive FPV strain or digestion of the HA1 subunit of haemagglutinin by trypsin occurred in the presence of Norakin at acid pH. The data suggest that the haemagglutinin of FPV is the target for the antiviral activity of Norakin, which acts by inhibiting the conformational change in the haemagglutinin at acid pH important for lysis.

Topics: Animals; Cells, Cultured; Chick Embryo; Drug Resistance, Microbial; Genes, Viral; Hemagglutination; Hemagglutinins, Viral; Hemolysis; Hydrogen-Ion Concentration; In Vitro Techniques; Influenza A virus; Liposomes; Membrane Fusion; Piperidines; Recombination, Genetic; Trypsin; Virus Replication

Topics: Animals; Antiparkinson Agents; Benzilates; Drug Interactions; In Vitro Techniques; Microsomes, Liver; Mixed Function Oxygenases; Phenobarbital; Piperidines; Rats

The action of the anticholinergic drug Norakin (triperiden) on the reproduction of influenza virus A and B strains was studied. In cell culture, primary transcription of influenza A/FPV/Weybridge and of influenza B/Japan/73 is strongly inhibited by Norakin (20 micrograms/ml). When present simultaneously, Norakin and rimantadine exert an additive effect. Rimantadine-resistant mutants of influenza A exhibit a definite, though limited, cross-resistance to Norakin, and vice versa. The results indicate that Norakin blocks early stages of the infectious cycle and that the modes of antiviral action of Norakin and rimantadine are not identical.

Topics: Animals; Cells, Cultured; Chick Embryo; Influenza A virus; Influenza B virus; Parasympatholytics; Piperidines; Rimantadine; RNA; RNA, Complementary; Transcription, Genetic

Topics: Amantadine; Animals; Antiviral Agents; Biperiden; Cell Line; Chick Embryo; Drug Interactions; Drug Resistance, Microbial; Genes, Viral; Hemagglutination, Viral; Hemolysis; Influenza A virus; Interferon Type I; Interferons; Measles virus; Mutation; Piperidines; Virus Replication

Intranasal (i. n.) infection with 10 LD50 of Sindbis virus caused acute encephalomyelitis and death in ABD2F1 mice 3-7 days post infection (p.i.). Histologic lesions were found in the CNS, pancreas. liver, parotid glands, exorbital lacrimal glands, lymphoid organs and kidneys. Repeated oral administration of the anticholinergic anti-Parkinson drug Norakin protected infected animals from death in a dose-dependent manner when treatment was started prior to but not after virus inoculation. The maximum protective effect was achieved when the drug was administered twice daily at doses of 2.5 or 5.0 mg/kg body mass for at least 56 hr; single injections of the full daily dose were ineffective. Daily doses of greater than or equal to 25 mg/kg body mass had a reduced protective effect or failed to prevent mortality. Administration of Norakin up to doses of 300 mg/kg body mass per day to noninfected ABD2F1 mice were tolerated without obvious clinical or histological signs of illness over a period of 104 hr. Replication of sindbis virus in BHK 21/C13 cells was not inhibited by Norakin concentrations up to 10 micrograms/ml. In Mengo virus-infected mice Norakin did not exert any protective effect within the range of 1.25-50.0 mg/kg body mass when treatment started 1 hr before infection and has been continued twice daily over a period of 104 hr.

Topics: Animals; Antiparkinson Agents; Antiviral Agents; Cells, Cultured; Cricetinae; Enterovirus Infections; Mengovirus; Mice; Piperidines; Sindbis Virus; Togaviridae Infections; Virus Replication