ABSTRACT
SAR investigations of the 4- and 5-positions of a series of 4-amino-4H-pyran-2-carboxylic acid 6-carboxamides are reported. Potent inhibitors of influenza A sialidase with marked selectivity over the influenza B enzyme were obtained when the basic 4-amino substituent was replaced by hydroxyl or even deleted. Modifications at the 5-position exhibited a tight steric requirement, with trifluoroacetamide being optimal.
Subject(s)
Antiviral Agents/chemistry , Enzyme Inhibitors/chemistry , Nylons/chemistry , Pyrans/chemistry , Sialic Acids/chemistry , Antiviral Agents/chemical synthesis , Antiviral Agents/pharmacology , Binding Sites , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Guanidines , Influenza A virus/drug effects , Influenza A virus/enzymology , Influenza B virus/drug effects , Influenza B virus/enzymology , Models, Molecular , Molecular Structure , Neuraminidase/antagonists & inhibitors , Neuraminidase/metabolism , Nylons/pharmacology , Pyrans/pharmacology , Sialic Acids/metabolism , Structure-Activity Relationship , Viral Plaque Assay , ZanamivirABSTRACT
Recombinant fusion proteins containing human atrial natriuretic factor, ANF(1-28) joined to chloramphenicol acetyltransferase (CAT) via cleavable linker sequences have been produced in Escherichia coli. The linker sequences were designed to allow the release of authentic ANF(1-28) following proteolytic cleavage by enterokinase or thrombin, or chemical cleavage with 2-(2-nitrophenylsulphenyl)-3-methyl-3'-bromoindolenine. Proteins, containing ANF(1-28) fused to the carboxyl-terminal region of CAT (using the ScaI restriction site in the cat gene), were largely soluble in E. coli and were obtained in higher yield than analogues containing ANF(1-28) linked to shorter CAT sequences. The longer derivatives also retained CAT activity allowing subsequent purification by affinity chromatography.
Subject(s)
Acetyltransferases/isolation & purification , Atrial Natriuretic Factor/biosynthesis , Escherichia coli/enzymology , Gene Expression Regulation , Recombinant Fusion Proteins/isolation & purification , Recombinant Proteins/isolation & purification , Amino Acid Sequence , Atrial Natriuretic Factor/genetics , Atrial Natriuretic Factor/isolation & purification , Base Sequence , Chloramphenicol O-Acetyltransferase , Enteropeptidase/metabolism , Escherichia coli/metabolism , Genetic Vectors , Hydrolysis , Molecular Sequence Data , Plasmids , Skatole/analogs & derivatives , Thrombin/metabolism , Transcription, GeneticABSTRACT
Anion exchange HPLC purification of synthetic oligonucleotides with a high guanosine content is difficult. This study has demonstrated that these sequences can be successfully purified by anion exchange HPLC using standard conditions provided that the base protecting groups (isobutyryl[ib] and benzoyl[bz]) are retained on the otherwise deprotected oligomer.
Subject(s)
Guanosine , Oligodeoxyribonucleotides/isolation & purification , Chromatography, High Pressure Liquid/methods , Chromatography, Ion Exchange/methods , Indicators and ReagentsABSTRACT
With the aim of finding an antidysrhythmic agent suitable for intravenous or oral administration we have examined a range of steroids carrying basic substituents. The primary screen involved control of cardiac dysrhythmias induced by intravenous infusion of aconitine into pentobarbitone-anaesthetised artificially-respired rats. The best activity was found among a series of 11 alpha-alkylamino steroids and structure-activity studies included modification of the alkylamino group and variation of substituents in ring A and at the 17-position. Good oral and intravenous activity was found among 17 beta-methoxycarbonyl-5 alpha-androstanes and methyl 2 beta-ethoxy-3 alpha-hydroxy-11 alpha-(3-methylbutylamino)-5 alpha-androstane-17 beta-carboxylate hydrochloride (CCI 22277) was selected for more detailed pharmacological study.
