ABSTRACT
Introduction: Biofilm-associated infections persist as a therapeutic challenge in contemporary medicine. The efficacy of antibiotic therapies is ineffective in numerous instances, necessitating a heightened focus on exploring novel anti-biofilm medical strategies. Among these, iminosugars emerge as a distinctive class of compounds displaying promising biofilm inhibition properties. Methods: This study employs an in vivo wound infection mouse model to evaluate the effectiveness of PDIA in treating biofilm-associated skin wound infections caused by Staphylococcus aureus and Pseudomonas aeruginosa. Dermic wounds in mice were infected with biofilm-forming strains, specifically S. aureus 48 and P. aeruginosa 5, which were isolated from patients with diabetic foot, and are well-known for their strong biofilm formation. The subsequent analysis included clinical, microbiological, and histopathological parameters. Furthermore, an exploration into the susceptibility of the infectious strains to hydrogen peroxide was conducted, acknowledging its potential presence during induced inflammation in mouse dermal wounds within an in vivo model. Results: The findings revealed the efficacy of PDIA iminosugar against the S. aureus strain, evidenced by a reduction in bacterial numbers within the wound and the inflammatory focus. Discussion: This study suggests that PDIA iminosugar emerges as an active and potentially effective antibiofilm agent, positioning it as a viable treatment option for staphylococcal infections.
Subject(s)
Anti-Bacterial Agents , Biofilms , Disease Models, Animal , Pseudomonas Infections , Pseudomonas aeruginosa , Staphylococcal Infections , Staphylococcus aureus , Animals , Pseudomonas aeruginosa/drug effects , Staphylococcus aureus/drug effects , Mice , Biofilms/drug effects , Biofilms/growth & development , Pseudomonas Infections/microbiology , Pseudomonas Infections/drug therapy , Staphylococcal Infections/microbiology , Staphylococcal Infections/drug therapy , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Wound Infection/microbiology , Wound Infection/drug therapy , Humans , FemaleABSTRACT
An innovative, concise synthesis of the aminocyclopentenediol fragment of queuosine is reported. The synthesis is based on the stereocontrolled addition of a vinylGrignard·LiCl reagent to a t-butanesulfinyl L-ribofuranosylamine, followed by dehydrodeoxygenation to generate a second vinyl group and ring-closing metathesis to form the five-membered ring scaffold of the natural product. This approach has the potential for the development of a larger scale synthesis.
ABSTRACT
We report here a new method for the stereoselective synthesis of five-membered iminosugar C-glycosides using an intramolecular palladium-catalyzed carboamination. We have prepared efficiently two sugar-derived aminoalkenes, which were submitted to the carboamination conditions in the presence of different aryl bromides. A small library of protected iminosugars carrying a 1-C-arylmethyl substituent was obtained, and some of them were fully deprotected to yield original iminosugar C-glycosides. This methodology provides one of the shortest pathways to this family of molecules.
Subject(s)
Glycosides , Palladium , Amination , Catalysis , StereoisomerismABSTRACT
Many difficult-to-treat human infections related to catheters and other indwelling devices are caused by bacteria residing in biofilms. One of the key properties of microorganisms residing in a biofilm is decreased susceptibility towards antimicrobial agents. Therefore, many different approaches have been researched to destroy or inhibit biofilm production by bacteria. Different iminosugars (IS) were reported to inhibit biofilm formation in S. mutans, S. aureus, and P. aeruginosa. The aim of this study was to look for a spectrum of the activity in one of these IS. The iminosugar PDIA beta-1-C-propyl-1,4-dideoxy-1,4-imino-L-arabinitol was tested in vitro at the same concentration against 30 different strains of the most important Gram-negative and Gram-positive human pathogens looking for their biofilm production and viability at different time intervals. It appeared that PDIA inhibited biofilm production of Enterobacter spp., P. aeruginosa, Enterococcus spp. and S. aureus in 8 h, and Klebsiella spp., Acinetobacter spp. and S.epidermidis in 24 h. PDIA caused no growth inhibition of the tested bacteria at a concentration of 0.9 mM. Our results indicate a broad-spectrum biofilm inhibitory activity of PDIA. which may be the basis for future application studies that will help in control of the associated device and biofilm-related infections caused by a wide spectrum of the causative agents.
ABSTRACT
In this note, an hydrozirconation/bromination/Michaelis-Arbuzov sequence was developped to introduce a trimethylene phosphonate unit on ketopyranosides. Performed on polyfunctional substrates bearing orthogonal protecting groups, this new approach provided a straightforward entry towards a large diversity of glycophosphomimetics having a quaternary anomeric position.
Subject(s)
Organophosphorus Compounds/chemical synthesis , Carbohydrates/chemistry , Glycosylation , Halogenation , Ketones/chemistry , Molecular Structure , Organophosphorus Compounds/chemistryABSTRACT
(5aR)-5a-C-pentyl-4-epi-isofagomine 1 is a powerful inhibitor of lysosomal ß-galactosidase and a remarkable chaperone for mutations associated with GM1-gangliosidosis and Morquio disease type B. We report herein an improved synthesis of this compound and analogs (5a-C-methyl, pentyl, nonyl and phenylethyl derivatives), and a crystal structure of a synthetic intermediate that confirms its configuration resulting from the addition of a Grignard reagent. These compounds were evaluated as glycosidase inhibitors and their potential as chaperones for mutant lysosomal galactosidases determined. Based on these results and on docking studies, the 5-C-pentyl derivative 1 was selected as the optimal structure for further investigations: this compound induces the maturation of mutated ß-galactosidase in fibroblasts of a GM1-gangliosidosis patient and promote the decrease of keratan sulfate and oligosaccharide load in patient cells. Compound 1 is clearly capable of restoring ß-galactosidase activity and of promoting maturation of the protein, which should result in significant clinical benefit. These properties strongly support the development of compound 1 for the treatment of GM1-gangliosidosis and Morquio disease type B patients harboring ß-galactosidase mutations sensitive to pharmacological chaperoning.
Subject(s)
Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Gangliosidosis, GM1/drug therapy , Imino Pyranoses/chemistry , Imino Pyranoses/pharmacology , Mucopolysaccharidosis IV/drug therapy , beta-Galactosidase/antagonists & inhibitors , Drug Discovery , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/therapeutic use , Gangliosidosis, GM1/enzymology , Gangliosidosis, GM1/genetics , Gangliosidosis, GM1/metabolism , Humans , Imino Pyranoses/chemical synthesis , Imino Pyranoses/therapeutic use , Molecular Docking Simulation , Mucopolysaccharidosis IV/enzymology , Mucopolysaccharidosis IV/genetics , Mucopolysaccharidosis IV/metabolism , Mutation/drug effects , Structure-Activity Relationship , beta-Galactosidase/genetics , beta-Galactosidase/metabolismABSTRACT
This report is about the identification, synthesis and initial biological characterization of derivatives of 4-epi-isofagomine as pharmacological chaperones (PC) for human lysosomal ß-galactosidase. The two epimers of 4-epi-isofagomine carrying a pentyl group at C-5a, namely (5aR)- and (5aS)-5a-C-pentyl-4-epi-isofagomine, were prepared by an innovative procedure involving in the key step the addition of nitrohexane to a keto-pentopyranoside. Both epimers were evaluated as inhibitors of the human ß-galactosidase: the (5aR)-stereoisomer (compound 1) was found to be a very potent inhibitor of the enzyme (IC50 = 8 nM, 30× more potent than 4-epi-isofagomine at pH 7.3) with a high selectivity for this glycosidase whereas the (5aS) epimer was a much weaker inhibitor. In addition, compound 1 showed a remarkable activity as a PC. It significantly enhanced the residual activity of mutant ß-galactosidase in 15 patient cell lines out of 23, with enhancement factors greater than 3.5 in 10 cell lines and activity restoration up to 91% of normal. Altogether, these results indicated that (5aR)-5a-C-pentyl-4-epi-isofagomine constitutes a promising PC-based drug candidate for the treatment of GM1-gangliosidosis and Morquio disease type B.
Subject(s)
Enzyme Inhibitors/pharmacology , Gangliosidosis, GM1/genetics , Imino Pyranoses/pharmacology , Lysosomes/enzymology , Mucopolysaccharidosis IV/genetics , Mutation , beta-Galactosidase/antagonists & inhibitors , Drug Design , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Fibroblasts/drug effects , Gangliosidosis, GM1/enzymology , Gangliosidosis, GM1/pathology , Hot Temperature , Humans , Hydrogen-Ion Concentration , Imino Pyranoses/chemical synthesis , Imino Pyranoses/chemistry , Mucopolysaccharidosis IV/enzymology , Mucopolysaccharidosis IV/pathology , Protein Denaturation , beta-Galactosidase/chemistry , beta-Galactosidase/genetics , beta-Galactosidase/metabolismABSTRACT
A lack of an effective way to eliminate pathogenic bacteria hidden in the biofilm is a major problem in the treatment of chronic bacterial infections. Iminosugar derivatives are potential candidates for inhibitors of enzymes taking part in the biosynthesis of exopolysaccharides, which are forming bacterial biofilm. Investigated iminosugars were studied either at an early stage of biofilm formation or later on when the mature biofilm of Pseudomonas aeruginosa was already formed. A series of diverse iminosugar structures significantly inhibited biofilm formation, whereas they showed no influence on already formed biofilm. This indicates a possible mechanism of their action based on inhibition of exopolysaccharide backbone synthesis in the early stages of biofilm formation. Moreover, iminosugar derivatives did not show significant effect on the viable bacterial numbers in both early and mature biofilm forms. Importantly, they were not cytotoxic against human Caco-2 cells in vitro, which may be to their advantage in case of their medical application in preventing P. aeruginosa biofilm formation.
Subject(s)
Anti-Bacterial Agents/pharmacology , Biofilms/drug effects , Imino Sugars/pharmacology , Polysaccharides, Bacterial/antagonists & inhibitors , Pseudomonas aeruginosa/drug effects , Anti-Bacterial Agents/chemistry , Biofilms/growth & development , Caco-2 Cells , Cell Survival/drug effects , Colony Count, Microbial , Humans , Imino Sugars/chemistry , Microbial Viability/drug effects , Polysaccharides, Bacterial/biosynthesis , Pseudomonas aeruginosa/growth & development , Pseudomonas aeruginosa/metabolism , Species Specificity , Structure-Activity RelationshipABSTRACT
A series of 1,5-dideoxy-1,5-imino-(l)-ribitol (DIR) derivatives carrying alkyl or functionalized alkyl groups were prepared and investigated as glycosidase inhibitors. These compounds were designed as simplified 4-epi-isofagomine (4-epi-IFG) mimics and were expected to behave as selective inhibitors of ß-galactosidases. All compounds were indeed found to be highly selective for ß-galactosidases versus α-glycosidases, as they generally did not inhibit coffee bean α-galactosidase or other α-glycosidases. Some compounds were also found to be inhibitors of almond ß-glucosidase. The N-alkyl DIR derivatives were only modest inhibitors of bovine ß-galactosidase, with IC50 values in the 30-700 µM range. Likewise, imino-L-ribitol substituted at the C1 position was found to be a weak inhibitor of this enzyme. In contrast, alkyl substitution at C5 resulted in enhanced ß-galactosidase inhibitory activity by a factor of up to 1000, with at least six carbon atoms in the alkyl substituent. Remarkably, the 'pseudo-anomeric' configuration in this series does not appear to play a role. Human lysosomal ß-galactosidase from leukocyte lysate was, however, poorly inhibited by all iminoribitol derivatives tested (IC50 values in the 100 µM range), while 4-epi-IFG was a good inhibitor of this enzyme. Two compounds were evaluated as pharmacological chaperones for a GM1-gangliosidosis cell line (R301Q mutation) and were found to enhance the mutant enzyme activity by factors up to 2.7-fold.
Subject(s)
Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Galactosidases/antagonists & inhibitors , Ribitol/analogs & derivatives , Ribitol/pharmacology , Animals , Cattle , Dose-Response Relationship, Drug , Enzyme Inhibitors/chemical synthesis , Galactosidases/metabolism , Humans , Lysosomes/enzymology , Molecular Conformation , Ribitol/chemistry , Structure-Activity RelationshipABSTRACT
To further extend the scope of iminosugar biological activity, a systematic structure-activity relationship investigation has been performed by synthesizing and evaluating as cholinesterase inhibitors a library of twenty-three iminoalditols with different substitutions and stereochemistry patterns. These compounds have been evaluated in vitro for the inhibition of cholinesterases (different sources of acetylcholinesterase and butyrylcholinesterase). Some compounds have IC50 values in the micromolar range and display significant inhibition selectivity for butyrylcholinesterase over acetylcholinesterase. These are the first examples of iminosugar-based inhibitors of cholinesterases.
Subject(s)
Cholinesterase Inhibitors/chemistry , Imino Sugars/chemistry , Imino Sugars/pharmacology , Cholinesterase Inhibitors/pharmacology , Structure-Activity RelationshipABSTRACT
Several families of iminosugar-based galactoside mimics were designed, synthesized, and evaluated as galactocerebrosidase (GALC) inhibitors. They were also tested as inhibitors of lysosomal ß- and α-galactosidases in order to find new potent and selective pharmacological chaperones for treatment of the lysosomal storage disorder, Krabbe disease. Whereas 1-C-alkyl imino-L-arabinitols are totally inactive toward the three enzymes, 1-C-alkyl imino-D-galactitols were found to be active only toward α-galactosidase A. Finally, 1-N-iminosugars provided the best results, as 4-epi-isofagomine was found to be a good inhibitor of both lysosomal ß-galactosidase and GALC. Further elaboration of this structure is required to achieve selectivity between these two galactosidases.
Subject(s)
Galactosides/chemistry , Galactosylceramidase/antagonists & inhibitors , Imino Sugars/chemistry , alpha-Galactosidase/antagonists & inhibitors , beta-Galactosidase/antagonists & inhibitors , Galactosylceramidase/metabolism , Humans , Imino Pyranoses/antagonists & inhibitors , Imino Pyranoses/metabolism , Imino Sugars/metabolism , Imino Sugars/therapeutic use , Leukodystrophy, Globoid Cell/drug therapy , Lysosomes/enzymology , Protein Binding , Structure-Activity Relationship , alpha-Galactosidase/metabolism , beta-Galactosidase/metabolismABSTRACT
A series of iminoxylitol derivatives carrying a C-linked di-O-acyl or di-O-alkyl glyceryl substituent were prepared and characterized. All of these compounds, which were designed as glucosylceramide (GlcCer) mimics, were nanomolar inhibitors of lysosomal ß-glucosidase (glucocerebrosidase, GCase). Two of these pseudoglycolipids were further evaluated for their ability to enhance the activity of mutant GCase in human Gaucher cells. Although the di-O-hexyl ether was surprisingly devoid of chaperoning activity on both N370S and L444P GCases, the di-O-decanoyl ester was a potent chaperone of the L444P hydrolase, capable of increasing the residual activity of the enzyme by a factor of two at a very low concentration (50â nM); such a significant effect on the L444P mutation in human fibroblasts has not yet been observed. In heat-stress studies, the diether was found to be much more effective in stabilizing the wild-type enzyme than the diester. Four representative pseudoglycolipids were also assayed as inhibitors of GlcCer synthase, because such compounds could find use in the substrate reduction therapy approach to treat lysosomal storage diseases, but these compounds revealed only moderate activity. As efficient pharmacological chaperones, new structures such as the di-C10 -ester constitute leads for the development of therapeutic agents for typesâ 2 and 3 Gaucher disease, the most severe neuronopathic forms of this lysosomal disease.
Subject(s)
Biomimetics , Glucosylceramidase/antagonists & inhibitors , Glucosylceramides/chemistry , Molecular Chaperones/chemistry , Carbohydrate Sequence , Cell Line , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Fibroblasts/drug effects , Gaucher Disease/enzymology , Gaucher Disease/genetics , Glucosylceramides/pharmacology , Humans , Molecular Chaperones/pharmacology , MutationABSTRACT
Mono- and di-O-isopropylidene-l-sorbofuranose derivatives are important starting materials for the synthesis of modified sugars and useful chiral compounds. However, several inconsistencies in the spectral data of these compounds and erroneous structural assignments have been noted in the literature. The unambiguous synthesis of 1,2:4,6-di-O-isopropylidene-α-L-sorbofuranose and derivatives of 1,2- and 2,3-O-isopropylidene-α-L-sorbofuranoses has been achieved and definitive spectral data on these compounds are provided.
Subject(s)
Carbohydrates/chemistry , Carbohydrates/chemical synthesis , Sorbose/analogs & derivatives , Chemistry Techniques, Synthetic , Sorbose/chemical synthesis , Sorbose/chemistry , Spectrum AnalysisABSTRACT
A series of O-alkyl iminoxylitol derivatives was synthesized and evaluated as ß-glucocerebrosidase (GCase) inhibitors. This structure-activity study shows a dramatic influence of the position of the alkyl chain (α-C1, O2, O3, or O4) on human GCase inhibition. Remarkably, 1,2-shift of the alkyl chain from C1 to O2 was found to maintain high inhibitory potency toward GCase as well as chaperone activity at sub-inhibitory concentration (10â nM). Removal of the stereogenic center at the pseudo-anomeric position led to shorter and more practical synthetic sequences. 2-O-Alkyl iminoxylitol derivatives constitute a new promising class of leads for the treatment of Gaucher disease by means of pharmacological chaperone therapy.
Subject(s)
Gaucher Disease/drug therapy , Xylitol/therapeutic use , Chromatography, Liquid , Humans , Stereoisomerism , Xylitol/chemistryABSTRACT
A short synthesis of new beta-1-C-alkyl-1,5-dideoxy-1,5-imino-l-iditols by means of the diastereoselective addition of Grignard reagents onto a glucopyranosylamine is described. These compounds were evaluated as beta-glucocerebrosidase inhibitors and their activity was compared with that of related iminosugar derivatives in the d-gluco and d-xylo series. The results allowed us to conclude on the influence of the hydroxymethyl moiety and of the piperidine-ring conformation on the inhibitory activity.
Subject(s)
Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Glucosylceramidase/antagonists & inhibitors , Sugar Alcohols/chemical synthesis , Sugar Alcohols/pharmacology , Alkylation , Humans , Indicators and Reagents , Kinetics , Models, Molecular , Molecular Conformation , Recombinant Proteins/chemistry , Spectrometry, Fluorescence , StereoisomerismABSTRACT
The 1.6 A resolution structure of the micromolar competitive inhibitor S-(N,N-dimethylaminoethyl) phenylacetothiohydroximate-O-sulfate bound to Sinapis alba myrosinase, a plant thioglucosidase, is reported. Myrosinase and its substrates, the glucosinolates, are part of the plant's defence system. The sulfate group and the phenyl group of the inhibitor bind to the aglycon-binding site of the enzyme, whereas the N,N-dimethyl group binds to the glucose-binding site and explains the large improvement in binding affinity compared with previous compounds. The structure suggests ways to increase the potency and specificity of the compound by improving the interactions with the hydrophobic pocket of the aglycon-binding site.
Subject(s)
Enzyme Inhibitors/chemistry , Glycoside Hydrolases/chemistry , Oximes/chemistry , Sinapis/enzymology , Sulfhydryl Compounds/chemistry , Sulfuric Acid Esters/chemistry , Binding Sites , Crystallography, X-Ray , Enzyme Inhibitors/metabolism , Glycoside Hydrolases/antagonists & inhibitors , Glycoside Hydrolases/metabolism , Hydrophobic and Hydrophilic Interactions , Models, Molecular , Oximes/metabolism , Protein Binding , Protein Structure, Tertiary , Sulfuric Acid Esters/metabolismABSTRACT
The synthesis of two enantiomerically pure iminosugars, analogues of 1-L-deoxynojirimycin (l-DNJ) and 1-D-deoxymannojirimycin (DMJ), was achieved using cyclic sulfate substituted isoxazoline derivatives. The piperidine ring was formed via the reduction of an isoxazoline into an amine which underwent a spontaneous intramolecular cyclization by reaction with the cyclic sulfate moiety. The nucleophilic attack of these two trisubstituted piperidines and morpholine on L- and D-erythritol-1,3-cyclic sulfates gave six new nitrogen analogues of salacinol. The inhibitory properties of the synthesized salacinol analogues were evaluated on several commercial glycosidases.