Inhibitors of bacterial and mammalian hyaluronidases: design, synthesis and structure-activity relationships with focus on human enzymes

摘要: There is a need for hyaluronidase inhibitors as pharmacological tools to study the (patho)physiological role of these enzymes. As such compounds could also be useful drugs, e.g. in treatment (bacterial) infections, arthroses and cancer or contraceptives, goal this thesis was synthesis, identification structural optimization low molecular weight inhibitors. The synthesized were tested turbidimetric assay inhibition recombinantly expressed human hyaluronidases Hyal-1 PH-20, bovine testicular (BTH) bacterial hyaluronate lyase (SagHyal4755). In first approach derivatives glucurono-6,3-lactone synthesized. 1-O-Alkyl inactive only weakly active on BTH but exhibited pronounced PH-20 SagHyal4755. The inhibitory potency against all investigated increased by adding polar substituents (IC50 values lower micromolar range). Furthermore, 1-O-alkyl-gluco-furanosiduronic acids -uronamides prepared which proved preferably SagHyal4755. In second various ascorbic acid with hydrophobicity since its 6-O-palmitoyl derivative proven X-ray crystallography bind center hyaluronidase. A clear correlation between chain length 6-alkanoyl residue found. Whereas BTH, SagHyal4755 most potently inhibited 6-O-palmitate, strongest achieved 6-O-tridecanoate. differences activity became even more prominent when bearing biaryl residues investigated: rather small modifications terminal phenyl led different structure-activity relationships (SAR) hyaluronidases. Among 6-O-[11-(4-phenylphenoxy)undecanoyl]ascorbic identified one potent known so far an IC50 value 1.3 µM. �Bivalent� inhibitors, characterized two vitamin C moieties connected alkanedioyl spacer groups, roughly equipotent corresponding �monovalent� ligands. By contrast, 5,6-di-O-acylation significantly enhanced compared monoacylation. due diacylation evident where up 26-fold higher obtained. Introduction carboxylic hyaluronidases, 2-O-(5-carboxypentanoyl)-6-O-hexadecanoyl-L-ascorbic [µM]: 8.3 (Hyal-1), 2.0 (PH-20), 27 (BTH), 2.8 (SagHyal4755)) represents inhibitor developed work thus date. Additionally 2-, 3- 6-O-alkylated respect stability under physiological conditions esters. Strikingly, distinct SAR mammalian are obvious series again. The recently published crystal structure used 3-D model perform automated (FlexiDock) well manual docking using based suggested binding modes appropriate explain several characteristics provide basis further structure-based development inhibitors. In third synthetic indole Especially �bivalent� indole-3-butanoic acids, containing large hydrophobic fragments manifold substituted indoles (e.g. 2-carboxy-5-(hexadecan-1-yl)oxy-1H-indole-3-butanoic acid, 3.4 (SagHyal4755)). These selectivity other Previously, has been broadly accepted enzyme This working hypothesis challenged results strongly some homolog not. Whereas additional approaches develop carbohydrate- peptide-based failed, among melophlins alkylphosphocholines. With planned vivo investigations selected detail. cytotoxicity not detected micelle formation hemolytic at irrelevantly high concentrations, plasma protein must considered investigations.