ABSTRACT
Lemonose is a component of the antibiotic lemonomycin and other antibiotics and natural products. Three routes to the synthesis of the title compound, a protected, desmethyl derivative of lemonose, from l-rhamnose or its glycal, were investigated based on electrophilic cyclization, epoxidation-ring opening, and deoxygenation of an intermediate that was used in the synthesis of the amino sugar callipeltose. The deoxygenation route was successful and it provided the title compound, which was then converted to a phenyl thioglycoside.
Subject(s)
Glycosides/chemistry , Glycosides/chemical synthesis , Thioglycosides/chemistry , Carbohydrate SequenceABSTRACT
Auristatins, synthetic analogues of the antineoplastic natural product Dolastatin 10, are ultrapotent cytotoxic microtubule inhibitors that are clinically used as payloads in antibody-drug conjugates (ADCs). The design and synthesis of several new auristatin analogues with N-terminal modifications that include amino acids with α,α-disubstituted carbon atoms are described, including the discovery of our lead auristatin, PF-06380101. This modification of the peptide structure is unprecedented and led to analogues with excellent potencies in tumor cell proliferation assays and differential ADME properties when compared to other synthetic auristatin analogues that are used in the preparation of ADCs. In addition, auristatin cocrystal structures with tubulin are being presented that allow for the detailed examination of their binding modes. A surprising finding is that all analyzed analogues have a cis-configuration at the Val-Dil amide bond in their functionally relevant tubulin bound state, whereas in solution this bond is exclusively in the trans-configuration. This remarkable observation shines light onto the preferred binding mode of auristatins and serves as a valuable tool for structure-based drug design.
Subject(s)
Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Cell Proliferation/drug effects , Depsipeptides/chemistry , Depsipeptides/pharmacology , Drug Discovery , Neoplasms/drug therapy , Animals , Area Under Curve , Cells, Cultured , Crystallography, X-Ray , Drug Screening Assays, Antitumor , Hepatocytes/cytology , Hepatocytes/drug effects , Hepatocytes/metabolism , Humans , Male , Microsomes, Liver/drug effects , Microsomes, Liver/metabolism , Models, Molecular , Molecular Structure , Protein Conformation , Rats , Rats, Wistar , Structure-Activity Relationship , Tandem Mass Spectrometry , Tubulin/metabolismABSTRACT
The synthesis and biological activity of a new series of LpxC inhibitors represented by pyridone methylsulfone hydroxamate 2a is presented. Members of this series have improved solubility and free fraction when compared to compounds in the previously described biphenyl methylsulfone hydroxamate series, and they maintain superior Gram-negative antibacterial activity to comparator agents.
Subject(s)
Amidohydrolases/antagonists & inhibitors , Anti-Bacterial Agents/chemical synthesis , Gram-Negative Bacteria/drug effects , Gram-Negative Bacterial Infections/drug therapy , Hydroxamic Acids/chemical synthesis , Pyridones/chemical synthesis , Sulfonic Acids/chemical synthesis , Animals , Anti-Bacterial Agents/pharmacokinetics , Anti-Bacterial Agents/pharmacology , Crystallography, X-Ray , Humans , Hydroxamic Acids/pharmacokinetics , Hydroxamic Acids/pharmacology , Microbial Sensitivity Tests , Models, Molecular , Molecular Structure , Protein Conformation , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/enzymology , Pyridones/pharmacokinetics , Pyridones/pharmacology , Rats , Stereoisomerism , Structure-Activity Relationship , Sulfonic Acids/pharmacokinetics , Sulfonic Acids/pharmacologyABSTRACT
In this paper, we present the synthesis and SAR as well as selectivity, pharmacokinetic, and infection model data for representative analogues of a novel series of potent antibacterial LpxC inhibitors represented by hydroxamic acid.
