A22

A22
Name	A22
Othernames	S-(3,4-dichlorobenzyl)isothiourea?

A22 is a small-molecule inhibitor widely used in experimental studies of bacterial cell shape and cytoskeletal dynamics. It is frequently cited in literature investigating rod-shaped bacteria, cytoskeletal proteins, and antibiotic action, and has been applied in studies involving organisms such as Escherichia coli, Bacillus subtilis, Caulobacter crescentus, and Mycobacterium tuberculosis. Researchers working at institutions including the National Institutes of Health, Max Planck Institute for Biology, and universities such as Harvard University, University of Cambridge, and Stanford University have used A22 to probe roles of the actin homolog MreB and related morphogenetic systems.

Definition and Nomenclature

A22 is commonly identified by its research code and commercial trade names used by suppliers and chemical vendors in catalogues. The compound appears in compound libraries screened at facilities like Broad Institute and Wellcome Trust Sanger Institute, and is referenced in chemical databases curated by organizations such as the Chemical Abstracts Service and PubChem. In structure–activity relationship reports and medicinal chemistry papers from groups at Pfizer, GlaxoSmithKline, and academic medicinal chemistry laboratories, A22 is often cross-referenced with analogues studied in structure elucidation and binding assays. Nomenclature in patent filings by companies including Eli Lilly and Company occasionally uses systematic identifiers alongside the common research name.

Chemical Structure and Mechanism of Action

The molecular scaffold of A22 has been characterized in biochemical and crystallographic studies conducted by teams at European Molecular Biology Laboratory and structural biology groups at University of Oxford. Structural analyses using techniques pioneered at facilities like Diamond Light Source and Advanced Photon Source have informed models of A22 binding to the bacterial actin homolog MreB, originally visualized in cryo-electron microscopy studies at centers such as EMBL-EBI. Mechanistically, A22 perturbs the polymerization dynamics of MreB by interacting with nucleotide-binding or monomer–monomer interfaces, a mode comparable to small-molecule interactions described for other cytoskeletal inhibitors studied at Johns Hopkins University and Massachusetts Institute of Technology. These interactions alter filament curvature and stability, analogous to inhibitor effects on actin described in work from Max Planck Institute for Biophysical Chemistry.

Biological Activity and Research Applications

A22 has been employed as a tool compound in cell biology and microbiology studies across model organisms used by laboratories at California Institute of Technology, University of Tokyo, and ETH Zurich. It induces morphological transitions from rod-shaped to spherical cells in organisms such as E. coli and C. crescentus, enabling experiments on cell wall synthesis pathways involving enzymes characterized at Rockefeller University and ETH Zurich. A22 has been used alongside fluorescent fusion proteins developed at European Molecular Biology Laboratory and imaging platforms from Nikon and Zeiss to study MreB dynamics, peptidoglycan insertion, and coordination with division proteins studied in work at University of California, San Francisco and Princeton University. In high-throughput screens at institutes like Broad Institute, A22 and derivatives have been profiled for synergy with antibiotics investigated at Centers for Disease Control and Prevention and World Health Organization antimicrobial resistance programs.

Pharmacology and Toxicology

Pharmacological characterization of A22 has appeared in preclinical studies performed by academic pharmacology groups at Imperial College London and University of Pennsylvania. In vitro exposure alters bacterial viability in concentration-dependent assays comparable to methods standardized by Clinical and Laboratory Standards Institute and data repositories such as ArrayExpress. Toxicology profiling in model systems including Saccharomyces cerevisiae and mammalian cell lines used by laboratories at National Cancer Institute has informed safety margins and off-target effects; these studies assess cytotoxicity, membrane perturbation, and mitochondrial effects similar to investigations published by groups at University of California, San Diego. Pharmacokinetic reports remain limited, and A22 is primarily used as a laboratory reagent rather than a clinical candidate, as discussed in reviews from Nature Reviews Microbiology and position papers by committees at European Medicines Agency.

Synthesis and Chemical Properties

Synthetic methods for A22 and analogues have been reported in organic chemistry journals where groups at MIT, ETH Zurich, and University of California, Berkeley described routes involving thiourea formation, aromatic substitution, and purification techniques compatible with protocols from American Chemical Society publications. Physical properties such as solubility, stability, and spectral data have been catalogued by compound suppliers and in university core facilities at Stanford University and Yale University. Chemical modifications to enhance potency, selectivity, or cell permeability have been pursued in medicinal chemistry campaigns at GlaxoSmithKline and academic laboratories collaborating with structural groups at European Synchrotron Radiation Facility.

Historical Development and Notable Studies

A22 emerged in the literature when cell-shape and cytoskeletal research advanced through landmark studies at institutions like Rockefeller University and Max Planck Institute for Developmental Biology. Seminal papers demonstrating MreB inhibition and resulting morphological changes were published by research teams affiliated with Harvard Medical School and University of Oxford, and follow-up work from groups at Johns Hopkins University and University of Wisconsin–Madison expanded understanding of MreB function. Notable studies include high-resolution imaging of MreB dynamics, genetic suppressor analyses from laboratories at Columbia University and University of Chicago, and chemical-genetic interaction maps produced in consortium projects involving Broad Institute and Sanger Institute. Continued research on A22 and derivatives informs basic science on bacterial cytoskeletons and contributes to antimicrobial strategy discussions at forums hosted by World Health Organization and academic conferences such as meetings of the American Society for Microbiology.

Category:Chemical compounds