| Field | Specification |
|---|---|
| Target | |
| CAS no. | |
| Applications | |
| Molecular weight | |
| Molecular formula | C21H24N4O3S |
| Purity | |
| SMILES | |
| Form | Solid |
| Storage | |
| Shipping | |
| Catalog no. (Mfr.) | |
| Main SKU |
Compound Overview
AZ20 is a potent, selective inhibitor of ATR, with an IC50 of 5 nM, and shows 8-fold selectivity over mTOR (IC50 = 38 nM). It is supplied as a white to off-white solid (C21H24N4O3S, MW 412.51) at 99.40% purity.
Physical & Chemical Properties
| CAS Number | 1233339-22-4 |
|---|---|
| Molecular Formula | C21H24N4O3S |
| Molecular Weight | 412.51 g/mol |
| Purity | 99.40% |
| Appearance | Solid |
| Color | White to off-white |
| SMILES | O=S(C1(C2=CC(N3[C@H](C)COCC3)=NC(C4=CC=CC5=C4C=CN5)=N2)CC1)(C)=O |
| Target | ATR, mTOR, PI3Kα |
| Signaling Pathway | Cell Cycle/DNA Damage; PI3K/Akt/mTOR |
| Solubility | In Vitro: DMSO: ≥ 100 mg/mL (242.42 mM; Hygroscopic DMSO has a significant impact on the solubility of product, please use newly opened DMSO) * "≥" means soluble, but saturation unknown. |
| Storage | Powder: -20°C, 3 years; 4°C, 2 years. In solvent: -80°C, 2 years; -20°C, 1 year. |
| Shipping | Room temperature in continental US; may vary elsewhere. |
Biological Activity
IC50 & Target[1]
|
ATR 5 nM (IC50) |
mTOR 38 nM (IC50) |
PI3Kα 13000 nM (IC50) |
Literature Cited
Sources cited in this description and in the In Vitro & In Vivo Data tab. Peer-reviewed publications that used this product are listed under References.
Safety
For Research Use Only. Not for use in diagnostic or therapeutic procedures, and not for human or veterinary use. Handle in accordance with the Safety Data Sheet and your institution's chemical hygiene plan.
In Vitro
| Solvent | Solubility | Notes |
|---|---|---|
| DMSO | ≥ 100 mg/mL (242.42 mM) | use freshly opened DMSO (absorbed moisture lowers solubility) |
Aliquot the stock solution and store it at -80°C (up to 2 years) or -20°C (up to 1 year); avoid repeated freeze-thaw cycles.
In Vivo
Choose the formulation that suits the animal model and route of administration; percentages are volume ratios of the final working solution. Start from a clear DMSO stock (see In Vitro above), add the co-solvents one at a time in the order listed, mixing after each addition, and prepare the working solution fresh on the day of dosing. If precipitation or phase separation occurs, gentle warming or sonication can help.
Protocol 1
| Composition | 10% DMSO + 40% PEG300 + 5% Tween-80 + 45% saline |
|---|---|
| Result | ≥ 2.5 mg/mL (6.06 mM); clear solution |
| How to prepare | Gives a clear solution at ≥ 2.5 mg/mL (saturation not determined). For 1 mL of working solution: add 100 μL DMSO stock (25.0 mg/mL) to 400 μL PEG300; then 50 μL Tween-80; then 450 μL saline to bring the volume to 1 mL. Saline: dissolve 0.9 g sodium chloride in ddH2O and make up to 100 mL. |
Protocol 2
| Composition | 10% DMSO + 90% (20% SBE-β-CD in saline) |
|---|---|
| Result | ≥ 2.5 mg/mL (6.06 mM); clear solution |
| How to prepare | Gives a clear solution at ≥ 2.5 mg/mL (saturation not determined). For 1 mL of working solution: add 100 μL DMSO stock (25.0 mg/mL) to 900 μL 20% SBE-β-CD in saline. 20% SBE-β-CD in saline: dissolve 2 g SBE-β-CD powder in 10 mL saline until clear (4°C, store up to one week). |
Data provided by the manufacturer.
In Vitro
AZ20 inhibits ATR immunoprecipitated from HeLa nuclear extracts, with an IC50 of 5 nM, and inhibits ATR-mediated phosphorylation of Chk1 in HT29 colorectal adenocarcinoma tumor cells, with an IC50 of 50 nM[1].
In Vivo
Despite the lack of progress toward markedly higher solubility, AZ20 (25, 50 mg/kg, p.o.) combines high permeability with good stability in rat hepatocytes and shows respectable bioavailability in a low dose rat PK study. In female nude mice bearing LoVo tumors, AZ20 (25, 50 mg/kg, p.o.) leads to significant tumor growth inhibition[1].
Data provided by the manufacturer. Numbered citations refer to the Literature Cited list in the product description.
Animal Administration[1]
House female Swiss nu/nu mice in negative pressure isolators. Establish LoVo tumor xenografts on the left dorsal flank of 8- to 12-week-old mice by subcutaneous injection of 1×107 tumor cells (100 μL in serum free medium). Randomize animals into treatment groups when tumors become palpable. Prepare AZ20 in 10% DMSO/40% propylene glycol/50% water and administer orally. Measure tumors up to three times per week with calipers. Calculate tumor volumes and plot the data using the geometric mean for each group versus time.
Data provided by the manufacturer. Numbered citations refer to the Literature Cited list in the product description.
Need this compound in a format that drops straight into your assay? We can tailor formulation, chemistry, and documentation so your results stay consistent across runs and re-orders.
- Format options: solid or pre-dissolved solution (choose solvent), target concentration, aliquots, light/moisture-protected packaging
- Chemistry options: free base/acid vs salt forms, hydrate/solvate preference, stereoisomer control (single enantiomer or racemate), close analogs
- Add-on labels & handles: D/¹³C/¹⁵N isotopes (LC-MS/internal standards), azide/alkyne or other functional handles for conjugation
- QC & documentation: standard COA or enhanced analytical pack (HPLC/LC-MS/NMR), chiral purity, residual solvents, water content (KF), method-specific specs
- Scale & continuity: mg to gram scale, bulk pricing, lot reservation, repeat-order continuity
To quote quickly, tell us: compound name + CAS/structure (SMILES or mol file), intended assay context, solvent preference, salt/stereochemistry requirements, purity/QC level, and the amount (mg–g).
Can’t find the compound you’re looking for?
Send the CAS or structure and your specs. We can help source it, suggest close equivalents, or discuss custom synthesis with the right QC documentation (RUO).
E2F activity determines mitosis versus whole-genome duplication in G2-arrested cells. Nat Commun 2025 Jul 21;16(1):6677. PMID: 40691182
Active DNA damage response signaling initiates and maintains meiotic sex chromosome inactivation. Nat Commun 2022 Nov 28;13(1):7212. PMID: 36443288
Myc targeted CDK18 promotes ATR and homologous recombination to mediate PARP inhibitor resistance in glioblastoma. Nat Commun 2019 Jul 2;10(1):2910.
Proteome dynamics at broken replication forks reveal a distinct ATM-directed repair response suppressing DNA double-strand break ubiquitination. Mol Cell 2021 Mar 4;81(5):1084-1099.e6. PMID: 33450211
BET bromodomain inhibitors synergize with ATR inhibitors in melanoma. Cell Death Dis 2017 Aug 10;8(8):e2982.
Torin2 Exploits Replication and Checkpoint Vulnerabilities to Cause Death of PI3K-Activated Triple-Negative Breast Cancer Cells. Cell Syst 2020 Jan 22;10(1):66-81.e11. PMID: 31812693
Combination of PARP inhibitor and temozolomide to suppress chordoma progression. J Mol Med (Berl) 2019 Aug;97(8):1183-1193.
Small molecule inhibitors and a kinase-dead expressing mouse model demonstrate that the kinase activity of Chk1 is essential for mouse embryos and cancer cells. Life Sci Alliance 2020 Jun 22;3(8):e202000671. PMID: 32571801
SLX4IP and telomere dynamics dictate breast cancer metastasis and therapeutic responsiveness. Life Sci Alliance 2020 Feb 18;3(4):e201900427.
Portland State University. 2026.
