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PD 0332991 isethionate

≥98% (HPLC)

Palbociclib isethionate, 6-acetyl-8-cyclopentyl-5-methyl-2-[[5-(1-piperazinyl)-2-pyridinyl]amino]pyrido[2,3-d]pyrimidin-7(8H)-one 2-hydroxy-ethanesulfonic acid (1:1)
Empirical Formula (Hill Notation):
C24H29N7O2 · C2H6O4S
CAS Number:
Molecular Weight:
MDL number:
PubChem Substance ID:

Quality Level


≥98% (HPLC)






white to beige


H2O: 5 mg/mL, clear



storage temp.

room temp

SMILES string




InChI key


Gene Information

Related Categories


PD 0332991 isethionate has been used:
  • to incubate MCF10A cells to verify cyclin D1 inhibition of autophagy involved cyclin-dependent kinase activity
  • as a cyclin dependent kinase 4 (CDK4) inhibitor to study its anticonvulsive property in Drosophila
  • to mimic the inhibitory effect of 5α-dihydrotestosterone (DHT) on HPr-1AR cell cycle progression and growth


5, 25 mg in glass bottle

Biochem/physiol Actions

PD 0332991 is a potent selective inhibitor of cyclin dependent kinases CDK4 and CDK6 with in vitro IC50 = 11 nM (CDK4) and 16 nM (CDK6). PD 0332991 induces G1 arrest in retinoblastoma (Rb)-positive tumor cells.
PD 0332991 might act as a chemsensitizer. It is useful in the treatment of breast cancer along with antioestrogens. PD 0332991 is also known to possess antitumor action.

Features and Benefits

This compound is featured on the CDKs page of the Handbook of Receptor Classification and Signal Transduction. To browse other handbook pages, click here.

Other Notes

This compound was developed by Pfizer for Kinase Phosphatase Biology research. To learn more about Sigma′s partnership with Pfizer and view other authentic, high-quality Pfizer compounds, visit

To browse the list of other pharma-developed compounds and Approved Drugs/Drug Candidates, click here.
PD0332991 has been expertly reviewed and recommended by the Chemical Probes Portal. For more information, please visit the PD0332991 probe summary on the Chemical Probes Portal website.

Legal Information

Sold for research purposes under agreement from Pfizer Inc.
Pfizer is a registered trademark of Pfizer, Inc.


Skull and crossbones

Signal Word


Hazard Statements

Precautionary Statements

Hazard Classifications

Acute Tox. 3 Oral

Storage Class Code

6.1D - Non-combustible, acute toxic Cat.3 / toxic hazardous materials or hazardous materials causing chronic effects



Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Certificate of Analysis

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Certificate of Origin

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More Documents

Quotes and Ordering

Cyclin D1 Restrains Oncogene-Induced Autophagy by Regulating the AMPK-LKB1 Signaling Axis
Casimiro MC, et al.
Cancer Research, 77(13), 3391-3405 (2017)
Craig P Giacomini et al.
PLoS genetics, 9(4), e1003464-e1003464 (2013-05-03)
Gene fusions, like BCR/ABL1 in chronic myelogenous leukemia, have long been recognized in hematologic and mesenchymal malignancies. The recent finding of gene fusions in prostate and lung cancers has motivated the search for pathogenic gene fusions in other malignancies. Here
Checkpoint Controls and Targets in Cancer Therapy, 141-141 (2010)
Androgen-Sensitized Apoptosis of HPr-1AR Human Prostate Epithelial Cells
Chen C, et al.
PLoS ONE, 11(5), e0156145-e0156145 (2016)
C Yang et al.
Oncogene, 36(16), 2255-2264 (2016-10-18)
Dysregulated activation of the CDK4/6 kinases is a hallmark of most mammary-derived carcinomas. ATP-competitive inhibitors against this complex have been recently advanced in the clinic and have shown significant activity, particularly against tumors driven by the estrogen receptor (ER). However


Cyclin-dependent Kinases (CDKs)

Cyclin dependent kinases (CDKs) are typical serine/threonine kinases that display the 11 subdomains shared by all kinases. The complete sequence of the Homo sapiens genome shows that among the ~30,000 predicted genes, there are 13 CDKs and 25 cyclins. Eleven CDKS and their associated cyclins have been characterized in man.

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