Identification of flavopiridol analogues that selectively inhibit positive transcription elongation factor (P-TEFb) and block HIV-1 replication

UMMS Affiliation

Department of Biochemistry and Molecular Pharmacology; Program in Molecular Medicine

Publication Date


Document Type



Anti-HIV Agents; Cell Proliferation; Drug Evaluation, Preclinical; Flavonoids; HIV-1; Hela Cells; Humans; Microbial Sensitivity Tests; Molecular Structure; Piperidines; Positive Transcriptional Elongation Factor B; inhibitors; Virus Replication


Life Sciences | Medicine and Health Sciences


The positive transcription elongation factor (P-TEFb; CDK9/cyclin T1) regulates RNA polymerase II-dependent transcription of cellular and integrated viral genes. It is an essential cofactor for HIV-1 Tat transactivation, and selective inhibition of P-TEFb blocks HIV-1 replication without affecting cellular transcription; this indicates that P-TEFb could be a potential target for developing anti-HIV-1 therapeutics. Flavopiridol, a small molecule CDK inhibitor, blocks HIV-1 Tat transactivation and viral replication by inhibiting P-TEFb kinase activity, but it is highly cytotoxic. In the search for selective and less cytotoxic P-TEFb inhibitors, we prepared a series of flavopiridol analogues and evaluated their kinase inhibitory activity against P-TEFb and CDK2/cyclin A, and tested their cellular antiviral potency and cytotoxicity. We identified several analogues that selectively inhibit P-TEFb kinase activity in vitro and show antiviral potency comparable to that of flavopiridol, but with significantly reduced cytotoxicity. These compounds are valuable molecular probes for understanding P-TEFb-regulated cellular and HIV-1 gene transcription and provide potential anti-HIV-1 therapeutics.

DOI of Published Version



Chembiochem. 2009 Aug 17;10(12):2072-80. Link to article on publisher's site

Journal/Book/Conference Title

Chembiochem : a European journal of chemical biology

Related Resources

Link to Article in PubMed

PubMed ID