Anti-HIV Screening Libraries

Combination antiretroviral therapy is a key approach to reducing the viral load in HIV-infected people [1-4]. It incorporates several medications with different activity types into an HIV treatment regimen, which curbs the infection and prevents its progression to AIDS. This multidrug strategy has become highly effective and usable over the years, having successfully enhanced the quality of life for HIV-positive individuals.

Around 50 approved HIV medicines [5] may serve as components of a personalized treatment regimen. Depending on a viral target and active substance, they form seven main drug classes [6]. Various medications operate at different stages of the HIV life cycle [7]: some of them prevent the virus from entering the immune system cells; others are able to block enzymes that HIV needs to replicate – reverse transcriptase, protease, and integrase.

This variability of options stems from over 30 years of intense research efforts. However, the resulting ability to control HIV as a chronic disease is just a step towards complete recovery. The cure continues to be one of the greatest medical challenges, which motivates a permanent search for innovative anti-HIV drugs and treatment strategies. Last year a thematic issue of Current Topics in Medicinal Chemistry encompassed a number of notable reviews on HIV/AIDS-related advances and perspectives, with a focus on novel small-molecule drugs for antiretroviral treatment ([8] and references therein). This collection of papers consistently highlights the need for further research in order to reach the final goal: defeat HIV.

In response to this acute need, Life Chemicals contributes to antiretroviral research with a proprietary set of Anti-HIV Screening Libraries:

1. HIV Focused Library (16,800 compounds)
2. HIV Protease Library (760 compounds)
3. HIV Reverse Transcriptase Library (2,100 compounds)

The PAINS filters were not applied to the compound selection since this would have filtered out many relevant analogs of known antiretroviral inhibitors from the reference sets, as those were originally not PAINS-compliant. However, such filtering can be done on the customer’s request.

The compound selection can be customized based on the customer’s requirements. Compound cherry-picking is available. Please contact us at orders@lifechemicals.com for price quotations and any specific requests.

HIV Focused Library

Designed with a 2D fingerprint similarity approach, this Library contains over 16,800 drug-like screening compounds with potential antiretroviral activity.

The reference compound set was extracted from the ChEMBL and BindingDB databases. Thoroughly selected molecules constitute the basis for work on target-specific HIV inhibitors (targeting HIV-related proteins, cell lines, or the whole virus (Fig. 1)). The compounds were chosen using the 75 % similarity cut-off (Tanimoto) on MDL public keys fingerprints.

Among the selected compounds, there are potential inhibitors of the following HIV-specific molecular targets:

• Aberrant vpr protein
• Anti-repression transactivator
• Envelope glycoprotein gp160
• Envelope polyprotein GP160
• HIV1 integrase
• HIV1 protease
• HIV1 reverse transcriptase
• HIV1 Tat protein
• HIV1 enhancer-binding protein 1

Fig. 1. Compound distribution targeting organism- and single protein targets within the HIV Focused Library.

HIV Protease Library

HIV protease is an enzyme that takes part in the infection process by splitting proteins into smaller units and using them to create the mature protein components of an infectious HIV virion [11]. Inhibition of HIV protease disrupts the ability of the retrovirus to replicate and to infect other cells.

760 small-molecule compounds of potential HIV protease inhibitors were selected with a 2D similarity search (Tanimoto 75 % similarity cut-off on MDL public keys fingerprints) (Fig. 2A).

HIV Reverse Transcriptase Library

One approach to hinder the virus replication is inhibition of HIV reverse transcriptase, one of the enzymes that the retrovirus uses for self-copying. This enzyme catalyzes the conversion of single-stranded viral RNA into proviral DNA, which further infects the host cell DNA [9, 10]. Corresponding targeted drugs (nucleoside and non-nucleoside reverse transcriptase inhibitors) exclude reverse transcriptase from the infectious process by either blocking it or altering its structure.

The Life Chemicals HIV Reverse Transcriptase Library comprises 2,100 compounds identified with a 2D similarity search (Tanimoto 75 % similarity cut-off on MDL public keys fingerprints), which can potentially act as HIV reverse transcriptase inhibitors (Fig. 2B).

Fig. 2. Compound distribution by the presence of the main chemical groups in their chemical structure within the HIV Protease Library (A) and HIV Reverse Transcriptase Library (B).

References

1. Lu, D. Y.; Wu, H. Y.; Yarla, N. S. et al. (2018). HAART in HIV/AIDS Treatments: Future Trends. Infect Disord Drug Targets 18(1):15‐22. DOI: 10.2174/1871526517666170505122800
2. Maenza, J., Charles Flexner, C. (1998). Combination Antiretroviral Therapy for HIV Infection. Am Fam Physician 57(11):2789-2798.https://www.aafp.org/afp/1998/0601/p2789.html
3. Pomerantz, R.J.; Horn, D.L. (2003). Twenty years of therapy for HIV-1 infection. Nat Med. 9, 867-873. DOI: 10.1038/nm0703-867
4. Arts, E. J., & Hazuda, D. J. (2012). HIV-1 antiretroviral drug therapy. Cold Spring Harbor perspectives in medicine, 2(4), a007161. DOI: 10.1101/cshperspect.a007161
5. https://aidsinfo.nih.gov/understanding-hiv-aids/fact-sheets/21/58/fda-approved-HIV-medicines
6. Maeda, K., Das, D., Kobayakawa, T., Tamamura, H., & Takeuchi, H. (2019). Discovery and Development of Anti-HIV Therapeutic Agents: Progress Towards Improved HIV Medication. Curr. Top. Med. Chem., 19(18), 1621–1649. DOI: 10.2174/1568026619666190712204603
7. Saha, M., & Bhattacharya, S. (2019). Recent Developments in the Medicinal Chemistry for New Small-Molecule Therapeutics to Treat HIV-AIDS. Curr. Top. Med. Chem., 19(18), 1569–1570. DOI: 10.2174/156802661918191009110427
8. Mitsuya, H., Yarchoan, R., Kageyama, S. and Broder, S. (1991), Targeted therapy of human immunodeficiency virus‐related disease. The FASEB Journal, 5: 2369-2381. DOI: 10.1096/fasebj.5.10.1712326
9. Xavier Ruiz, F., & Arnold, E. (2020). Evolving understanding of HIV-1 reverse transcriptase structure, function, inhibition, and resistance. Current Opinion in Structural Biology, 61, 113–123. DOI: 10.1016/j.sbi.2019.11.011
10. Wang, Y., De Clercq, E., & Li, G. (2019). Current and emerging non-nucleoside reverse transcriptase inhibitors (NNRTIs) for HIV-1 treatment. Expert Opinion on Drug Metabolism & Toxicology. 15:10, 813-829, DOI: 10.1080/17425255.2019.1673367
11. Voshavar, C. Protease inhibitors for the treatment of HIV/AIDS: Recent advances and future challenges. (2019). Curr. Top. Med. Chem., 19(18), 1571-1598. DOI: 10.2174/1568026619666190619115243