Novel Xylenyl-Spaced Bis-Thiazoles/Thiazines: Synthesis, Biological Profile as Herpes Simplex Virus Type 1 Inhibitors and inSilico Simulations

Abstract

Aims: Development of some potent bis-thiazole and bis-thiazine derivatives that could be used as antiviral prototypes. Materials & methods: Xylenyl-spaced bis-carbazone scaffold 3 was used as a versatile building block for bis-thiazole derivatives 6a–e and 9a–d and bis-thiazine derivatives 12a–f. These bis-heterocycles were screened as herpes simplex virus type 1 (HSV-1) inhibitors. Results: The new bis-heterocyclic compounds showed remarkable antiviral activity (e.g., compound 6d cytotoxicity concentration CC₅₀ >500 μg/ml). The antiviral capacity of the synthesized bis-compounds was supported by a molecular docking study against the glycoprotein D receptor of HSV-1. Compounds 6b, 9b, and 12c displayed the best binding coefficients. Conclusion: A new series of xylenyl-spaced bis-carbazone scaffolds were used as a building scaffold to construct a host of bis-thiazole/thiazine derivatives that could be used as antiviral prototypes.

Plain language summary

Three series of potent antiviral prototypes were successfully designed. The building blocks of these prototypes are readily accessible from commercially available starting materials. These prototypes were tagged with thiazole moieties due to their diverse biological activities. These analogues were screened as herpes simplex virus type 1 (HSV-1) inhibitors to examine their antiviral potential. In vitro screening revealed that several prototypes possess good antiviral activities against an HSV-1 receptor compared with acyclovir. Compound 6d showed remarkable antiviral activity with a cytotoxicity concentration CC₅₀ >500 μg/ml. The antiviral capability of the newly synthesized materials was supported by computational calculations against the surface glycoprotein D receptor of the HSV-1. Compounds 6b, 9b and 12c had the best binding affinity toward the target protein receptor, with binding energies of -9.5, -9.8 and -9.6 kcal/mol, respectively. These results were in great accord with the recorded in vitro screening data.

Tweetable abstract

A group of potent antiviral prototypes were successfully synthesized. In vitro screening of these prototypes revealed that several examples possess good antiviral activities against a herpes simplex virus type 1 receptor protein compared with acyclovir.

Keywords::

• bis-thiazoles
• HSV-1 inhibitors
• in silico simulations
• xylenyl-spaced bis-carbazones

Acknowledgements

The authors are deeply indebted to the Deanship of Scientific Research, Imam Mohammad Ibn Saud Islamic University, Saudi Arabia, for the continuous support.

Financial disclosure

The authors have no financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Competing interests disclosure

The authors have no competing interests or relevant affiliations with any organization or entity with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending or royalties.

Writing disclosure

No writing assistance was utilized in the production of this manuscript.