Antiviral and antibacterial properties of phloroglucinols: a review on naturally occurring and (semi)synthetic derivatives with potential therapeutic interest

Abstract

Phloroglucinol and derived compounds comprise a huge class of secondary metabolites widely distributed in plants and brown algae. A vast array of biological activities, including antioxidant, anti-inflammatory, antimicrobial, and anticancer has been associated to this class of compounds. In this review, the available data on the antiviral and antibacterial capacity of phloroglucinols have been analyzed. Some of these compounds and derivatives show important antimicrobial properties in vitro. Phloroglucinols have been shown to be effective against viruses, such as human immunodeficiency virus (HIV), herpes or enterovirus, and preliminary data through docking analysis suggest that they can be effective against SARS-CoV-19. Also, some phloroglucinols derivatives have shown antibacterial effects against diverse bacteria strains, including Bacillus subtilis and Staphylococcus aureus, and (semi)synthetic development of novel compounds have led to phloroglucinols with a significantly increased biological activity. However, therapeutic use of these compounds is hindered by the absence of in vivo studies and scarcity of information on their mechanisms of action, and hence further research efforts are required. On the basis of this consideration, our work aims to gather data regarding the efficacy of natural-occurring and synthetic phloroglucinol derivatives as antiviral and antibacterial agents against human pathogens, which have been published during the last three decades. The recollection of results reported in this review represents a valuable source of updated information that will potentially help researchers in the development of novel antimicrobial agents.

Keywords:

• Algae
• antimicrobials
• Hypericum
• phloroglucinol
• SARS-CoV-19
• semisynthesis

Acknowledgments

The authors would like to extend their deepest gratitude to Professor Brian L. Furman, Emeritus Professor of Pharmacology, Strathclyde Institute of Pharmacy and Biomedical Sciences 161, Cathedral Street Glasgow, UK, for his diligent proofreading of this article. MM wants to thank ANID CENTROS BASALES ACE210012. A. Sureda was supported by Instituto de Salud Carlos III, through the Fondo de Investigación para la Salud (Project CIBEROBN CB12/03/30038).

Disclosure statement

The authors report no declarations of interest.

Additional information

Funding

A. Sureda was supported by Instituto de Salud Carlos III, through the Fondo de Investigación para la Salud (Project CIBEROBN CB12/03/30038).