Exploring Anthraquinones as Antibacterial and Antifungal agents

Abstract

Anthraquinones having an anthracene core structure with two carbonyl groups are essential compounds in therapeutic applications. One of the growing concerns within the medical community is antimicrobial resistance. Multiple drug-resistant microbes can worsen a disease that can be easily treated with normal drugs. Microbes also produce biofilms that further enhance their resistance to antimicrobials, rendering biofilm-associated infections challenging to eradicate. This review provides an update on the antibacterial and antifungal activities of natural and synthetic anthraquinone derivatives. The mechanism of antibacterial and antifungal action of anthraquinones are summarised, which will help in designing new therapeutically effective anthraquinone compounds.

Alizarin old and new: Extraction techniques for coloration, advances in detection methods for historical textiles and novel applications as a functional dye

“…154,155 Especially, the anthraquinone backbone of alizarin, which contains two hydroxyl units at the carbon-1 (C-1) and carbon-2 (C-2) positions, disrupts the bacterial cells by inhibiting the establishment of bacterial biofilms. 156,157 The effect of varying the concentration of alizarin on its antibacterial activities against E. coli and St. aureus is presented in Figure 6A,B.…”

“…The anti-fungal property of alizarin is attributed to the presence of the -OH group at the C-1 position, which is responsible for reducing biofilm formation, indicating the potential of alizarin as a natural anti-fungal agent. 157,159…”

“…The remarkable antibacterial effect of the dye extracts was attributed to the ability of alizarin to form complexes with amino acids in bacterial proteins, causing protein function deactivation and bacterial growth inhibition 154,155 . Especially, the anthraquinone backbone of alizarin, which contains two hydroxyl units at the carbon‐1 (C‐1) and carbon‐2 (C‐2) positions, disrupts the bacterial cells by inhibiting the establishment of bacterial biofilms 156,157 . The effect of varying the concentration of alizarin on its antibacterial activities against E. coli and St. aureus is presented in Figure 6A,B.…”

“…Furthermore, at a low concentration (2 μg mL −1 ), alizarin inhibited the hyphal growth of Candida albicans (Figure 6C) and destroyed its mature biofilms. The anti‐fungal property of alizarin is attributed to the presence of the –OH group at the C‐1 position, which is responsible for reducing biofilm formation, indicating the potential of alizarin as a natural anti‐fungal agent 157,159 …”

Rhein against Staphylococcus xylosus by interfering with respiratory metabolism and inducing oxidative stress

“…Rhein exhibits a broad spectrum of pharmacological activities, including anti-inflammatory, anti-tumor, hypoglycemic, and bacteriostatic effects ( Gao et al, 2014 ; Liu et al, 2021 ). It has demonstrated effective antibacterial properties against Porphyromonas gingivalis , Staphylococcus aureus , Methicillin-resistant Staphylococcus aureus (MRSA) and so on ( Liao et al, 2013 ; Yu et al, 2008 ; Raghuveer et al, 2023 ; Peerzada et al, 2022 ). However, little is known about the antibacterial effect of rhein against S. xylosus .…”