Naphthoquinones and Their Derivatives: Emerging Trends in Combating Microbial Pathogens

Abstract

In the current era, an ever-emerging threat of multidrug-resistant (MDR) pathogens pose serious health challenges to mankind. Researchers are uninterruptedly putting their efforts to design and develop alternative, innovative strategies to tackle the antibiotic resistance displayed by varied pathogens. Among several naturally derived and chemically synthesized compounds, quinones have achieved a distinct position to defeat microbial pathogens. This review unleashes the structural diversity and promising biological activities of naphthoquinones (NQs) and their derivatives documented in the past two decades. Further, realizing their functional potentialities, researchers were encouraged to approach NQs as lead molecules. We have retrieved information that is dedicated on biological applications (antibacterial, antifungal, antiparasitic) of NQs. The multiple roles of NQs offer them a promising armory to combat microbial pathogens including MDR and the ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) group. In bacteria, NQs may exhibit their function in the following ways (1) plasmid curing, (2) inhibiting efflux pumps (EPs), (3) generating reactive oxygen species (ROS), (4) the inhibition of topoisomerase activity. Sparse but meticulous literature suggests the mechanistic roles of NQs. We have highlighted the possible mechanisms of NQs and how the targeted drug synthesis can be achieved via molecular docking analysis. This bioinformatics-oriented approach will explicitly lead to the development of effective and most potent drugs against targeted pathogens. The mechanistic approaches of emerging molecules like NQs might prove a milestone to defeat the battle against microbial pathogens.

Root-associated bacteria modulate the specialised metabolome of Lithospermum officinale L.

“…Despite the interesting properties of naphthoquinones and especially A/Sd ( Mone et al, 2021 ), no studies have been performed so far on the induction of plant naphthoquinones by bacteria. In the present study, the objective was to assess the effects of bacteria on the production of A/Sd in L. officinale .…”

Identification of Potent Bioassay Guided Terpenoid and Glycoside Root Fractions of Astragalus candolleanus against Clinically Significant Bacterial Strains

“…Monoterpenes preferentially affect the membrane structures by enhancing the permeability as well as changing the structural arrangement of proteins, producing interference inside the respiratory chain [ 41 ]. The natural or synthetic quinolone alkaloids have been found to block the action of topoisomerase enzymes, especially type-II variants, thus preventing nuclear replication [ 42 ]. Furthermore, it has been reported that some of the phenols can inhibit the enzymatic activity of the bacterial DNA gyrase by interacting with its ATP site [ 43 ].…”

1,4‐Naphthoquinone Analogs and Their Application as Antibacterial Agents

“…In addition, 1,4‐NQ analogs can covalently modify proteins by promoting the redox cycle to generate ROS and react with tissue‐nucleophilic reagents [57] . Therefore some 1,4‐NQ analogs can act as protease inhibitors to reduce cell wall synthesis and increase cell membrane permeability, thus acting as bacterial inhibitors [58–59] …”