Fungal Anthraquinone Photoantimicrobials Challenge the Dogma of Cationic Photosensitizers

23 December 2022, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


The photoantimicrobial potential of four mushroom species (i.e., Cortinarius cinnabarinus, C. sanguineus, C. rubrophyllus, and C. holoxanthus) was explored based on a light modified EUCAST protocol. The extracts were tested against Candida albicans, Escherichia coli, and Staphylococcus aureus under blue (λ = 428 nm and λ = 478 nm, H = 30 J cm-2) and green light (λ = 528 nm, H = 30 J cm-2) irradiation. Three extracts showed significant photoantimicrobial effects at concentrations below 25 µg/mL. Targeted isolation of the major pigments from C. sanguineus led to the identification of two new potent photoantimicrobials, one of them (i.e., dermocybin) being active against S. aureus and C. albicans under green light irradiation (PhotoMIC523 = 39.5 µM and 2.3 µM, respectively) and the other one (i.e., emodin) being active against E. coli in a low micromolar range (PhotoMIC428 = 11.1 µM). Intriguingly, dermocybin was not (photo)cytotoxic against three tested cell lines adding an additional level of selectivity. Since both photoantimicrobials are not charged, this discovery shifts the paradigm of cationic photosensitizers.


Fungal photosensitizers
dermoyboid Cortinarii
Cortinarius sanguineus
Escherichia coli
Candida albicans
Staphylococcus aureus

Supplementary materials

Supplementary Part Fungal Anthraquinones are potent Photoantimicrobials bucking the dogma of cationic photosensitizers
Information regarding the biomaterial used; NMRs; Micrographs of cell cultures


Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.