Waterless Dyeing and In Vitro Toxicological Properties of Biocolorants from Cortinarius sanguineus

Abstract

As a part of an ongoing interest in identifying environmentally friendly alternatives to synthetic dyes and in using liquid CO2 as a waterless medium for applying the resulting colorants to textiles, our attention turned to yellow-to-red biocolorants produced by Cortinarius sanguineus fungus. The three principal target anthraquinone colorants (emodin, dermocybin, and dermorubin) were isolated from the fungal bodies using a liquid–liquid separation method and characterized using 700 MHz NMR and high-resolution mass spectral analyses. Following structure confirmations, the three colorants were examined for dyeing synthetic polyester (PET) textile fibers in supercritical CO2. We found that all three biocolorants were suitable for dyeing PET fibers using this technology, and our attention then turned to determining their toxicological properties. As emodin has shown mutagenic potential in previous studies, we concentrated our present toxicity studies on dermocybin and dermorubin. Both colorants were non-mutagenic, presented low cellular toxicity, and did not induce skin sensitization. Taken together, our results indicate that dermocybin and dermorubin possess the technical and toxicological properties needed for consideration as synthetic dye alternatives under conditions that are free of wastewater production.

Anthraquinone biocolourant dermocybin is metabolized whereas dermorubin is not in in vitro liver fractions and recombinant metabolic enzymes

“…Previously, we have studied that they can be utilized in supercritical CO 2 dyeing that does not involve the use of fresh water and that they exhibit low toxicity. 5 In the present work, we studied the previously unknown metabolic properties of dermocybin and dermorubin. We found that dermorubin was not metabolized in in vitro incubation system by human liver microsomal or cytosolic fractions.…”

“…Altogether this data contributes the previous in vitro safety data on dermorubin and dermocybin. 5 European chemical legislation requires in vivo toxicity testing for chemical substances such as biocolourants when entering the market and their production exceeds certain limit. Consequently, it is important to know the metabolism of xenobiotics in different species to increase the reliability of the toxicity assessment.…”

“…The purity and chemical structures of the separated compounds were confirmed by high-performance liquid chromatography coupled with diode-array detection and electrospray ionization tandem mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy. 5…”

“…4 The most commonly present are emodin, dermocybin and dermorubin (Figure 1) in respective dryweight proportions of 63%, 31% and 4%. Recently, it has been shown that they work well in waterless CO 2 dyeing of polyester 5 and in the dyeing of cellulosic fibres. 6 In textiles and food packaging, the dyes could get in touch with skin and gastrointestinal tract, and, therefore, studying their innate toxicity and skin sensitizing properties is warranted.…”

“…Dermorubin and dermocybin are attractive sustainable alternatives for toxic synthetic dyes, due to their low toxicity in in vitro studies. 5 When assessing the safety of dyes or other chemicals, data on their kinetics and especially metabolism are essential, since it is known that metabolism can alter the overall toxicity of chemical substances, including biocolourants. In this study, we set out to identify in vitro metabolites of the previously unstudied C. sanguineus dyes dermocybin and dermorubin in liver microsomal and cytosolic fractions, as well as human recombinant cytochrome P450 (CYP), UGT, sulfotransferase (SULT) and catechol-O-methyl transferase (COMT) enzymes.…”