Antioxidant Activity of Styrylpyrones from Inonotus rheades (Agaricomycetes) Mycelium under Oxidative Stress in Thellungiella salsuginea Cell Suspension Culture.

This study examined effects of the styrylpyrone fraction from mycelium of hymenochaetoid species, Inonotus rheades (Agaricomycetes), on reactive oxygen species inhibition in Thellungiella salsuginea cell culture under oxidative stress. We identified antioxidant effects of styrylpyrones from I. rheades mycelium on oxidative stress in T. salsuginea cell suspension culture using two models of oxidative stress (induced by hyperthermia or hydrogen peroxide). The results showed that the styrylpyrone fraction maintained a high level of cell viability under stress conditions. The effect of pure hispidin on the plant cell culture was insignificant during the development of oxidative damage caused by hydrogen peroxide and was lacking during hyperthermia-induced oxidative stress. Therefore, these results suggest that the protective effect of the styrylpyrone fraction on T. salsuginea cells can be exerted by individual compounds (which are part of the fraction) and their complex.

Phenolic Compounds of Inonotus rheades (Agaricomycetes) Mycelium: RP-UPLC-DAD-ESI/MS Profile and Effect of Light Wavelength on Styrylpyrone Content.

The phenolic compounds of Inonotus rheades (Pers.) Bondartsev and Singer (Hymenochaetaceae), a typical xylotrophic basidiomycete, and accumulation of styrylpyrones in mycelium under the influence of light of different wavelengths were investigated. Six styrylpyrones (cis- and trans-hispidin, cis- and trans-bisnoryangonin, and phellinins A1 and A2) and 5 bis(styrylpyrones) (3,14'-bishispidinyl, hypholomin B, 3-bisnoryangonyl-14'-hispidin, 1,1-distyrylpyrylethane, and rheadinin) were detected in the extract of I. rheades mycelium using reversed phase ultra-performance liquid chromatography with diode array detection and electrospray ionization mass spectrometry (RP-UPLC-DAD-ESI/MS). The results showed that the maximal content of styrylpyrones was observed under the influence of blue light (8.10 mg/g of dry mycelium weight). Moreover, hispidin was the dominant compound in all experimental groups. Pigmentation intensity gradually decreased after shifting the light spectrum into darkness. It can be concluded that cultivation of I. rheades mycelium under the blue part of the light spectrum leads to the accumulation of styrylpyrones that have nutraceutical and medicinal significance.