Chemical Constituents of the Mushroom Dictyophora indusiata and Their Anti-Inflammatory Activities

As an edible and medicinal fungus, Dictyophora indusiata is well-known for its morphological elegance, distinctive taste, high nutritional value, and therapeutic properties. In this study, eighteen compounds (1-18) were isolated and identified from the ethanolic extract of D. indusiata; four (1-4) were previously undescribed. Their molecular structures and absolute configurations were determined via a comprehensive analysis of spectroscopic data (1D/2D NMR, HRESIMS, ECD, and XRD). Seven isolated compounds were examined for their anti-inflammatory activities using an in vitro model of lipopolysaccharide (LPS)-simulated BV-2 microglial cells. Compound 3 displayed the strongest inhibitory effect on tumor necrosis factor-alpha (TNF-alpha) expression, with an IC50 value of 11.9 mu M. Compound 16 exhibited the highest inhibitory activity on interleukin-6 (IL-6) production, with an IC50 value of 13.53 mu M. Compound 17 showed the most potent anti-inflammatory capacity by inhibiting the LPS-induced generation of nitric oxide (NO) (IC50: 10.86 mu M) and interleukin-1 beta (IL-1 beta) (IC50: 23.9 mu M) and by significantly suppressing induced nitric oxide synthase (iNOS) and phosphorylated nuclear factor-kappa B inhibitor-alpha (p-I kappa B-alpha) expression at concentrations of 5 mu M and 20 mu M, respectively (p < 0.01). The modes of interactions between the isolated compounds and the target inflammation-related proteins were investigated in a preliminary molecular docking study. These results provided insight into the chemodiversity and potential anti-inflammatory activities of metabolites with small molecular weights in the mushroom D. indusiata.

Automated summary

In this study, eighteen compounds were isolated and identified from the ethanolic extract of Dictyophora indusiata. Four of these compounds were previously undescribed. The molecular structures and absolute configurations of these compounds were determined, and their anti-inflammatory activities were examined.