## 3 Results
### Toxicity Prediction
Class 2 includes six compounds with a predicted LD\({}_{50}\) below 50 mg/kg, which are considered highly toxic and can be fatal if ingested. Notably, in this screening, we did not identify any compound with LD\({}_{50}\)\(\leq\) 5 mg/kg, which is considered to indicate lethality at such low doses. The organ-specific toxicity analysis revealed that most compounds exhibited a low probability of causing liver damage, and all compounds were classified as inactive for hepatotoxicity (Table S4, Supplementary Materials). However, some compounds showed activity in other organs, such as ergosterol and (22\(E\))-ergosta-5,7,22-trien-3\(\beta\)-ol, both associated with neurotoxicity. For nephrotoxicity, officimalonic acid C was identified as toxic. For respiratory toxicity, most of the compounds were predicted to be toxic, suggesting a significant impact on the respiratory system. At the same time, cardiotoxicity was less prevalent, with polyporosterone A presenting a low risk. The control ratiquidar, with predicted active toxicity in terms of both nephrotoxicity and respiratory toxicity, and ergosterol, with active predicted toxicity in multiple systems, deserve to be highlighted due to their combined toxicity profile. The analysis of the predicted toxicity endpoints indicated that several bioactive compounds may present carcinogenic potential (Table S4, Supplementary Materials). Although most compounds showed low predicted immunotoxicity, some indicated immunotoxicity, such as polyporgenic acid C. These results suggest that certain compounds may impact the immune system. The analyses revealed that most of the compounds evaluated did not show significant mutagenicity, which is beneficial for their development as therapeutic agents. Most compounds showed low predicted cytotoxicity, except for pipotlinic acid E, which showed more significant cytotoxic activity. These results indicate that, although some compounds may present toxicity at specific endpoints, many have acceptable toxicological profiles, reinforcing their potential. An analysis of the predicted activity of the mushroom-derived database of compounds against nuclear receptors revealed significant potential in various signaling pathways related to hormonal, metabolic, and inflammatory processes. Compounds such as ganoderic acid (T, W, and X), officimalinic acid, and other lanostanoid derivatives demonstrated active toxicity towards androgen receptors (ARs) and the androgen receptor ligand-binding Domain (AR-LBD). In contrast, compounds such as (22\(E\))-19-noregosta-5,7,9,22-tetraen-3\(\beta\)-ol, inonotsuoxodi A, equuricoic acid, ganoderic acid Y, and others were predicted to be inactive regarding the receptors evaluated. Analyzing the predicted activity in cellular stress response pathways revealed that, although most of the compounds tested did not show activity, some did show toxicity in specific pathways, such as Nrf/ARE, HSE, and MMP. As an example, inontousol B and polyporenic acid C showed predicted toxicity in multiple pathways. Notably, none of the compounds tested were predicted to be toxic to p53, which is essential when considering anticancer therapies. Analyses of molecular initiating events revealed that several bioactive compounds, such as ganoderic acid T and ganoderic acid W, showed predicted activity against GABA receptors and pregnane X receptor (PXR). Meanwhile, other compounds, such as 5\(\alpha\),8\(\alpha\)-epidioxy-24(R)-methylcholesta-6,22-dien-3\(\beta\)-D-glucopyranoside, polyporusterone A, lucidumol A, and antcin K, proved to be inactive regarding various receptors. Most of the compounds evaluated were predicted to be inactive against CYP1A2, CYP2C19, CYP2C9, CYP2D6, CYP3A4, and CYP2E1, enzymes belonging to the cytochrome P450 (CYP) family, which are essential for the metabolism of medications and other chemical substances in the body [37]. However, some compounds showed specific toxicity in certain isoforms. For example, ergosta-4,6,8(14),22-tetraen-3-one was predicted to be toxic to CYP2C9.