UPLC-ESI-MS/MS-based widely targeted metabolomics reveals differences in metabolite composition among four Ganoderma species

The Chinese name "Lingzhi" refers to Ganoderma genus, which are increasingly used in the food and medical industries. Ganoderma species are often used interchangeably since the differences in their composition are not known. To find compositional metabolite differences among Ganoderma species, we conducted a widely targeted metabolomics analysis of four commonly used edible and medicinal Ganoderma species based on ultra performance liquid chromatography-electrospray ionization-tandem mass spectrometry. Through pairwise comparisons, we identified 575-764 significant differential metabolites among the species, most of which exhibited large fold differences. We screened and analyzed the composition and functionality of the advantageous metabolites in each species. Ganoderma lingzhi advantageous metabolites were mostly related to amino acids and derivatives, as well as terpenes, G. sinense to terpenes, and G. leucocontextum and G. tsugae to nucleotides and derivatives, alkaloids, and lipids. Network pharmacological analysis showed that SRC, GAPDH, TNF, and AKT1 were the key targets of high-degree advantage metabolites among the four Ganoderma species. Analysis of Gene Ontology and Kyoto Encyclopedia of Genes and Genomes demonstrated that the advantage metabolites in the four Ganoderma species may regulate and participate in signaling pathways associated with diverse cancers, Alzheimer's disease, and diabetes. Our findings contribute to more targeted development of Ganoderma products in the food and medical industries.

Evaluation of the acute toxicity and 28-days subacute toxicity of the alcoholic extract from Ganoderma leucocontextum

Ganoderma leucocontextum is a well-known traditional medicine in Tibet Autonomous Region, which has benefits, such as anti-hypoxia, neurotrophic action on nerves, easing coughs and relieving asthma, strengthening the body and prolonging life. However, few research have focused on its negative effects, possibly jeopardizing its safety. The purpose of this study is to evaluate the acute and subacute toxicity of an alcoholic extract from G. leucocontextum (GLA) in vivo. The phytochemical characterization analysis showed that alcoholic extract from G. leucocontextum were rich in polysaccharides, triterpenoids. Then, in acute oral toxicity, male and female mice from Institute of Cancer Research (ICR) were orally administered with 16 g/kg GLA and were observed for 14 days. In the subacute toxicity, male and female Sprague-Dawley (SD) rats were orally administered with 2, 4, and 8 g/kg doses of GLA for 28 days. There was no death or clinical changes in male and female mice in the acute toxicity test. During the subacute toxicity test, the difference in body weights, food consumption, biochemical and hematological parameters, and organ coefficients between treated and control groups were unrelated to GLA treatment. The obtained data show that the GLA had no significant toxic effects when administered orally to male and female rats in acute and subacute toxicity.

Immunoregulatory activity of a low-molecular-weight heteropolysaccharide from Ganoderma leucocontextum fruiting bodies in vitro and in vivo

The chemical structure of GLP-1, a novel water-soluble heteropolysaccharide purified Ganoderma leucocontextum fruiting bodies, has been characterized in our previous study. This study aimed to investigate the immunostimulatory activity of GLP-1 in vitro and in vivo by using RAW264.7 macrophages and cyclophosphamide-induced immunosuppressed mice model. Results showed that GLP-1 was able to enhance phagocytic activity and promote the production of reactive oxygen species, nitric oxide, tumor necrosis factor-α, interleukin-6, and monocyte chemoattractant protein-1 in RAW264.7 macrophages. Moreover, GLP-1 could activate mitogen-activated protein kinase, phosphatidylinositol-3-kinase/protein kinase B, and nuclear factor-kappa B signaling pathways through toll-like receptor 2 and dectin-1 receptors. Furthermore, GLP-1 increased the thymus index, serum immunoglobulin levels, and percentage of CD3⁺ T lymphocytes in cyclophosphamide-induced immunosuppressed mice. These results demonstrated that GLP-1 possessed significant immunostimulatory effects in vivo and in vitro and could be developed as an effective immunomodulator for application in functional foods.

Whole-genome assembly of Ganoderma leucocontextum (Ganodermataceae, Fungi) discovered from the Tibetan Plateau of China

Ganoderma leucocontextum, a newly discovered species of Ganodermataceae in China, has diverse pharmacological activities. G. leucocontextum was widely cultivated in southwest China, but the systematic genetic study has been impeded by the lack of a reference genome. Herein, we present the first whole-genome assembly of G. leucocontextum based on the Illumina and Nanopore platform from high-quality DNA extracted from a monokaryon strain (DH-8). The generated genome was 50.05 Mb in size with a N50 scaffold size of 3.06 Mb, 78,206 coding sequences and 13,390 putative genes. Genome completeness was assessed using the Benchmarking Universal Single-Copy Orthologs (BUSCO) tool, which identified 96.55% of the 280 Fungi BUSCO genes. Furthermore, differences in functional genes of secondary metabolites (terpenoids) were analyzed between G. leucocontextum and G. lucidum. G. leucocontextum has more genes related to terpenoids synthesis compared to G. lucidum, which may be one of the reasons why they exhibit different biological activities. This is the first genome assembly and annotation for G. leucocontextum, which would enrich the toolbox for biological and genetic studies in G. leucocontextum.

Purification, Physicochemical Properties, and Antioxidant Activities of Two Low-Molecular-Weight Polysaccharides from Ganoderma leucocontextum Fruiting Bodies

Two low-molecular-weight polysaccharides (GLP-1 and GLP-2) were purified from Ganoderma leucocontextum fruiting bodies, and their physicochemical properties and antioxidant activities were investigated and compared in this study. The results showed that GLP-1 and GLP-2 were mainly composed of mannose, glucose, galactose, xylose, and arabinose, with weight-average molecular weights of 6.31 and 14.07 kDa, respectively. Additionally, GLP-1 and GLP-2 had a similar chain conformation, crystal structure, and molecular surface morphology. Moreover, GLP-1 exhibited stronger antioxidant activities than GLP-2 in five different assays: 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), hydroxyl radical, superoxide anion radical, ferric reducing antioxidant power (FRAP), and oxygen radical antioxidant capacity (ORAC). The main linkage types of GLP-1 were found to be →4)-α-D-Glcp-(1→, →4)-β-D-Glcp-(1→, →3)-β-D-Glcp-(1→, →6)-β-D-Galp-(1→, →6)-α-D-Glcp-(1→, →4,6)-α-D-Glcp-(1→, and Glcp-(1→ by methylation analysis and nuclear magnetic resonance (NMR) spectroscopy. In addition, GLP-1 could protect NIH3T3 cells against tert-butyl hydroperoxide (tBHP)-induced oxidative damage by increasing catalase (CAT) and glutathione peroxidase (GSH-Px) activities, elevating the glutathione/oxidized glutathione (GSH/GSSG) ratio, and decreasing the malondialdehyde (MDA) level. These findings indicated that GLP-1 could be explored as a potential antioxidant agent for application in functional foods.

Eight new triterpenoids with inhibitory activity against HMG-CoA reductase from the medical mushroom Ganoderma leucocontextum collected in Tibetan plateau

Eight new triterpenoids, ganoleucoins T-Z(1-3, 5-8), and AA (9), together with eleven known triterpenes were isolated and identified from the wild fruiting bodies of the medicinal mushroom Ganoderma leucocontextum. The structures of new compounds were determined on the basis of NMR and MS spectral analysis. The inhibitory effects of 1-9 on HMG-CoA reductase were tested in vitro. Compounds 1, 7 and 8 showed significant HMG-CoA reductase inhibition with IC₅₀ values of 10.2, 9.72 and 8.68 μM, respectively. The other isolated compounds presented relatively weak inhibitory activity with IC₅₀ values >100 μM. Preliminary structure-activity relationship analysis showed that the HMG moiety in 7 and 8 contributed greatly to their inhibitory activity against HMG-CoA reductase. This work further demonstrates the mushroom G. leucocontextum to be valuable herbal medicine that deserves deep investigation.

Triterpenes and Meroterpenes with Neuroprotective Effects from Ganoderma leucocontextum

Ganoderma leucocontextum is a well-known medicinal mushroom cultivated in the Tibet Plateau of China. Chemistry investigation on the fruiting bodies of this mushroom resulted in the isolation of sixteen secondary metabolites including three new lanostane triterpenes, ganoleucoins Q - S (1 - 3), as well as thirteen known compounds (4 - 16). The structures of compounds 1 - 3 were determined by NMR, MS, CD spectral analysis, and chemical derivation method. The neuroprotective effects of compounds 1 - 16 were tested on PC12 cells. Compounds 1 and 2 showed protective effects against the H₂ O₂ induced damage with the survival rate of 83.19 ± 0.92%, 73.37 ± 1.25% at the concentration of 200 μm, respectively. Meanwhile, compounds 1 and 2 induced neurite outgrowth at 50 - 200 μm. The results from this study suggested that G. leucocontextum and its metabolites may be potential functional food ingredients for the prevention of neurodegenerative diseases.

Lanostane Triterpenoids from Fruiting Bodies of Ganoderma leucocontextum

Six new lanostane-type triterpenoids, namely leucocontextins S-X (1-6), together with twelve known compounds, were isolated from the fruiting bodies of Ganoderma leucocontextum. Their structures were established by MS and NMR data.

Leucocontextins A-R, lanostane-type triterpenoids from Ganoderma leucocontextum

Eighteen new lanostane-type triterpenoids, namely leucocontextins A-R (1-18) were isolated from the fruiting bodies of Ganoderma leucocontextum. Their structures were established by 1D and 2D NMR data in conjunction with HRESIMS/HREIMS, X-ray single crystal diffraction analysis. Compound 18 exhibited weak cytotoxicity against K562 and MCF-7 cell lines with IC50 of 20-30 μM.