Insights into Ganoderma fungi meroterpenoids opening a new era of racemic natural products in mushrooms

Ganoderma meroterpenoids (GMs) containing 688 structures to date were discovered to have multiple remarkable biological activities. 65.6% of meroterpenoids featuring stereogenic centers from Ganoderma species are racemates. Further, GMs from different Ganoderma species seem to have their own characteristics. In this review, a comprehensive summarization of GMs since 2000 is presented, including GM structures, structure corrections, biological activities, physicochemical properties, total synthesis, and proposed biosynthetic pathways. Additionally, we especially discuss the racemic nature, species-related structural distribution, and structure-activity relationship of GMs, which will provide a likely in-house database and shed light on future studies on GMs.

Ganoderma lucidum-Derived Meroterpenoids Show Anti-Inflammatory Activity In Vitro

Ganoderma lucidum, known as the "herb of spiritual potency", is used for the treatment and prevention of various diseases, but the responsible constituents for its therapeutic effects are largely unknown. For the purpose of obtaining insight into the chemical and biological profiling of meroterpenoids in G. lucidum, various chromatographic approaches were utilized for the title fungus. As a result, six undescribed meroterpenoids, chizhienes A-F (1-6), containing two pairs of enantiomers (4 and 5), were isolated. Their structures were identified using spectroscopic and computational methods. In addition, the anti-inflammatory activities of all the isolates were evaluated by Western blot analysis in LPS-induced macrophage cells (RAW264.7), showing that 1 and 3 could dose dependently inhibit iNOS but not COX-2 expression. Further, 1 and 3 were found to inhibit nitric oxide (NO) production using the Greiss reagent test. The current study will aid in enriching the structural and biological diversity of Ganoderma-derived meroterpenoids.

Lanostane triterpenoids with anti-proliferative and PTP1B/α-glucosidase inhibitory activities from the fruiting bodies of Ganoderma calidophilum

Twelve previously undescribed and four known lanostane triterpenoids were isolated from the fruiting bodies of Ganoderma calidophilum. The structures of undescribed compounds, ganodecalones H-S (1-12), were elucidated by extensive spectroscopic analysis as well as ECD and NMR calculations. Compound 4 showed significant inhibitory activity against human leukaemia cell line K562, gastric cancer cell line SGC-7901, and cervical cancer cell line HeLa with IC50 values of 13.10 ± 0.19, 17.26 ± 4.75, and 4.36 ± 0.58 μM, respectively. Compound 16 exhibited inhibitory potency against protein tyrosine phosphatase 1B (PTP1B) and α-glucosidase with IC50 values of 30.2 ± 0.13 μM and 120.6 ± 0.14 μM, respectively. The binding sites and interactions of 16 with PTP1B and α-glucosidase were revealed using molecular docking simulations.

Sources, Transformations, Syntheses, and Bioactivities of Monoterpene Pyridine Alkaloids and Cyclopenta[c]pyridine Derivatives

Monoterpene pyridine alkaloids (MTPAs) are alkaloids derived from iridoid glycosides (IGs). The common molecular structure of MTPAs is the pyridine ring, while some of them have a cyclopenta[c]pyridine skeleton. Some compounds containing this structure are potentially bioactive medicinal agents. In this paper, seven drug candidates (A-G), ninety natural source products (1-90), thirty-seven synthesized compounds (91-127), as well as twenty-six key intermediates (S1-S26) were summarized. We categorized five types of MTPAs and one type of cyclopenta[c]pyridine alkaloids in all. Additionally, their possible genetic pathways were proposed. Then, the chemical transformation, biotransformation, chemical synthesis, as well as the bioactivity of MTPAs and cyclopenta[c]pyridine derivatives were analyzed and summarized. Cyclopenta[c]pyridine derivatives can be concisely and chirally synthesized, and they have shown potentials with antibacterial, insecticidal, antiviral, anti-inflammatory, and neuropharmacological activities.

Lanostane Triterpenoids and Ergostane Steroids from Ganoderma luteomarginatum and Their Cytotoxicity

Macrofungus Ganoderma luteomarginatum is one of the main species of Ganoderma fungi distributed in Hainan province of China, the fruiting bodies of which have been widely used in folk as a healthy food to prevent tumors. To explore the potential cytotoxic constituents from G. luteomarginatum, the phytochemical investigation on the ethyl acetate soluble fraction of 95% ethanolic extract from the fruiting bodies of this fungus led to the isolation of twenty-six lanostane triterpenoids (1–26), including three undescribed ones (1–3), together with eight ergostane steroids (27–34). The structures of three new lanostane triterpenoids were elucidated as lanosta-7,9(11)-dien-3β-acetyloxy-24,25-diol (1), lanosta-7,9(11)-dien-3-oxo-24,26-diol-25-methoxy (2), and lanosta-8,20(22)-dien-3,11,23-trioxo-7β,15β-diol-26-oic acid methyl ester (3) by the analysis of 1D, 2D NMR, and HRESIMS spectroscopic data. All isolates were assayed for their cytotoxic activities using three human cancer cell lines (K562, BEL-7402, and SGC-7901) and seven lanostane triterpenoids (1, 2, 7, 13, 18, 22, and 24), and one ergostane steroid (34) showed definite cytotoxicity with IC₅₀ values that ranged from 6.64 to 47.63 μg/mL. Among these cytotoxic lanostane triterpenoids, compounds 2 and 13 showed general cytotoxicity against three human cancer cell lines, while compounds 1 and 18 exhibited significant selective cytotoxicity against K562 cells with IC₅₀ values of 8.59 and 8.82 μg/mL, respectively. Furthermore, the preliminary structure–cytotoxicity relationships was proposed.

Discovery of antibacterial agents targeting biofilm formation: total synthesis and in vitro investigation of amycolasporins

Three monoterpene alkaloids amycolasporin A and (±) amycolasporins B and C have been synthesized for the first time from commercially available materials in yields of 31%, 14% and 21%, respectively. Their six analogues (18, 19, 30a and 30d-30f) were synthesized through a similar protocol. Meanwhile, the antibacterial activity of all synthesized molecules was evaluated, showing different levels of bioactivity. Among them, analogue 30d was screened as the most effective antibacterial candidate against E. coli (MIC value, 12.5 μg mL^-1) and S. aureus (MIC value, 12.5 μg mL^-1). Further investigation showed that 30d obviously inhibited biofilm formation and disrupted the preformed biofilm of E. coli and S. aureus by promoting intracellular ROS release.

Structures and Biological Activities of Alkaloids Produced by Mushrooms, a Fungal Subgroup

Alkaloids are a wide family of basic N-containing natural products, whose research has revealed bioactive compounds of pharmacological interest. Studies on these compounds have focused more attention on those produced by plants, although other types of organisms have also been proven to synthesize bioactive alkaloids, such as animals, marine organisms, bacteria, and fungi. This review covers the findings of the last 20 years (2002–2022) related to the isolation, structures, and biological activities of the alkaloids produced by mushrooms, a fungal subgroup, and their potential to develop drugs and agrochemicals. In some cases, the synthesis of the reviewed compounds and structure−activity relationship studies have been described.

Meroterpenoids With Protein Tyrosine Phosphatase 1B Inhibitory Activities From the Fruiting Bodies of Ganoderma ahmadii

Ganoderma fungi have long been used as functional foods and traditional medicines in Asian countries. Ganoderma ahmadii is one of the main species of Ganoderma fungi distributed in Hainan province of China, the fruiting bodies of which have been used in folk to lower blood sugar for a long time. A chemical investigation of the fruiting bodies of Ganoderma ahmadii led to the isolation of seven new meroterpenoids, named ganoduriporols F-L (1–7). The chemical structures of the compounds were elucidated by spectroscopic data including HRESIMS and 2D NMR. Compounds 5–7 represent the first examples of ganoduriporol-type meroterpenoids bearing oxepane rings in their skeletons. Compounds 1–4 showed inhibitory activity against protein tyrosine phosphatase 1B (PTP1B) comparable to the positive control Na₃VO₄, with IC₅₀ values of 17, 20, 19, and 23 μM, respectively.

Altertoxins with Quorum Sensing Inhibitory Activities from The Marine-Derived Fungus Cladosporium sp. KFD33

Five new perylenequinone derivatives, altertoxins VIII–XII (1–5), as well as one known compound cladosporol I (6), were isolated from the fermentation broth of the marine-derived fungus Cladosporium sp. KFD33 from a blood cockle from Haikou Bay, China. Their structures were determined based on spectroscopic methods and ECD spectra analysis along with quantum ECD calculations. Compounds 1–6 exhibited quorum sensing inhibitory activities against Chromobacterium violaceum CV026 with MIC values of 30, 30, 20, 30, 20 and 30 μg/well, respectively.

Triterpene-farnesyl hydroquinone conjugates from Ganoderma calidophilum

Two new lanostane-type triterpenoids characterized with farnesyl hydroquinone moieties, ganocalidoins A (1) and B (2), were isolated from the fruiting body of Ganoderma calidophilum, together with two known tripterpenes (3-4). The structures of compounds 1 and 2 were determined by extensive spectroscopic data including HRESIMS, 1D and 2D NMR. Ganocalidoins A and B showed anti-oxidant capacity with IC₅₀ values of 38.7 ± 2.8 and 34.2 ± 1.8 μM, respectively. The compounds did not show tyrosinase inhibition activity.

Lanostane triterpenoids from Ganoderma luteomarginatum and their cytotoxicity against four human cancer cell lines

Lanostane triterpenoids are major metabolites of macrofungi from the genus Ganoderma and possess enormous substitution diversity and remarkable biological activities, especially anticancer, antioxidant, and anti-inflammatory effects. The present phytochemical investigation resulted in the isolation of nine undescribed lanostane triterpenoids and five known analogues from the fruiting bodies of Ganoderma luteomarginatum, which was first phytochemically studied by our group. Chemical structures were elucidated based on spectroscopic evidence. (5α,23E)-27-nor-lanosta-8,23-dien-3,7,25-trione and (5α,23E)-27-nor-3β-hydroxylanosta-8,23-dien-7,25-dione are undescribed triterpenoids with an unusual 27-nor-lanostane carbon skeleton. All isolates were assayed for their cytotoxic activities using four human cancer cell lines (HGC-27, HeLa, A549, and SMMC-7721) and one human normal cell line (LO2), and the structure-cytotoxicity relationships were preliminarily explored. (5α,24E)-3β-acetoxyl-26-hydroxylanosta-8,24-dien-7-one exhibited the highest cytotoxicity against HeLa and A549 cell lines, with IC₅₀ values of 1.29 and 1.50 μM, respectively.

Cytotoxic and N-Acetyltransferase Inhibitory Meroterpenoids from Ganoderma cochlear

Seven compounds, including two pairs of new meroterpenoids, (+)- and (−)-gancochlearol C (1), (+)- and (−)-cochlearoid Q (3), and a new meroterpenoid gancochlearol D (2), together with four known meroterpenoids were isolated from the aqueous EtOH extract of the fruiting bodies of Ganoderma cochlear. Their structures were determined by spectroscopic data. The isolated compounds were evaluated for their cytotoxic activity against three human lung cancer cells (H1975, PC9, A549) and N-acetyltransferase inhibitory property. The results show that (+)-gancochlearol C could inhibit N-acetyltransferase with an IC₅₀ value of 5.29 μM. In addition, ganomycin F was found to show moderate activity against the H1975 human lung cancer cell line, with an IC₅₀ value of 19.47 μM.

Meroterpenoids from Ganoderma Species: A Review of Last Five Years

Meroterpenoids are hybrid natural products that partially originate from the terpenoid pathway. Ganoderma meroterpenoids (GMs) are a type of meroterpenoids containing a 1,2,4-trisubstituted phenyl and a polyunsaturated terpenoid part. Over last 5 years, great efforts have been made to conduct phytochemistry research on the genus Ganoderma, which have led to the isolation and identification of a number of GMs. These newly reported GMs showed diverse structures and a wide range of biological activities. This review gives an overview of new GMs from genus Ganoderma and their biological activities and biosynthetic pathway, focusing on the period from 2013 until 2018.

Two new farnesyl phenolic compounds with anti-inflammatory activities from Ganoderma duripora

Ganoderma fungi have long been used as a famous traditional medicine and food in country of East Asia. In this work, two new farnesyl phenolic compounds, ganoduriporols A and B (1 and 2), were isolated from the fruiting bodies of Ganoderma duripora, and their structures were elucidated using various spectroscopic methods. Anti-inflammatory activities were assayed and evaluated for the two compounds. Ganoduriporols A and B exhibited dose-dependent anti-inflammatory effects in RAW 264.7 cells. Furthermore, ganoduriporol A was demonstrated to inhibit the production of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6) and prostaglandin E₂ (PGE₂) through the suppression of COX-2, MAPK and NF-κB signaling pathway in LPS-induced macrophage cells. These results suggested that these two new farnesyl phenolic compounds and the fruiting body of G. duripora could serve as anti-inflammatory agents for medicinal use or functional food.

Total Syntheses and Biological Evaluation of the Ganoderma lucidum Alkaloids Lucidimines B and C

Although a range of pharmacologically active compounds has been obtained from the mycelium and fruiting bodies of Ganoderma lucidum, the biological properties of the alkaloids present in this functional food remain unknown. Herein, we report total syntheses of lucidimines B and C, key members of the first family of alkaloids isolated from G. lucidum, and the evaluation of these synthetically derived materials as antioxidants and antiproliferative agents. Lucidimine B proved to be a better antioxidant than congener C. Similarly, lucidimine B exhibited antiproliferative properties toward MCF-7 cells (an EC50 value of 0.27 ± 0.02 μmol/mL), whereas lucidimine C was inactive. The former alkaloid arrested the MCF-7 cell cycle in the S phase by inducing DNA fragmentation, hence reducing the mitochondrial membrane potential. This work thus demonstrates, for the first time, that the alkaloidal constituents derived from G. lucidum are biologically active and may, therefore, contribute to the beneficial health claims made for this nutraceutical.

Lanostane-type triterpenoids from the fruiting body of Ganoderma calidophilum

To search for active anti-cancer constituents in the fruiting body of Ganoderma calidophilum, we have successfully isolated four previously undescribed spiro-lactone lanostane triterpenoids (spiroganocalitones A-D), two previously undescribed lanostanoids (ganodecalones A and B) together with twenty-three known ones. The structures of the six previously undescribed compounds were elucidated based on 1D, 2D-NMR, and HRMS analyses. Ganoderone A showed moderate cytotoxic activity against K562, BEL7402, and SGC790 cell lines with IC₅₀ values of 7.62, 6.28, and 3.55 μM, respectively.

Shushe Acids A-D from Ganoderma Applanatum

Ganoderma applanatum is a fungus used for the prevention and treatment of a variety of disorders in China. In the present study, four new compounds, named shushe acids A-D (1-4), were isolated from the fruiting bodies of this species. Their structures were identified on the basis of spectroscopic methods. Compounds 1-4 are all natural product hybrids composed of derivatives of gallic acid, glycerol and succinic acid. None of the four compounds showed activity against the MCF-7 cell line.

Development of Ling-zhi industry in China - emanated from the artificial cultivation in the Institute of Microbiology, Chinese Academy of Sciences (IMCAS)

Ling-zhi is a medicinal herb that generally refers to a fungus in the genus Ganoderma. It has been used as a medicinal mushroom in traditional Chinese medicine for more than 2000 years. Mycologists at the Institute of Microbiology, Chinese Academy of Sciences (IMCAS) first artificially cultivated the Ling-zhi fruiting body in the late 1960s (X.J. Liu's team). In IMCAS, different research teams have extensively studied Ling-zhi in the aspects of national resource surveys, systematic taxonomy, chemical analysis, and processing for medicinal and health applications. The research results from IMCAS have provided essential support and prompted the development of the Ling-zhi industry in China to some extent. This review aims to summarize the history of research on Ling-zhi in IMCAS and its role in the development of the Ling-zhi economy.