Steroidal constituents of ganoderma applanatum and ganodermaneo-japonicum

Bibliometric, taxonomic, and medicinal perspectives of Ganoderma neo-japonicum Imazeki: A mini review

Ganoderma, a traditional medicine in Asian countries, has been used to prevent and treat various ailments for centuries. Ganoderma neo-japonicum (synonym Ganoderma bambusicola), also known as purple Lingzhi, is a species that is currently underutilised when compared to Ganoderma lucidum (Lingzhi). However, in recent decades, this mushroom has garnered significant attention due to its ethnomedicinal uses, especially in Southeast Asia regions like Malaysia. The taxonomy and nomenclature of this mushroom have been extensively studied. Numerous publications have reported that G. neo-japonicum displays a variety of medicinal properties, including antioxidation, anticancer, anti-hyperglycaemic, genoprotective, hepatoprotective, neuritogenic, and antidiabetic effects, both in vitro and in vivo. With the surge of research findings on this mushroom, this review aims to provide a systematic bibliometric analysis of G. neo-japonicum, published between 1991 to 2021. Additionally, the taxonomic description of this mushroom is discussed in detail. Our review reveals that G. neo-japonicum contains polysaccharides (α/β-D-glucans), triterpenoids, and sterols/ergosterol. However, the existing literature suggests that these active compounds have not yet been explored to their full potential as drug candidates. Moreover, most of the studies are preclinical and have several drawbacks. In conclusion, G. neo-japonicum possesses valuable pharmacological activities that merit further exploration.

The Artist's Conk Medicinal Mushroom Ganoderma applanatum (Agaricomycetes): Mycological, Mycochemical, and Pharmacological Properties: A Review

As a commonly used Chinese herbal medicine, Ganoderma applanatum (Pers.) Pat., also known as flat-ling Ganoderma (Chinese name bianlingzhi), old mother fungus (laomujun), and old ox liver (laoniugan), has high medicinal value. It is used as an anti-cancer drug in China and Japan. Besides, it can treat rheumatic tuberculosis and has the effect of relieving pain, clearing away heat, eliminating accumulation, stopping bleeding and eliminating phlegm. The purpose of this review is to analyze the research progress systematically and comprehensively in mycology, mycochemistry and pharmacological activities of G. applanatum, and discuss the prospect of prospective research and implementation of this medicinal material. A comprehensive literature search was performed on G. applanatum using scientific databases including Web of Science, PubMed, Google Scholar, CNKI, Elsevier. Collected data from different sources was comprehensively summarized for mycology, mycochemistry and pharmacology of G. applanatum. A total of 324 compounds were recorded, the main components of which were triterpenoids, meroterpenoids, steroids, and polysaccharides. G. applanatum and its active ingredients have a variety of pharmacological effects, including anti-tumor, liver protection, hypoglycemic, anti-fat, anti-oxidation, antibacterial and other activities. Although G. applanatum is widely used in traditional medicine and has diverse chemical constituents, more studies should be carried out in animals and humans to evaluate the cellular and molecular mechanisms involved in its biological activity.

Secondary Metabolites of Biscogniauxia: Distribution, Chemical Diversity, Bioactivity, and Implications of the Occurrence

The genus Biscogniauxia, a member of the family Xylariaceae, is distributed worldwide with more than 50 recognized taxa. Biscogniauxia species is known as a plant pathogen, typically acting as a parasite on tree bark, although certain members of this genus also function as endophytic microorganisms. Biscogniauxia endophytic strain has received attention in many cases, which includes constituent research leading to the discovery of various bioactive secondary metabolites. Currently, there are a total of 115 chemical compounds belonging to the class of secondary metabolites, and among these compounds, fatty acids have been identified. In addition, the strong pharmacological agents of this genus are (3aS,4aR,8aS,9aR)-3a-hydroxy-8a-methyl-3,5-dimethylenedecahydronaphto [2,3-b]furan-2(3H)-one (HDFO) (antifungal), biscopyran (phytotoxic activity), reticulol (antioxidant), biscogniazaphilone A and B (antimycobacterial), and biscogniauxone (Enzyme GSK3 inhibitor). This comprehensive research contributes significantly to the potential discovery of novel drugs produced by Biscogniauxia and holds promise for future development. Importantly, it represents the first-ever review of natural products originating from the Biscogniauxia genus.

Ganoderma lucidum: Current advancements of characteristic components and experimental progress in anti-liver fibrosis

Ganoderma lucidum (G. lucidum, Lingzhi) is a well-known herbal medicine with a variety of pharmacological effects. Studies have found that G. lucidum has pharmacological effects such as antioxidant, antitumor, anti-aging, anti-liver fibrosis, and immunomodulation. The main active components of G. lucidum include triterpenoids, polysaccharides, sterols, peptides and other bioactive components. Among them, the triterpenoids and polysaccharide components of G. lucidum have a wide range of anti-liver fibrotic effects. Currently, there have been more reviews and studies on the antioxidant, antitumor, and anti-aging properties of G. lucidum. Based on the current trend of increasing number of liver fibrosis patients in the world, we summarized the role of G.lucidum extract in anti-liver fibrosis and the effect of G. lucidum extract on liver fibrosis induced by different pathogenesis, which were discussed and analyzed. Research and development ideas and references are provided for the subsequent application of G. lucidum extracts in anti-liver fibrosis treatment.

A Review of Ganoderma Triterpenoids and Their Bioactivities

For centuries, Ganoderma has been used as a traditional medicine in Asian countries to prevent and treat various diseases. Numerous publications are stating that Ganoderma species have a variety of beneficial medicinal properties, and investigations on different metabolic regulations of Ganoderma species, extracts or isolated compounds have been performed both in vitro and in vivo. However, it has frequently been questioned whether Ganoderma is simply a dietary supplement for health or just a useful "medication" for restorative purposes. More than 600 chemical compounds including alkaloids, meroterpenoids, nucleobases, nucleosides, polysaccharides, proteins, steroids and triterpenes were extracted and identified from Ganoderma, with triterpenes serving as the primary components. In recent years, Ganoderma triterpenes and other small molecular constituents have aroused the interest of chemists and pharmacologists. Meanwhile, considering the significance of the triterpene constituents in the development of new drugs, this review describes 495 compounds from 25 Ganoderma species published between 1984 and 2022, commenting on their source, biosynthetic pathway, identification, biological activities and biosynthesis, together with applications of advanced analytical techniques to the characterization of Ganoderma triterpenoids.

Secondary Metabolites from Hericium erinaceus and Their Anti-Inflammatory Activities

Hericium erinaceus, a culinary and medicinal mushroom, is widely consumed in Asian countries. Chemical investigation on the fruiting bodies of Hericium erinaceus led to the isolation of one new ergostane-type sterol fatty acid ester, erinarol K (1); and eleven known compounds: 5α,8α -epidioxyergosta-6,22-dien-3β-yl linoleate (2); ethyl linoleate (3); linoleic acid (4); hericene A (5); hericene D (6); hericene E (7); ergosta-4,6,8(14),22-tetraen-3-one (8); hericenone F (9); ergosterol (10); ergosterol peroxide (11); 3β,5α,6α,22E-ergosta-7,22-diene-3,5,6-triol 6-oleate (12). The chemical structures of the compounds were determined by 1D and 2D NMR (nuclear magnetic resonance) spectroscopy, mass spectra, etc. Anti-inflammatory effects of the isolated aromatic compounds (5–7, 9) were evaluated in terms of inhibition of pro-inflammatory mediator (TNF-α, IL-6 and NO) production in lipopolysaccharide (LPS)-stimulated murine RAW 264.7 macrophage cells. The results showed that compounds 5 and 9 exhibited moderate activity against TNF-α (IC₅₀: 78.50 μM and 62.46 μM), IL-6 (IC₅₀: 56.33 μM and 48.50 μM) and NO (IC₅₀: 87.31 μM and 76.16 μM) secretion. These results supply new information about the secondary metabolites of Hericium erinaceus and their anti-inflammatory effects.

Induced production of steroids by co-cultivation of two endophytes from Mahonia fortunei

A new ergosterol derivative, 23R-hydroxy-(20Z,24R)-ergosta-4,6,8(14),20(22)-tetraen-3-one (1), and a biosynthetically related known compound, (22E,24R)-ergosta-4,6,8(14),22-tetraen-3-one (2), were isolated from the co-culture between endophytic fungus Pleosporales sp. F46 and endophytic bacterium Bacillus wiedmannii Com1 both inhibiting in the medicinal plant Mahonia fortunei. The structure of the new compound 1 was determined by extensive spectroscopic analysis using HRMS and NMR, together with the modified Mosher's ester method. This is the first example of isolation of a ergosterol derivative with a Δ²⁰⁽²²⁾-double bond in the side chain. Compound 1 exhibited moderate antibacterial efficacy against Staphylococcus aureus and no obvious cytotoxic activities against the cancer cell lines A549, MDA-MB-231 and Hct116. Our results not only reveal that compound 1 is a potent antibacterial lead compound, but also highlight the powder of co-cultivation for inducing the production of cryptic natural products from endophytes derived from the same host plant.

Aβ-42 lowering agents from the marine-derived fungus Dichotomomyces cejpii

The ascomycete Dichotomomyces cejpii was isolated from the marine sponge Callyspongia cf. C. flammea. Three new steroids (1-3), two of which are present as glycosides, with an untypical pattern of carbon-carbon double bounds, were obtained from fungal extracts, as well as the known xanthocillin X dimethyl ether (4). Compounds 2 and 4 were evaluated in an Alzheimer's disease cellular assay and found capable of preventing the enhanced production of amyloid β-42 in Aftin-5 treated cells. Aβ-42 lowering agents are considered as candidates for the treatment of neurodegenerative Alzheimer's disease.

Ganoderma neo-japonicum Imazeki revisited: Domestication study and antioxidant properties of its basidiocarps and mycelia

Mushroom cultivation benefits humankind as it deliberately encourages wild mushrooms to be commercially propagated while recycling agricultural wastes. Ganoderma neo-japonicum is a rare polypore mushroom found growing on decaying Schizostachyum brachycladium (a tropical bamboo) clumps in Malaysia. The Malaysian indigenous tribes including the Temuans and Temiars use the basidiocarps of G. neo-japonicum to treat various ailments including diabetes. In this study, the domestication of G. neo-japonicum in artificial logs of different agricultural residues was investigated. Sawdust promoted the mycelia spawn colonisation in the shortest period of 38 ± 0.5 days. However, only sawdust and bamboo dust supported the primodia formation. Complex medium supported mycelium growth in submerged cultures and 27.11 ± 0.43 g/L of mycelia was obtained after 2 weeks of cultivation at 28 °C and 200 rpm. Antioxidant potential in mushroom may be influenced by different cultivation and extraction methods. The different extracts from the wild and cultivated basidiocarps as well as mycelia were then tested for their antioxidant properties. Aqueous and ethanol extracts of mycelia and basidiocarps tested had varying levels of antioxidant activities. To conclude, domestication of wild G. neo-japonicum using agroresidues may ensure a continuous supply of G. neo-japonicum for its medicinal use while ensuring the conservation of this rare species.

Secondary metabolites from Ganoderma

Ganoderma is a genus of medicinal mushrooms. This review deals with secondary metabolites isolated from Ganoderma and their biological significance. Phytochemical studies over the last 40years led to the isolation of 431 secondary metabolites from various Ganoderma species. The major secondary compounds isolated are (a) C30 lanostanes (ganoderic acids), (b) C30 lanostanes (aldehydes, alcohols, esters, glycosides, lactones, ketones), (c) C27 lanostanes (lucidenic acids), (d) C27 lanostanes (alcohols, lactones, esters), (e) C24, C25 lanostanes (f) C30 pentacyclic triterpenes, (g) meroterpenoids, (h) farnesyl hydroquinones (meroterpenoids), (i) C15 sesquiterpenoids, (j) steroids, (k) alkaloids, (l) prenyl hydroquinone (m) benzofurans, (n) benzopyran-4-one derivatives and (o) benzenoid derivatives. Ganoderma lucidum is the species extensively studied for its secondary metabolites and biological activities. Ganoderma applanatum, Ganoderma colossum, Ganoderma sinense, Ganoderma cochlear, Ganoderma tsugae, Ganoderma amboinense, Ganoderma orbiforme, Ganoderma resinaceum, Ganoderma hainanense, Ganoderma concinna, Ganoderma pfeifferi, Ganoderma neo-japonicum, Ganoderma tropicum, Ganoderma australe, Ganoderma carnosum, Ganoderma fornicatum, Ganoderma lipsiense (synonym G. applanatum), Ganoderma mastoporum, Ganoderma theaecolum, Ganoderma boninense, Ganoderma capense and Ganoderma annulare are the other Ganoderma species subjected to phytochemical studies. Further phytochemical studies on Ganoderma could lead to the discovery of hitherto unknown biologically active secondary metabolites.

Applanatumin A, a new dimeric meroterpenoid from Ganoderma applanatum that displays potent antifibrotic activity

Applanatumin A (1), a novel meroterpenoid dimer, was isolated from the fungus Ganoderma applanatum. Its structure and absolute configuration were assigned on the basis of spectroscopic and computational data. Notably, 1 possesses a new hexacyclic skeleton containing a spiro[benzofuran-2,1'-cyclopentane] motif. A plausible pathway, involving a key Diels-Alder reaction, is proposed for the biosynthesis of 1. Applanatumin A exhibits potent antifibrotic activity in TGF-β1-induced human renal proximal tubular cells.

A comprehensive review of the structure elucidation and biological activity of triterpenoids from Ganoderma spp

Ganoderma triterpenes (GTs) are the major secondary metabolites of Ganoderma lucidum, a traditional Chinese medicine, popularly used for complementary cancer therapy. GTs are lanostane-tetracyclic triterpenes. They have been reported to possess anti-tumor, anti-inflammation, antioxidant, antimicrobial and blood fat reducing effects. To date, 316 GTs have been found and their similar chemical structures have proved difficult to elucidate. This paper compiles 316 naturally occurring triterpenes from Ganoderma based on the literature published through January 2013 along with their structures, physiological activities and 13C-NMR spectral data.

In vitro evaluation of the antioxidant and cytotoxic activities of constituents of the mangrove Lumnitzera racemosa Willd

This study performed phytochemical and bioactive assessments of the mangrove Lumnitzera racemosa Willd. leaves. Bioassay-guided fractionation of the methanolic extracts led to the identification of thirty-six compounds (1-36), their structures were elucidated using detailed NMR spectroscopic and MS analysis. The extracts, fractions, and the isolated compounds were screened for potential antioxidant and cytotoxic activities. Antioxidant assays were performed using peroxyl radical-scavenging and reducing assays, whereas cytotoxicity was measured using MTT assays in HL-60 and Hel-299 cell lines. The methanolic extract, CH2Cl2 and n-BuOH fractions (10.0 μg/mL) exhibited potent antioxidant activity, with Trolox equivalent (TE) values of 24.94 ± 0.59, 28.34 ± 0.20, and 27.09 ± 0.37 (μM), respectively. In addition, the isolated compounds exerted cytotoxic effects in a dose-dependent manner; compounds 1 and 14 exhibited the most potent cytotoxicity in HL-60 cells, with IC50 values of 0.15 ± 0.29 and 0.60 ± 0.16 μM, respectively. To clarify the mechanism(s) behind these cytotoxic effects, we measured the time-dependent changes in apoptotic markers including the condensation and fragmentation of nuclear chromatin, and the downregulation of p-ERK1/2, p-AKT, and c-Myc levels.

A PKS I gene-based screening approach for the discovery of a new polyketide from Penicillium citrinum Salicorn 46

Salicorn 46, an endophytic fungus isolated from Salicornia herbacea Torr., was identified as Penicillium citrinum based on its internal transcribed spacer and ribosomal large-subunit DNA sequences using a type I polyketide synthase (PKS I) gene screening approach. A new polyketide, penicitriketo (1), and seven known compounds, including ergone (2), (3β,5α,8α,22E)-5,8-epidioxyergosta-6,9,22-trien-3-ol (3), (3β,5α,8α,22E)-5,8-epidioxyergosta-6,22-dien-3-ol (4), stigmasta-7,22-diene-3β,5α,6α-triol (5), 3β,5α-dihydroxy-(22E,24R)-ergosta-7,22-dien-6β-yl oleate (6), N b-acetyltryptamine (7), and 2-(1-oxo-2-hydroxyethyl) furan (8), were isolated from the culture of Salicorn 46, and their chemical structures were elucidated by spectroscopic analysis. Antioxidant experiments revealed that compound 1 possessed moderate DPPH radical scavenging activity with an IC50 value of 85.33 ± 1.61 μM. Antimicrobial assays revealed that compound 2 exhibited broad-spectrum antimicrobial activity against Candida albicans, Clostridium perfringens, Mycobacterium smegmatis, and Mycobacterium phlei with minimal inhibitory concentration (MIC) values of 25.5, 25.5, 18.5, and 51.0 μM, respectively. Compound 3 displayed potent antimicrobial activities against C. perfringens and Micrococcus tetragenus with a MIC value of 23.5 μM. Compounds 5 and 6 showed high levels of selectivity toward Bacillus subtilis and M. phlei with MIC values of 22.5 and 14.4 μM, respectively. The results of this study highlight the use of PCR-based techniques for the screening of new polyketides from endophytic fungi containing PKS I genes.

Triterpenoids and steroids from Ganoderma mastoporum and their inhibitory effects on superoxide anion generation and elastase release

The methanol extracts of the fruiting bodies of Ganoderma mastoporum collected in Vietnam was purified to afford eight compounds, including three triterpenoids and five steroids. The purified compounds were examined for their inhibitory effects against superoxide anion generation and elastase release. Among the tested compounds, ergosta-4,6,8(14),22-tetraen-3-one (3) exhibited the most significant inhibition towards superoxide anion generation and elastase release with IC50 values of 2.30 ± 0.38 and 1.94 ± 0.50 µg/mL, respectively.

Phytochemical composition and toxicity of an antioxidant extract from Pimpinella brachycarpa (Kom.) Nakai

Pimpinella brachycarpa (Kom.) Nakai (PB) is one of the most favored edible greens grown in Asian regions. In our previously study, we found PB extract had antioxidant effects in vitro. In the present study, an EtOAc soluble extract (PBet) was isolated from PB. Then the antioxidant properties at cellular level, phytochemical composition and toxicity of PBet were examined. The results indicated that PBet (0.5-2mg/mL) could protect Bel-7404 cells from H(2)O(2) induced cell damage through scavenging of intracellular ROS. Moreover, myristic acid, 24ζ-methyl-5α-lanosta-25-one, β-sitosterol, pregnenolone and β-daucosterol were firstly isolated from PB. In addition, PBet (0.75g/kg BW, ig) had no acute toxicity and it (0.03-0.12g/kg BW, ig, 7 d) could not influence the rate of bone marrow polychromatic erythrocytes micronucleus and chromosome aberration in KM mice. All above findings suggested that PBet could be considered as a safe functional food with antioxidant activities.

Cytotoxic steroids from Monascus purpureus-fermented rice

Bioassay-guided fractionation of an EtOH extract of Monascus purpureus-fermented rice led to the isolation of two new steroids (22S, 23R, 24S)-20β,23α,25α-trihydroxy-16,22-epoxy-4,6,8(14)-trienergosta-3-one (1), the first example of a steroid possessing both a conjugated triene ketone system and a fused 4H-furan ring side chain within one molecule, and (22E, 24R)-3β,5α-dihydroxyergosta-23-methyl-7,22-dien-6-one (2), as well as two known compounds (22E, 24R)-3β,5α-dihydroxyergosta-7,22-dien-6-one (3) and (22E, 24R)-6β-methoxy-ergosta-7,22-diene-3β,5α-diol (4). Their structures were assigned by detailed interpretation of HRESIMS, 1D and 2D NMR spectroscopic data. The absolute stereochemistry of 1 was determined by single-crystal X-ray crystallography while the absolute stereochemistry of 2 was established by CD. Compounds 1-4 showed cytotoxic activity against the lung adenocarcinoma (A549) with IC(50) values of 0.08, 0.94, 12.6 and 13.5 μM, respectively. In addition, compounds 1 and 2 exhibited moderate activities against human ovarian cancer (A2780), with IC(50) values of 2.8 and 5.1 μM.

bis-Sigmodiol: a new prenylflavanone dimer from Erythrina sigmoidea Hua (Fabaceae) of Nigeria

A new prenylflavanone dimer named bis-sigmodiol was isolated from Erythrina sigmoidea, along with six known constituents isobavachin, lupiwighteone, orientanol A, ergosta-4, 6, 8 (14), 22-tetraen-3-one, lupenyl acetate, and p-hydroxybenzoic acid. These known constituents have not been reported so far from E. sigmoidea. Their structures were elucidated by spectroscopic methods.

Antiinflammatory triterpenoids and steroids from Ganoderma lucidum and G. tsugae

The antiinflammatory properties of triterpenoids and steroids from both Ganoderma lucidum and Ganoderma tsugae were studied. Twelve compounds, including ergosta-7,22-dien-3beta-ol (1), ergosta-7,22-dien-3beta-yl palmitate (2), ergosta-7,22-dien-3-one (3), ergosta-7,22-dien-2beta,3alpha,9alpha-triol (4), 5alpha,8alpha-epidioxyergosta-6,22-dien-3beta-ol (5), ganoderal A (6), ganoderal B (7), ganoderic aldehyde A (8), tsugaric acid A (9), 3-oxo-5alpha-lanosta-8,24-dien-21-oic acid (10), 3alpha-acetoxy-5alpha-lanosta-8,24-dien-21-oic acid ester beta-d-glucoside (11), and tsugaric acid B (12), were assessed in vitro by determining their inhibitory effects on the chemical mediators released from mast cells, neutrophils, and macrophages. Compound 10 showed a significant inhibitory effect on the release of beta-glucuronidase from rat neutrophils stimulated with formyl-Met-Leu-Phe (fMLP)/cytochalasin B (CB) whereas compound 9 significantly inhibited superoxide anion formation in fMLP/CB-stimulated rat neutrophils. Compound 10 also exhibited a potent inhibitory effect on NO production in lipopolysaccharide (LPS)/interferon-gamma (IFN-gamma)-stimulated N9 microglial cells. Moreover, compound 9 was also able to protect human keratinocytes against damage induced by ultraviolet B (UV B) light, which indicated 9 could protect keratinocytes from photodamage.

Lignans, an amide and anti-platelet activities from Piper philippinum

Investigation of the stem extract of Piper philippinum led to isolation of eight compounds, piperphilippinins I-VI (1-6), philippinamide (7), and (+)-bornyl caffeate (8), together with 26 known compounds. Among the isolates, (-)-3',4'-O,O-demethylenehinokinin (10) and 3,4-methylenedioxycinnamaldehyde (23) showed anti-platelet activities in vitro.

5alpha,8alpha-Epidioxy-22E-ergosta-6,9(11),22-trien-3beta-ol from an edible mushroom suppresses growth of HL60 leukemia and HT29 colon adenocarcinoma cells

We purified a sterol with antitumor activity from the edible mushroom Sarcodon aspratus (BERK.) S. ITO and identified it as 5alpha,8alpha-epidioxy-22E-ergosta-6,9(11),22-trien-3beta-ol (9,11-dehydroergosterol peroxide (9(11)-DHEP)). Purified 9(11)-DHEP was a more effective inhibitor of HL60 leukemia cell growth and stronger apoptosis-inducer than 5alpha,8alpha-epidioxy-22E-ergosta-6,22-dien-3beta-ol (ergosterol peroxide (EP)) that we had previously identified as an apoptosis inducer. Moreover, 9(11)-DHEP selectively suppressed the growth of HT29 human colon adenocarcinoma cells but not WI38 normal human fibroblasts. After 5 d incubation of HT29 with 7 microM 9(11)-DHEP, the number of S phase cells decreased from 23 to 15% of total diploid cells and 17% became hypodiploid. Expression of the cyclin-dependent kinase inhibitor 1A (p21, WAF1, Cip1) (CDKN1A), which has been shown to cause cell cycle arrest and apoptosis in HT29 cells, was induced by 9(11)-DHEP. These results suggest that 9(11)-DHEP inhibits HT29 cell growth by inducing CDKN1A expression, thus causing cell cycle arrest and apoptosis.

Six Immunosuppressive Features from an Ascomycete, Zopfiella ion gicaudata, Found in a Screening Study Monitored by Immunomodulatory Activity

In a screening study on immunomodulatory fungal metabolites, three known anthraquinones, carviolin (roseo-purpurin) (1), 1-O-methylemodin (2), omega-hydroxyemodin (citreorosein) (4), and a new anthraquinone, omega-acetylcarviolin (3), together with a known steroid, ergosta-4,6,8(14),22-tetraen-3-one (5) and a new steroid, 25-hydroxyergosta-4,6,8(14),22-tetraen-3-one (6) were isolated from an Ascomycete, Zopfiella longicaudata, and found to have moderate immunosuppressive activities. The structure-activity relationships of these metabolites are discussed.