Antineoplastic agents. 556. Isolation and structure of Coprinastatin 1 from Coprinus cinereus

Synthesis of Coprinol and Several Alcyopterosin Sesquiterpenes by Regioselective [2 + 2 + 2] Alkyne Cyclotrimerization

Alkyne [2 + 2 + 2] cyclotrimerization is a strategically attractive but tactically challenging approach to the synthesis of highly substituted benzene rings. Here, a bimolecular regioselective cyclotrimerization is applied to the total synthesis of the natural product coprinol and several related alcyopterosins from the illudalane family of sesquiterpenes. The synthesis of coprinol from dimedone was completed in six steps and a 57% overall yield. Alternative functional group manipulations lead to alcyopterosins A, B, and O and two additional congeners, all within six steps.

New antioxidants from the culture broth of Coprinopsis echinospora

During the search for natural antioxidants from fungal metabolites, three new sesquiterpene derivatives (1-3) have been isolated from the culture broth of Coprinopsis echinospora. Their structures were determined by spectroscopic methods, mainly NMR and mass spectrometric analyses. These compounds exhibited antioxidant activity with IC₅₀ values in the range of 34.4-144.5 μM in the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical-scavenging assay.

Rhizophins A and B, new sesquiterpenes from the culture broth of Coprinus rhizophorus

Two new sesquiterpenes (1 and 2) together with one known compound (3) were isolated from the culture broth of Coprinus rhizophorus. Chemical structures of these compounds were deduced by spectroscopic methods. Compound 1 exhibited free-radical-scavenging activity against the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical. Compounds 2 and 3 exhibited antimicrobial activities against Saccharomyces cerevisiae, Propionibacterium acnes, and Staphylococcus epidermidis.

Protoilludane, Illudalane, and Botryane Sesquiterpenoids from the Endophytic Fungus Phomopsis sp. TJ507A

To explore the chemical diversity of metabolites from endophytic fungi, the strain Phomopsis sp. TJ507A, isolated from the medicinal plant Phyllanthus glaucus, was investigated. A 2,3- seco-protoilludane-type sesquiterpenoid (1), eight protoilludane-type sesquiterpenoids (2-9), four illudalane-type sesquiterpenoids (10a/10b, 11, and 12), and a botryane-type sesquiterpenoid (13) in addition to seven known sesquiterpenoids (14-20) were identified from the liquid culture of the fungus. Structures of the isolated compounds, including their absolute configurations, were elucidated based on extensive spectroscopic analyses, a modified Mosher analysis, electronic circular dichroism (ECD) calculations, and [Rh₂(OCOCF₃)₄]-induced ECD spectra as well as X-ray crystallographic analyses. Compound 1 represents the first example of a naturally occurring sesquiterpenoid containing the unusual 2,3- seco-protoilludane scaffold. Compounds 1 ( p < 0.001); 2-6, 15, and 18 ( p < 0.01); and 7, 9, and 20 ( p < 0.05) displayed β-site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibitory activities ranging from 19.4% to 43.8% at the concentration of 40 μM. LY2811376 was used as the positive control with an inhibitory activity of 38.6% ( p < 0.01). Furthermore, none of these compounds showed obvious hepatotoxicity at concentration of 40 μM.

Total Synthesis of Coprinol

The first synthesis of coprinol has been achieved from 2-methoxy-3,5-dimethylbenzaldehyde via the intermediacy of an indanone derivative where dialkylation, Friedel-Crafts acylation, demethylation, and regioselective formation of a primary -OH group from a chloroacetyl group are the key steps.

Overproduction of geranylgeraniol in Coprinopsis cinerea by the expression of geranylgeranyl diphosphate synthase gene

(E, E, E)-Geranylgeraniol (GGOH) is a valuable ingredient of many perfumes and a valuable precursor for synthesizing pharmaceuticals. In an attempt to increase the GGOH concentration in Coprinopsis cinerea, we demonstrated that the expression of geranylgeranyl diphosphate synthase (ggpps) gene isolated from Taxus x media could promote GGOH production. Furthermore, the concentrations of squalene and ergosterol were measured in the engineered strains. Expectedly, significant decreases of squalene and ergosterol levels were observed in those strains transformed with ggpps gene. This could be explained by the partial redirection of metabolic flux from squalene to GGOH, whose biosynthesis competes for the same precursor with squalene. This work suggested that the expression of ggpps in higher fungi was an effective method for bio-production of GGOH.

Sterostreins F-O, illudalanes and norilludalanes from cultures of the Basidiomycete Stereum ostrea BCC 22955

Sterostreins F-O (1-10), 10 illudalanes and norilludalanes, were isolated from cultures of the Basidiomycete Stereum ostrea BCC 22955. Their structures were elucidated by analyses of the NMR spectroscopic and mass spectrometry data. Sterostreins M (8), N (9), and O (10) are pyridine-containing illudalanes.

Guanacastane-type diterpenoids with cytotoxic activity from Coprinus plicatilis

Four new guanacastane-type diterpenoids (1-4), together with the known compound, guanacastepene E (5), were isolated from a basidiomycete of the macro-fungi, Coprinus plicatilis 82. Their structures were elucidated on the basis of extensive spectroscopic analyses, including FT-ICR-MS, UV, IR and 1D and 2D NMR experiments. The in vitro cytotoxic activities of all compounds against the human cancer cell lines HepG2, HeLa, MDA-MB-231, BGC-823, HCT 116, and U2OS were evaluated, only compound 1 exhibited significant cytotoxicities with IC(50) values ranging from 1.2 to 6.0 μM.

Unusual illudin-type sesquiterpenoids from cultures of Agrocybe salicacola

Seven new illudin-type sesquiterpenoids, agrocybins A–G (1–7), along with three known analogues (8–10), have been isolated from the culture broth of the fungus Agrocybe salicacola. Their structures were elucidated on the basis of extensive spectroscopic data analysis and comparison with data reported in the literature. The relative stereoconfigurations of 1 and 6 were elucidated by the X-ray crystallographic diffraction analysis. Compound 1 was highly cyclized containing seven chiral carbons which arranged compactly in six rings.

Sterostreins A-E, new terpenoids from cultures of the Basidiomycete Stereum ostrea BCC 22955

Sterostreins A-E (1, 2, 3a/3b, 4, and 5), five novel terpenoids, were isolated from cultures of the mushroom fungus Stereum ostrea BCC 22955. Sterostrein A (1) exhibited antimalarial activity (IC(50) 2.3 μg/mL) and cytotoxicity (IC(50) 5.3-38 μg/mL).

Antineoplastic agents 582. Part 1: Isolation and structure of a cyclobutane-type sesquiterpene cancer cell growth inhibitor from Coprinus cinereus (Coprinaceae)

Bioassay-guided (murine P388 lymphocytic leukemia and human cancer cell lines) separation of an ethyl acetate extract prepared from the inky cap fungus Coprinus cinereus led to the isolation of three new sesquiterpenes, 7,7a-diepicoprinastatin 1 (1), 14-hydroxy-5-desoxy-2S,3S,9R-illudosin (2), and 4,5-dehydro-5-deoxyarmillol (3), together with the known armillol (4). The structure and relative configuration of 1 was determined by single-crystal X-ray diffraction experiments. The structures of compounds 2, 3, and 4 were each deduced by a combination of HRMS and 1D and 2D NMR techniques. Cyclobutane 2 led to modest inhibition of the murine P388 leukemia cell line.