Search Results (6)

The Arctic-derived fungus Eutypella sp. D-1 can produce numerous secondary metabolites, and some compounds exhibit excellent biological activity. Seven pimarane-type diterpenes, including three new compounds eutypellenone F (1), libertellenone Y (2), and libertellenone Z (3), and four known compounds (4–7), were isolated from fermentation broth of Eutypella sp. D-1 by the OSMAC strategy of adding ethanol as a promoter in the culture medium. Compound 2 has a rare tetrahydrofuran-fused pimarane diterpene skeleton. The anti-inflammatory activity of all compounds was evaluated. Compounds 3–6 showed a significant inhibitory effect on cell NO release at 10 μmol/L by in vitro experiments, of which 3–5 had inhibitory rates over 60% on nitric oxide (NO) release. Subsequently, the anti-inflammatory activity of 3–5 was evaluated based on a zebrafish model, and the results showed that 3 had a significant inhibitory effect on inflammatory cells migration at 40 μmol/L, while 4 and 5 had a significant inhibitory effect at 20 μmol/L. Moreover, compounds 3–5 have the same conjugated double bond structure, which may be an important group for these compounds to exert anti-inflammatory activity. Full article

A chemical investigation of the Arctic-derived fungus Eutypella sp. D-1 based on the OSMAC (one strain many compounds) approach resulted in the isolation of five cytosporin polyketides (compounds 1–3 and 11–12) from rice medium and eight cytosporins (compounds 2 and 4–11) from solid defined medium. The structures of the seven new compounds, eutypelleudesmane A (1), cytosporin Y (2), cytosporin Z (3), cytosporin Y₁ (4), cytosporin Y₂ (5), cytosporin Y₃ (6), and cytosporin E₁ (7), were elucidated by analyzing their detailed spectroscopic data. Structurally, cytosporin Y₁ (4) may be a key intermediate in the biosynthesis of the isolated cytosporins, rather than an end product. Compound 1 contained a unique skeleton formed by the ester linkage of two moieties, cytosporin F (12) and the eudesmane-type sesquiterpene dihydroalanto glycol. Additionally, the occurrence of cyclic carbonate moieties in compounds 6 and 7 was found to be rare in nature. The antibacterial, immunosuppressive, and cytotoxic activities of all compounds derived from Eutypella sp. D-1 were evaluated. Unfortunately, only compounds 3, 6, 8, and 10–11 displayed immunosuppressive activity, with inhibitory rates of 62.9%, 59.5%, 67.8%, 55.8%, and 68.7%, respectively, at a concentration of 5 μg/mL. Full article

Libertellenone H (LH), a marine-derived pimarane diterpenoid isolated from arctic fungus Eutypella sp. D-1, has shown effective cytotoxicity on a range of cancer cells. The present study is to explore the anticancer effect of LH on human pancreatic cancer cells and to investigate the intracellular molecular target and underlying mechanism. As shown, LH exhibited anticancer activity in human pancreatic cancer cells by promoting cell apoptosis. Mechanistic studies suggested that LH-induced reactive oxygen species (ROS) accumulation was responsible for apoptosis as antioxidant N-acetylcysteine (NAC) and antioxidant enzyme superoxide dismutase (SOD) antagonized the inhibitory effect of LH. Zymologic testing demonstrated that LH inhibited Trx system but had little effect on the glutathione reductase and glutaredoxin. Mass spectrometry (MS) analysis revealed that the mechanism of action was based on the direct conjugation of LH to the Cys³²/Cys³⁵ residue of Trx1 and Sec⁴⁹⁸ of TrxR, leading to a decrease in the cellular level of glutathione (GSH) and activation of downstream ASK1/JNK signaling pathway. Taken together, our findings revealed LH was a marine derived inhibitor of Trx system and an anticancer candidate. Full article

Eutypella parasitica R.W. Davidson and R.C. Lorenz is the causative agent of Eutypella canker of maple, a destructive disease of maples in Europe and North America. The fungus E. parasitica infects the trunk through a branch stub or bark wound. Because the fungal community may have an impact on infection and colonization by E. parasitica, the composition of fungi colonizing wood of dead branches of sycamore maple (Acer pseudoplatanus L.) was investigated in five sampling sites in Slovenia. Forty samples from each sampling site were collected between the November 2017 and March 2018 period. Isolations were made from the wood in the outer part of dead branches and from discoloured wood in the trunk that originated from a dead branch. Pure cultures were divided into morphotypes, and one representative culture per morphotype was selected for further molecular identification. From a total of 2700 cultured subsamples, 1744 fungal cultures were obtained, which were grouped into 212 morphotypes. The investigated samples were colonized by a broad spectrum of fungi. The most frequently isolated species were Eutypa maura (Fr.) Sacc., Eutypa sp. Tul. and C. Tul., Fusarium avenaceum (Fr.) Sacc., Neocucurbitaria acerina Wanas., Camporesi, E.B.G. Jones and K.D. Hyde and E. parasitica. In this study, we distinguished species diversity and the fungal community. There were no significant differences in the diversity of fungal species between the five sampling sites, and branch thickness did not prove to be a statistically significant factor in fungal species diversity. Nevertheless, relatively low Jaccard similarity index values suggested possible differences in the fungal communities from different sampling sites. This was confirmed by an analysis of similarities, which showed that the isolated fungal community distinctly differed between the five sampling sites and between the different isolation sources. Eutypella parasitica was isolated from all five investigated sampling sites, although Eutypella cankers were observed in only three sampling sites, indicating the possibility of asymptomatic infection. Full article

Three new pimarane diterpenes, eutypellenoids A–C (1–3), together with a known compound, eutypenoid C (4), were isolated from the culture extract of Eutypella sp. D-1 derived from the Arctic region. Compounds 1–3 possessed an uncommon tetrahydrofuran-fused pimarane diterpene skeleton. The structures of all compounds were determined by detailed spectroscopic analysis, electronic circular dichroism (ECD) analysis, as well as a comparison with the literature data. Antibacterial, antifungal, and cytotoxic activities of these compounds were evaluated. Compound 2 displayed antibacterial activity against Staphylococcus aureus and Escherichia coli with MIC values of 8 and 8 μg/mL, respectively. Additionally, compound 2 showed antifungal activity against Candida parapsilosis, Candida albicans, Candida glabrata, and Candida tropicalis with MIC values of 8, 8, 16, and 32 μg/mL, respectively. Furthermore, compound 2 exhibited moderate cytotoxic activity against HCT-116 cell line with IC₅₀ value of 3.7 μM. Full article

Eutypenoids A–C (1–3), pimarane diterpenoid alkaloid and two ring A rearranged pimarane diterpenoids, were isolated from the culture of Eutypella sp. D-1 obtained from high-latitude soil of the Arctic. Their structures, including absolute configurations, were authenticated on the basis of the mass spectroscopy (MS), nuclear magnetic resonance (NMR), X-ray crystallography, and electronic circular dichroism (ECD) analysis. The immunosuppressive effects of eutypenoids A–C (1–3) were studied using a ConA-induced splenocyte proliferation model, which suggested that 2 exhibited potent immunosuppressive activities. Full article