Zopfiellasins A–D, Two Pairs of Epimeric Cytochalasins from Kiwi-Associated Fungus Zopfiella sp. and Their Antibacterial Assessment

Abstract

In our continuous search for antibacterial agents against Pseudomonas syringae pv. actinidiae (Psa) from kiwi-associated fungi, two pairs of epimeric cytochalasins, zopfiellasins A–D (1–4), were characterized from the fungus Zopfiella sp. The structures were established on the basis of spectroscopic data analysis, while the absolute configurations were determined by single-crystal X-ray diffraction. Compounds 1 and 3 exhibited antibacterial activity against Psa with MIC values of 25 and 50 μg/mL, respectively. This is the first report of anti-Psa activity of cytochalasin derivatives.

Sesquiterpenoids and Xanthones from the Kiwifruit-Associated Fungus Bipolaris sp. and Their Anti-Pathogenic Microorganism Activity

“…Therefore, we carried out the excavation of anti-Psa active substances from metabolites of kiwifruit endophytes and harvested a number of bioactive molecules. For instance, 3-decalinoyltetramic acids and cytochalasins from the kiwifruit endophytic fungus Zopfiella sp showed anti-Psa activity [23,24], while imidazole alkaloids ether were characterized as anti-Psa agents from Fusarium tricinctum [25]. These discoveries prompted us to search for more novel and bioactive metabolites from kiwifruitassociated fungi.…”

Antibacterial Metabolites from Kiwi Endophytic Fungus Fusarium tricinctum, a Potential Biocontrol Strain for Kiwi Canker Disease

“…At the same time, Psa cultivated alone in PDA and in the L−B broth was used as a control group. 1,29 All the plates were deposited at 25 °C for 4 days. The growth-inhibition rate of the bacterium was calculated by the following formula: inhibition rate (IR) = (A 1 − A 2 )/A 1 × 100, where A 1 represents the area of the control group and A 2 represents that of the treatment group.…”

“…Our strategy has been to mine bioactive substances from the endophytes of the kiwi plant itself. Many anti-Psa products have been found in recent years using similar methods, such as the sesquiterpene bipolenin J and bipolarisorokin M from the fungus Bipolaris sp., , isobenzofuranones and isocoumarins from the fungus Paraphaeosphaeria sporulosa, and 3-decalinoyltetramic acid derivatives and sesquiterpenes from the fungus Zopfiella sp. − All these kiwi endophytic fungal products have shown remarkable anti-Psa activities. These findings encouraged us to search for more anti-Psa metabolites from kiwi endophytes.…”

Terpenoids from Kiwi endophytic fungus Bipolaris sp. and their antibacterial activity against Pseudomonas syringae pv. actinidiae

“…For example, 3-decalinoyltetramic acids and cytochalasins from the kiwifruit endophytic fungus Zopfiella sp. Showed anti-Psa activity ( Yi et al, 2021 ; Zhang et al, 2021 ), while imidazole alkaloids from Fusarium tricinctum were characterized as anti-Psa agents ( Ma et al, 2022 ). Bipolaris sp.…”