Characterization of Cytochalasins from the Endophytic Xylaria sp. and Their Biological Functions

Abstract

Bioassay-guided fractionation of the fermentation extract of Xylaria sp. XC-16, an endophyte from Toona sinensis led to the isolation of two new cytochalasans cytochalasin Z27, 1, and cytochalasin Z28, 2, along with three known compounds seco-cytochalasin E, 3, and cytochalasin Z18, 4, and cytochalasin E, 5. The structures of 1 and 2 were elucidated by spectroscopic and electronic circular dichroism methods. Compound 5 was shown to be potently cytotoxic against brine shrimp (LC50 = 2.79 μM), comparable to that of the positive agent toosendanin (LC50 = 4.03 μM), and also exhibited potential phytotoxic effects on Lactuca sativa and Raphanus sativus L. seedlings, which are higher than that of the positive control glyphosate. Additionally, the fungicidal effect of 2 against the phytopathogen Gibberella saubinetti was better than that of hymexazol. This is the first report of the three types of cytochalasins present in genus Xylaria. A structure-phytotoxicity activity relationship is also discussed.

Characterization of Diterpenes from Euphorbia prolifera and Their Antifungal Activities against Phytopathogenic Fungi

“…3−6 Therefore, there is an urgent need to develop new 35 antifungal agents to control those crop diseases effectively. One strategy to develop new antifungal 36 agents is to search for biologically active substances or lead compounds from plant secondary 37 metabolites, which has been proven to be effective and practicable for new pesticides of agricultural 38 field 7 and new drugs of medical field. 8 39 Euphorbia prolifera Buch-Ham., belonging to the Euphorbiaceae family, is a perennial herbaceous 40 plant distributed mainly in southwest China.…”

New cytochalasin fromRosellinia sanctae-cruciana, an endophytic fungus ofAlbizia lebbeck

“…The 13 C NMR spectra of 1 (Table ) showed similar chemical shifts to that of cytochalasin D, especially of the macrocyclic ring moiety (Zhang et al . ). Further, it was concluded that 1 has the same configuration of cytochalasin D, and its structure is determined as 7‐keto,19,20‐epoxycytochalasin and named jammosporin A ( 1 ).…”

“…These include the stereochemistry of the macrocyclic ring, with a trans C-8/C-9 junction and a cis C-4/C-9 junction and the a-orientation of Me-22 and the E configuration of the C-13/C-14 double bond. The 13 C NMR spectra of 1 (Table 2) showed similar chemical shifts to that of cytochalasin D, especially of the macrocyclic ring moiety (Zhang et al 2014). Further, it was concluded that 1 has the same configuration of cytochalasin D, and its structure is determined as 7-keto,19,20-epoxycytochalasin and named jammosporin A (1).…”

Antimicrobial activities of an oxygenated cyclohexanone derivative isolated from Amphirosellinia nigrospora JS-1675 against various plant pathogenic bacteria and fungi

“…), cytochalasins (Zhang et al . ) and xylaranol B (Chen et al . ) are produced by members of the genus Xylaria , the largest and the most diverse genus in the Xylariaceae.…”