Cytochalasins from endophytic Diaporthe sp. GDG-118

Abstract

The plant Sophora tonkinensis, possessed a range of active compounds, was traditionally used in the medicine of Chinese minorities. Endophytic fungi were isolated from this plant, of which the fungus Diaporthe sp. GDG-118 was fermented and extracted with methanol. The extract was screened by antifungal and antibacterial assays leading to the discovery of two new 21-acetoxycytochalasins (1-2) and five known cytochalasins (3-7). These two new compounds were elucidated by spectroscopic analyses, and further their absolute configurations were determined by the X-ray of compound 3 and comparing their experimental CD spectra. The antibacterial and antifungal effects of these compounds were evaluated. Compound 2 showed moderate inhibitory activity against Bacillus anthraci and Escherichia coli with MIC value of 12.5 μg/mL, and 7 showed strong antifungal activity against Alternaria oleracea, Pestalotiopsis theae and Colletotrichum capsici with MIC values of 3.125 μg/mL, 1.56 μg/mL and 1.56 μg/mL, respectively.

Fungal Endophytes: A Potential Source of Antibacterial Compounds

“…An endophytic fungus, Diaporthe sp. GDG-118, associated with Sophora tonkinensis collected from Hechi City (China) yielded a new compound 21-acetoxycytochalasin J3 (3, Figure 1) and inhibited the pathogens Bacillus anthraci and E. coli at 12.5 µg/mL concentration (6 mm sterile filter paper discs were impregnated with 20 µL (50 µg) of each compound) [19].…”

Bioactive Secondary Metabolites of the Genus Diaporthe and Anamorph Phomopsis from Terrestrial and Marine Habitats and Endophytes: 2010–2019

“…megaterium and Bacillus anthraci ) and Gram-negative bacteria ( Proteus vuigaris , E . coli and Salmonella paratyphi B ) with MIC values in the range of 12.5–100 μg/mL [ 158 ]. The fungus Diaporthe sp.…”

Cytochalasans from the Endophytic Fungus Phomopsis sp. shj2 and Their Antimigratory Activities

“…Compounds 8 – 11 were identified as cytochalasin H ( 8 ) [ 23 ], cytochalasin J 1 ( 9 ) [ 24 ], RKS-1778 ( 10 ) [ 25 ], 21-acetoxycytochalasin J 2 ( 11 ) [ 26 ] on the basis of their spectroscopic features and by comparison with the published data in the literature. Biogenetically, compounds 1 – 11 might be derived from a polyketide chain (octaketide) and an amino acid building block (phenylalanine) through a number of steps involving cycloaddition, oxidation, reduction, dehydration, acetylation, ethylation and methylation [ 27 , 28 ].…”