Cytotoxic and antibacterial depsidones from the endophytic fungus Chaetomium brasiliense isolated from Thai rice

Abstract

Four new depsidones, mollicellins V-Y (1-4), together with eight known depsidones (5-12) were isolated from the endophytic fungus, Chaetomium brasiliense, detached from stems of Thai rice.Their structures were determined by extensive spectroscopic methods. Mollicellins X, H, and F (3, 8 and 10) showed potent cytotoxicity against the human oral epidermoid carcinoma (KB) cell line, and mollicellin F (10) also showed a potent cytotoxicity against the human hepatocellular carcinoma (HepG2) cell line. Besides, mollicellin B (11) exhibited cytotoxicity against the colorectal adenocarcinoma (HT-29) cell line. Moreover, most of the isolated depsidones displayed potent antibacterial activity against Gram-positive bacteria, Bacillus cereus and Bacillus subtilis, and several of them showed moderate activity against Methicillin-resistant Staphylococcus aureus (MRSA) and clinical isolates of S. aureus. In addition, a few of them also showed moderate activity against a Gram-negative bacteria Pseudomonas aeruginosa.

Recent advances on natural depsidones: sources, biosynthesis, structure-activity relationship, and bioactivities

“…Compounds 92 – 95 , 108 , and 109 had powerful antibacterial potential against Bacillus subtilis and Bacillus cereus (MICs 2.0–8.0 μg/mL) which was close to kanamycin (MICs 2.0 μg/mL), however, they displayed moderate efficacy on S. aureus ATCC25923 (MICs 16.0–64.0 μg/mL). Besides, 91 , 92 , 97 , 110 , and 111 were moderately active against different MRSA isolates (ATCC33591, ATCC33592, and ATCC43300, MICs 32.0–128.0 μg/mL) with the same MICs as oxacillin (MICs 32.0–128.0 μg/mL), whereas 91 and 92 also had moderate influence (MICs 32.0–128.0 μg/mL) against S. aureus SA1-3 clinical isolates ( Promgool et al, 2022 ). It was noted that C-4-CHO and complete lactone ring were significant for antibacterial potential against Gram-positive bacteria ( Promgool et al, 2022 ).…”

“…Besides, 91 , 92 , 97 , 110 , and 111 were moderately active against different MRSA isolates (ATCC33591, ATCC33592, and ATCC43300, MICs 32.0–128.0 μg/mL) with the same MICs as oxacillin (MICs 32.0–128.0 μg/mL), whereas 91 and 92 also had moderate influence (MICs 32.0–128.0 μg/mL) against S. aureus SA1-3 clinical isolates ( Promgool et al, 2022 ). It was noted that C-4-CHO and complete lactone ring were significant for antibacterial potential against Gram-positive bacteria ( Promgool et al, 2022 ).…”

“…New members of mollicellin family; mollicellins 108 – 111 , together with 92 , 94 , 95 , 97 , 99 , 100 , and 104 were separated utilizing SiO 2 CC/preparative TLC from Thai rice-accompanied C . Brasiliense ( Promgool et al, 2022 ). Compounds 92 – 95 , 108 , and 109 had powerful antibacterial potential against Bacillus subtilis and Bacillus cereus (MICs 2.0–8.0 μg/mL) which was close to kanamycin (MICs 2.0 μg/mL), however, they displayed moderate efficacy on S. aureus ATCC25923 (MICs 16.0–64.0 μg/mL).…”

“…A study by Promgool et al (2022) showed that mollicellins 91 , 92 , 94 , 95 , 97 , 99 , 100 , 104 , and 108 - 110 exhibited cytotoxic efficacy against Hela, KB, HepG2, MCF-7, and HT-29 cell lines (IC 50 s 4.79–92.11 μM), where 95 , 97 , and 110 (IC 50 s 4.79, 10.64, and 9.83 μM, respectively) and 91 , 95 , and 110 (IC 50 s 10.66, 7.10, and 11.69 μM, respectively) were potent against KB and HepG2 cell lines, respectively. These metabolites were cytotoxic on Vero cells (IC 50 s 5.65–54.06 μM) except 111 .…”

Genome Mining and Biosynthetic Reconstitution of Fungal Depsidone Mollicellins Reveal a Dual Functional Cytochrome P450 for Ether Formation

“…Mollicellins are a representative type of depsidones with an isopentenyl modification which are produced by the Chaetomiaceae family, and 25 mollicellins (mollicellins A–Y) have been discovered. ,− However, biosynthetic studies of mollicellins have rarely been reported. In this work, we report the production of the new mollicellins Z ( 9 ) and Z1 ( 10 ) in Aspergillus nidulans A1145 by heterologous expression of a depsidone-encoding BGC from Ovatospora sp.…”