Antifungal and Antimicroalgal Trichothecene Sesquiterpenes from the Marine Algicolous Fungus Trichoderma brevicompactum A-DL-9-2

Abstract

Eight new trichothecene derivatives, trichodermarins G-N (1−8), and two new cuparene derivatives, trichocuparins A (9) and B (10), as well as six known trichothecenes (11−16) were isolated from the fungal strain Trichoderma brevicompactum A-DL-9-2 obtained from the inner tissue of the marine red alga Chondria tenuissima. The structures and relative configurations of 1−10 were assigned by NMR and MS data, and the absolute configurations of 1, 2, and 9 were established by X-ray diffraction. Compound 8 features an aminosugar unit bond to the trichothecene framework for the first time, while 9 and 10 represent the first occurrence of cuparene sesquiterpenes in Trichoderma. All the isolates were assayed for growth inhibition of five phytopathogenic fungi (Botrytis cinerea, Cochliobolus miyabeanus, Fusarium oxysporum f. sp. cucumerium, Fusarium oxysporum f. sp. niveum, and Phomopsis asparagi) and four marine phytoplankton species (Amphidinium carterae, Heterocapsa circularisquama, Heterosigma akashiwo, and Prorocentrum donghaiense). Several of them exhibited significant inhibitory activities against the fungi and phytoplankton tested of which trichodermin (12) showed the highest antifungal and antimicroalgal activities with MIC and IC 50 values being 4.0 and 0.82 μg/mL, respectively.

New Trichothecenes Isolated from the Marine Algicolous Fungus Trichoderma brevicompactum

“…A number of new compounds from marine fungi have been discovered from various sources, including extreme sea environment. These compounds showed various activities including anticancer, antimicroalgal, antibacterial, and antiviral effects [3][4][5]. The vast symbiotic relationships and diversity of many marine organisms has caused marine fungi to distribute in almost all marine habitats, including from marine ray-finned fish, sponges, mangroves, and algae [3,[5][6][7].…”

“…The vast symbiotic relationships and diversity of many marine organisms has caused marine fungi to distribute in almost all marine habitats, including from marine ray-finned fish, sponges, mangroves, and algae [3,[5][6][7]. Among them, marine algae-derived fungi offer opportunities and attract attention because they produce secondary metabolites with unique chemical diversity and various pharmacological properties [4,6,[8][9][10][11].…”

“…Trichoderma species are commonly present in all soils and various habitats, including marine habitats and marine sediments [4,8,12,13]. The genus Trichoderma produces metabolites with trichothecene scaffold and other skeletal metabolites including epipolythiodioxopiperazines, peptides, pyrones, butenolides, pyridones, anthraquinones, and steroids, along with various low molecular weight compounds [14].…”

“…The genus Trichoderma produces metabolites with trichothecene scaffold and other skeletal metabolites including epipolythiodioxopiperazines, peptides, pyrones, butenolides, pyridones, anthraquinones, and steroids, along with various low molecular weight compounds [14]. Trichothecenes are a family of sesquiterpenes with a tetracyclic 12,13-epoxytrichothec-9-ene ring that have been identified in several fungal genera including Trichoderma, Myrothecium, Trichothecium, and Fusarium [4,7,15,16]. Trichothecene derivatives including trichodermin, HT-2 toxin, deoxynivalenol, and satratoxin were reported to exhibit activities such as cytotoxic, antiphytopathogenic, antimicroalgal, antifungal, antimalarial, antiviral, antibiotic, and antileukemic effects [4,12,[15][16][17][18][19].…”

“…Trichothecenes are a family of sesquiterpenes with a tetracyclic 12,13-epoxytrichothec-9-ene ring that have been identified in several fungal genera including Trichoderma, Myrothecium, Trichothecium, and Fusarium [4,7,15,16]. Trichothecene derivatives including trichodermin, HT-2 toxin, deoxynivalenol, and satratoxin were reported to exhibit activities such as cytotoxic, antiphytopathogenic, antimicroalgal, antifungal, antimalarial, antiviral, antibiotic, and antileukemic effects [4,12,[15][16][17][18][19]. In this study, a chemical investigation was performed on solid fermented products of T. brevicompactum NTU439, which has resulted in the isolation and identification of four new trichothecenes 1-4, together with five known compounds.…”