Eremophilane-Type Sesquiterpenoids From the Endophytic Fungus Rhizopycnis vagum and Their Antibacterial, Cytotoxic, and Phytotoxic Activities

Abstract

Fourteen new eremophilane-type sesquiterpenoids, named rhizoperemophilanes A∼N (1∼14), together with eight known congeners, were isolated from the culture of the endophytic fungus Rhizopycnis vagum. The structures of the new compounds were elucidated by extensive spectroscopic analyses, as well as ECD calculations and the modified Mosher's method for the assignment of the absolute configurations. Rhizoperemophilane J (10) contains an uncommon C-4/C-11 epoxy ring, while rhizoperemophilane N (14) features an unprecedented 3-nor-eremophilane lactone-lactam skeleton. These metabolites were evaluated for their antibacterial, cytotoxic, and phytotoxic activities. Among them, compounds 11, 16, and 20 displayed antibacterial activities, while 14 showed selective cytotoxicity against NCI-H1650 and BGC823 tumor cells. Moreover, compounds 5, 6, 12, 13, 16, and 19 exhibited strong phytotoxic activities against the radicle elongation of rice seedlings.

Phytotoxic Secondary Metabolites from Fungi

“…Rhizoperemophilane M (383) was a nitrogen-containing eremophilane-type sesquiterpenoids isolated from the endophytic fungus Rhizopycnis vagum. This metabolite inhibited radicle elongation of rice seedlings [212].…”

“…Moreover, 1α-hydroxyhydroisofukinon ( 289 ), PR-toxin dimethyl acetal ( 312 ), and rhizoperemophilanes E ( 316 ), F ( 317 ), and L ( 318 ) were nitrogen-containing eremophilane-type sesquiterpenoids isolated from the endophytic fungus Rhizopycnis vagum . These metabolites inhibited radicle elongation of rice seedlings [ 212 ].…”

Eremophilane Sesquiterpenoids with Antibacterial and Anti-inflammatory Activities from the Endophytic Fungus Septoria rudbeckiae

“…Eremophilane sesquiterpenes, consisting of three isoprenes, possess the identical decalin framework with the eudesmanes and probably belong to a small group of sesquiterpenes. , Eremophilane sesquiterpenoids widely existed in numerous medicinal plants, especially in the Asteraceae family. − Subsequently, the metabolites of eremophilanes produced by theendophytic and marine fungi have increased remarkably, with some exhibiting multiple bioactivities including antifungal, anti-inflammatory, antivirus, antibacterial, and insecticidal activities. − Owing to the structural diversiform and unique biological activities of eremophilane sesquiterpenes, extensive phytochemical and biological investigations have been carried out by numerous scientists. − Consequently, further studies toward the development of novel and medicinally valuable sesquiterpenoids are essential.…”

Biotransformation ability of endophytic fungi: from species evolution to industrial applications

“…CGMCC 5416 Chermesinone B Anti-HIV-1 virus, cytotoxic activity Yang et al ( 2020b ) 42 Phomopsone C 43 Cyclosorus parasiticus Diaporthe sp. SC-J0138 Diaporthichalasin D Cytotoxic activity Yang et al ( 2020a ) 44 Diaporthichalasin H 45 Nicotiana tabacum Rhizopycnis vagum KM095527 Rhizoperemophilane J Wang et al ( 2020 ) 46 Rhizoperemophilane N 47 Salvia miltiorrhiza Streptomyces sp. PKU-EA00015 Strepimidazoles A Antifungal activity Sun et al ( 2020 ) 48 Strepimidazoles B 49 Strepimidazoles C 50 Strepimidazoles D 51 Strepimidazoles E 52 Strepimidazoles F 53 Strepimidazoles G 54 Elaeis guineensis Jacq Streptomyces palmae CMU-AB204 ( Z )-5-(o-tolyl)pent-4-enoic acid Antifungal activity Sujarit et al ( 2020 ) 55 ( Z )-7-(o-tolyl)hept-6-enoic acid 56 ...…”