Eremophilane-Type Sesquiterpenoids from an Acremonium sp. Fungus Isolated from Deep-Sea Sediments

Abstract

Chemical examination of an EtOAc extract of a cultured Acremonium sp. fungus from deep-sea sediments resulted in the isolation of 15 new eremophilane-type sesquiterpenoids, namely, acremeremophilanes A-O (1-15), together with seven known analogues. The structures of new compounds were determined through extensive spectroscopic analyses, in association with chemical conversions and ECD calculations for configurational assignments. The PKS-derived 4-hexenoic acid unit in 2-6 is rarely found in nature. All compounds were evaluated for inhibitory effects toward nitric oxide production induced by lipopolysaccharide in RAW 264.7 macrophage cells. Compounds 2-6 and 14 exhibited inhibitory effects with IC50 values ranging from 8 to 45 μM.

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

“…The other isolated compounds were identified by comparing the spectroscopic data with the literature and included guignarderemophilane D (15) (Liu et al, 2015), 1α-hydroxyhydroisofukinon (16) (Bohlmann and Knoll, 1979), 2β-hydroxyl-1,7(11),9-eremorphilatrien-8-one (17) (Lin et al, 2014), guignarderemophilane B (18) (Liu et al, 2015), PR-toxin dimethyl acetal (19) (Darsih et al, 2015), 2-oxo-3-hydroxy-eremophila-1(10),3,7(11),8-tetraen-8,12-olide (20) (Qin et al, 2015), acremeremophilane N (21) (Cheng et al, 2016), and 2α-methoxyl-3β-acetoxyleremophila-1(10),7(11),8-trien-8,12-olactam (22) (Lin et al, 2014).…”

Natural Products Research in China From 2015 to 2016

“…(South Atlantic Ocean), among which acremeremophilanes B–F ( 22 - 26 ) contained a novel 4-hexenoic acid unit. Acremeremophilane B ( 22 ) showed the inhibition on the LPS-induced NO production in RAW 264.7 macrophage cell lines with an IC 50 value of 8 μM (reference quercetin, 15 μM) (Cheng et al, 2016 ). The fungus Aspergillus ochraceopetaliformis SCSIO 05702 (sediment, Chinese Antarctic station) produced five highly oxygenated α-pyrone merosesquiterpenoids, ochraceopones A–E, along with a new isomer of asteltoxin, isoasteltoxin ( 27 ).…”

Butenolide Derivatives with α-Glucosidase Inhibitions from the Deep-Sea-Derived Fungus Aspergillus terreus YPGA10

“…In recent years, deep-sea fungi have been well recognized as a rich source of secondary metabolites endowed with unusual structures and significant bioactivities [12]. As part of our ongoing efforts to discover bioactive molecules from deep-sea derived fungi [13,14,15,16,17], an EtOAc extract of a fungal strain Aspergillus terreus YPGA10 displayed the 1 H NMR resonances similar to those of butyrolactone I. A bioassay revealed that the EtOAc extract possessed an inhibition rate of 67% at a single dose (100 μg/mL) against α -glucosidase.…”