Structurally diverse diketopiperazine alkaloids from the marine-derived fungus Aspergillus versicolor SCSIO 41016

Abstract

Four novel 1-oxa-8,10-diazaspiro[5.5]undecane containing diketopiperazine alkaloids from Aspergillus versicolor SCSIO 41016.

HPLC-DAD-Guided Isolation of Diversified Chaetoglobosins from the Coral-Associated Fungus Chaetomium globosum C2F17

“…Cytochalasans have continuously aroused considerable interest from chemists and pharmacologists owing to their structural complexity and pharmacological significance. Sixteen structurally diverse chaetoglobosins, 10-(indol-3-yl)- [13]cytochalasans, including a new one, 6-O-methyl-chaetoglobosin Q (1), were encountered in the coral-associated fungus C. globosum C2F17. The X-ray crystal structures and absolute configurations of the previously reported chaetoglobosin E (6), penochalasin G (12), and armochaetoglobin G (13), are described here for the first time.…”

“…Taken together, the complete structure of 1 was established and accordingly assigned as 6-O-methyl-chaetoglobosin Q, which was probably obtained as an artifact from acidic solvolisis of the epoxide of chaetoglobosin A (2). Additionally, the structures of these known compounds (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16) were mainly elucidated by spectral data analysis as well as comparison with those reported in the literature. They were identified as chaetoglobosins A-G (2-8) [16][17][18], aureochaeglobosin B (9) [6], isochaetoglobosin D (10) [18], chaetoglobosin Fex (11) [16], penochalasin G (12) [19], armochaetoglobin G (13) [7], prochaetoglobosin I (14) [8], chaetoglobosins V b (15) [8] and Y (16) [18], respectively ( Figure 1).…”

“…Recently, a variety of cycloaddition heterodimers of cytochalasans with novel complicated architectures have been reported, exemplified by asperflavipine A [5], aureochaeglobosins A−C [6]. Chaetoglobosins, 10-(indol-3-yl)- [13]cytochalasans were recently reported to have cytotoxicity [6,7] and antibacterial activity [8], and have attracted great interest from both chemists and pharmacologists [9][10][11][12].…”

“…As part of our program to discover structurally novel and biologically significant secondary metabolites from marine fungi [13,14], our attention was drawn to the fungus Chaetomium globosum C2F17 derived from the coral Pocillopora damicornis, collected in the South China Sea. The HPLC with a diode-array detector (HPLC-DAD) analysis ( Figure S12) of its EtOAc extract based on solid rice fermentation combined with our in-house UV spectra library displayed the characteristic UV absorption bands at around 205, 220, and 275 nm, revealing the presence of a series of indole alkaloids.…”

A new p-terphenyl derivative from the insect-derived fungus Aspergillus candidus Bdf-2 and the synergistic effects of terphenyllin

“…In our previous study, five fungal isolates were isolated from the Blaptica dubia, and Aspergillus candidus Bdf-2 displayed the best antibacterial and antioxidant activities (Shan et al, 2019). Fungi belonging to the genus Aspergillus (Trichocomaceae) are one of the most prolific resources for compounds such as alkaloids (Si et al, 2018;Luo et al, 2019), steroids (Xing et al, 2019), anthraquinones (Xing et al, 2019;Li et al, 2019a), isocoumarins (Ma et al, 2019), polyketides (Qiao et al, 2018;Yin et al, 2018), terpenes (Li et al, 2019b), cyclopeptides (Liu et al, 2018), and p-terphenyls (Wang et al, 2017;Zhang et al, 2018). Metabolites isolated from species of the genus Aspergillus have continually attracted the interest of pharmacologists due to their broad array of biological activities and their structural diversity (Wang et al, 2017).…”