Perylenequione Derivatives with Anticancer Activities Isolated from the Marine Sponge-Derived Fungus, Alternaria sp. SCSIO41014

Abstract

Seven new secondary metabolites classified as two perylenequinone derivatives (1 and 2), an altenusin derivative (3), two phthalide racemates (4 and 5), and two phenol derivatives (6 and 7), along with twenty-one known compounds (8–28) were isolated from cultures of the sponge-derived fungus, Alternaria sp. SCSIO41014. The structures and absolute configurations of these new compounds (1–7) were determined by spectroscopic analysis, X-ray single crystal diffraction, chiral-phase HPLC separation, and comparison of ECD spectra to calculations. Altertoxin VII (1) is the first example possessing a novel 4,8-dihydroxy-substituted perylenequinone derivative, while the phenolic hydroxy groups have commonly always substituted at C-4 and C-9. Compound 1 exhibited cytotoxic activities against human erythroleukemia (K562), human gastric carcinoma cells (SGC-7901), and hepatocellular carcinoma cells (BEL-7402) with IC50 values of 26.58 ± 0.80, 8.75 ± 0.13, and 13.11 ± 0.95 μg/mL, respectively. Compound 11 showed selectively cytotoxic activity against K562, with an IC50 value of 19.67 ± 0.19 μg/mL. Compound 25 displayed moderate inhibitory activity against Staphylococcus aureus with an MIC value of 31.25 μg/mL.

Altertoxins with Quorum Sensing Inhibitory Activities from The Marine-Derived Fungus Cladosporium sp. KFD33

“…The observed HMBC correlations from H-7 to C-5 and from H-6 to C-8 suggested that there is a C-8/C-5 linkage. The above data revealed that compound 1 was structurally similar to altertoxin VII [11], except for the absence of a hydroxyl group located at C-7 . The ECD curve of 1 showed negative Cotton effects (CEs) around 225 and 260 nm and positive one around 280 nm, which is very similar to that of altertoxin VII [11], suggesting their same absolute configuration, i.e., 1 R.…”

Altertoxins with Quorum Sensing Inhibitory Activities from the Marine-Derived Fungus <em>Cladosporium</em> sp. KFD33

“…The observed HMBC correlations from H-7 to C-5' and from H-6' to C-8 suggested that there is a C-8/C-5' linkage. The above data revealed that compound 1 was structurally similar to altertoxin VII [9], except for the absence of a hydroxyl group located at C-7' (δC 126.2). The ECD curve of 1 showed negative Cotton effects (CEs) around 225 and 260 nm and positive one around 280 nm, which is very similar to that of altertoxin VII [9], suggesting their same absolute configuration, i.e.…”

Mining the Metabolome and the Agricultural and Pharmaceutical Potential of Sea Foam-Derived Fungi

“…Amidst the many compounds already reported in this class, some nodes in the cluster were not annotated, and may represent potentially novel compounds. Some other annotated parent ions include the phenolic compound alternariphent A1 [41], alkaloid stachybotrin A [39] and nortriterpenoid helvolic acid methyl ester [65] with reported antibacterial and antifungal activities (DNP). The minimal activities observed against the tested pathogens (Table S3) may be attributed to a low concentration of the bioactive compounds.…”

“…This resulted in the annotation of about 10% of the parent ions ( Figure 6). Some annotated ions included the indole alkaloid cytochalasin R [36], pyranone betulinan C [37], alkaloids, 3-acetyl-5-isopropyl-pyrrolidine-2,4-dione [38] and stachybotrin A [39], phenol derivative alternariphent A1 [40,41] and nortriterpenoid deacetyl helvolic acid [42]. Although two fungal isolates emerged in two different clades in the phylogenetic analysis ( Figure S1) belonging to the orders Capnodiales (Cladosporium sp.)…”