Secondary Metabolites and Their Biological Activity from Aspergillus aculeatus KKU-CT2

Abstract

The bioactive compounds of the fungus Aspergillus aculeatus strain KKU-CT2, have been studied. The crude extracts from this fungus showed good antimicrobial activity against human pathogens, including Gram-positive and Gram-negative bacteria and yeast-like fungi. Its chemical components were isolated and purified by chromatographic methods. The structures of the secondary metabolites were elucidated by spectroscopic methods (IR, H, andC NMR). They were identified as ergosterol peroxide (1), secalonic acid D (2), secalonic acid F (3), variecolin (4), variecolactone (5), and ergosterol (6). Compounds 1 and 4-6 are reported for the first time as fungal metabolites from this species. Compound 1 displayed inhibitory effects on HSV-1 with an IC of 11.01 μg/ml. Compounds 3, 4, and 6 exhibited antimalarial activity against Plasmodium falciparum with IC of 1.03, 1.47, and 5.31 µg/ml, respectively. Additionally, all compounds from A. aculeatus KKU-CT2 showed unprecedented anticancer activities against human epidermoid carcinoma in the mouth (KB) (compounds 1-6), human breast cancer (MCF-7) (compounds 2, 4, and 5), and human lung cancer cells (NCI-H187) (compounds 1-4 and 6). These results suggest that secondary metabolites from A. aculeatus KKU-CT2 might be interesting for further derivatization, targeting diseases such as cancer.

Discovery of a Secalonic Acid Derivative fromAspergillus aculeatus, an Endophyte ofRosa damascenaMill., Triggers Apoptosis in MDA-MB-231 Triple Negative Breast Cancer Cells

“…So far, there are several reports documenting the bioactive potential of its compounds including secalonic acids A, D, and F which have shown incredible anticancer activities. 13 The secalonic acid family (SAF), natural mycotoxins, including dimers of six different monoxanthones (secalonic acids A–F) with a dimeric tetrahydroxanthenone skeleton exhibits a wide range of anticancer activities including inhibition of DNA topoisomerase I and protein kinase C. 14 Previous studies have highlighted that SAF inhibits the proliferation and promotes the apoptosis of HepG2 cells, repressing the progression of hepatocellular carcinoma via MARCH1 regulation of the PI3K/AKT/β-catenin signaling pathway and also the SAF inhibits VEGF-mediated angiogenesis through the Akt/mTOR pathway in breast cancer. 14 , 15 In the present study, we report a novel derivative of secalonic acid from A. aculeatus MBT-102, an endophyte of Rosa damascena , and its cytotoxic potential against TNBC cells.…”

Structure revision of cryptosporioptides and determination of the genetic basis for dimeric xanthone biosynthesis in fungi

“…We then used the cryptosporioptide BGC to screen the genomes of other fungi for similar clusters. Penicillium oxalicum 29 and Aspergillus aculeatus 30 are both known to produce secalonic acid D 11 ,31 and their genomes have been sequenced 32. In both cases we found a BGC ( P. oxa , A. acu Table 1) featuring homologs of many of the genes in the dmx BGC.…”

Occurrence of filamentous fungi isolated from matured blue cheese

“…Aflatoxin M1 is the only mycotoxin controlled by the Brazilian Health Regulatory Agency (ANVISA) in cheese, a maximum tolerable limit is 2.5 µg/kg (Brasil, 2011), Aspergilli species reported in this work belong mainly to Nigri section, known as black aspergilli, A. aculeatus is also a member of Nigri section and was by far the most prevalent species characterized in all analyzed samples (Figure 3). This group is responsible for producing a variety of bioactive natural products, including aculeacins (antibiotics and antifungal agents), CJ-15,183 (antifungal agent) and secalonic acids (toxins) (Yodsing et al, 2018). Although no clear risk of A. aculeatus presence in cheese has been assessed yet, this species wields an array of molecular weapons against other microorganisms, and could impair proper P. roqueforti development affecting the final quality of blue veined cheese.…”