New Polyketides from the Antarctic Fungus Pseudogymnoascus sp. HSX2#-11.

The species Pseudogymnoascus is known as a psychrophilic pathogenic fungus with a ubiquitous distribution in Antarctica. Meanwhile, the study of its secondary metabolites is infrequent. Systematic research of the metabolites of the fungus Pseudogymnoascus sp. HSX2#-11, guided by the method of molecular networking, led to the isolation of one novel polyketide, pseudophenone A (1), along with six known analogs (2-7). The structure of the new compound was elucidated by extensive spectroscopic investigation and single-crystal X-ray diffraction. Pseudophenone A (1) is a dimer of diphenyl ketone and diphenyl ether, and there is only one analog of 1 to the best of our knowledge. Compounds 1 and 2 exhibited antibacterial activities against a panel of strains. This is the first time to use molecular networking to study the metabolic profiles of Antarctica fungi.

Nitrogenous Compounds from the Antarctic Fungus Pseudogymnoascus sp. HSX2#-11.

The species Pseudogymnoascus is known as a psychrophilic pathogenic fungus which is ubiquitously distributed in Antarctica. While the studies of its secondary metabolites are infrequent. Systematic research of the metabolites of the Antarctic fungus Pseudogymnoascus sp. HSX2#-11 led to the isolation of one new pyridine derivative, 4-(2-methoxycarbonyl-ethyl)-pyridine-2-carboxylic acid methyl ester (1), together with one pyrimidine, thymine (2), and eight diketopiperazines, cyclo-(dehydroAla-l-Val) (3), cyclo-(dehydroAla-l-Ile) (4), cyclo-(dehydroAla-l-Leu) (5), cyclo-(dehydroAla-l-Phe) (6), cyclo-(l-Val-l-Phe) (7), cyclo-(l-Leu-l-Phe) (8), cyclo-(l-Trp-l-Ile) (9) and cyclo-(l-Trp-l-Phe) (10). The structures of these compounds were established by extensive spectroscopic investigation, as well as by detailed comparison with literature data. This is the first report to discover pyridine, pyrimidine and diketopiperazines from the genus of Pseudogymnoascus.

Self-developed NF-κB inhibitor 270 protects against LPS-induced acute kidney injury and lung injury through improving inflammation.

Sepsis-induced acute kidney injury (AKI) and acute lung injury (ALI) have high morbidity and mortality, with no effective clinically available drugs. Anti-inflammation is effective strategy in the therapy of AKI and ALI. NF-κB is a target for the development of anti­inflammatory agents. The purpose of the study is to evaluate the effect of 270, self-developed NF-κB inhibitor, in LPS-induced AKI and ALI. LPS-induced macrophages were used to examine the anti-inflammation activity of 270 in vitro. Sepsis-induced AKI and ALI mice models were established by intraperitoneal injection of LPS (10 mg/kg) for 24 h. Oral administration 270 for 14 days before LPS stimulation. Plasma, kidney and lung tissues were collected and used for histopathology, biochemical assay, ELISA, RT-PCR, and western blot analyses. In vitro, we showed that 270 suppressed the inflammation response in LPS-induced RAW 264.7 macrophages and bone marrow derived macrophages. In vivo, we found that 270 ameliorated LPS-induced AKI and ALI, as evidenced by improving various pathological changes, reducing the expression of pro-inflammation genes, blocking the activation of NF-κB and JNK pathways, attenuating the elevated myeloperoxidase (MPO) activity and malondialdehyde (MDA) content, ameliorating the activated ER stress, reversing the inhibition effect on autophagy in kidney and lung tissues, and alleviating the enhanced plasma level of creatinine (Crea), blood urea nitrogen (BUN) and pro-inflammation cytokines. Our investigations provides evidence that NF-κB inhibitor 270 is a potential drug that against LPS-induced AKI and ALI in the future.

Sesquiterpenoids From the Antarctic Fungus Pseudogymnoascus sp. HSX2#-11.

The fungal strains Pseudogymnoascus are a kind of psychrophilic pathogenic fungi that are ubiquitously distributed in Antarctica, while the studies of their secondary metabolites are infrequent. Systematic research of the metabolites of the fungus Pseudogymnoascus sp. HSX2#-11 led to the isolation of six new tremulane sesquiterpenoids pseudotremulanes A-F (1-6), combined with one known analog 11,12-epoxy-12ß-hydroxy-1-tremulen-5-one (7), and five known steroids (8-12). The absolute configurations of the new compounds (1-6) were elucidated by their ECD spectra and ECD calculations. Compounds 1-7 were proved to be isomeride structures with the same chemical formula. Compounds 1/2, 3/4, 1/4, and 2/3 were identified as four pairs of epimerides at the locations of C-3, C-3, C-9, and C-9, respectively. Compounds 8 and 9 exhibited cytotoxic activities against human breast cancer (MDA-MB-231), colorectal cancer (HCT116), and hepatoma (HepG2) cell lines. Compounds 9 and 10 also showed antibacterial activities against marine fouling bacteria Aeromonas salmonicida. This is the first time to find terpenoids and steroids in the fungal genus Pseudogymnoascus.