Aspeterreurone A, a Cytotoxic Dihydrobenzofuran-Phenyl Acrylate Hybrid from the Deep-Sea-Derived Fungus Aspergillus terreus CC-S06-18.

A new dihydrobenzofuran-phenyl acrylate hybrid, aspeterreurone A (1), was obtained from the culture of the deep-sea-derived fungus Aspergillus terreus CC-S06-18. The relative configuration of 1 was elucidated by HSQMBC NMR, calculated NMR chemical shifts coupled with a statistical procedure (DP4+), and the absolute configuration was established by ECD calculations. 1 exhibited cytotoxicities against the gastric cancer cell lines HGC27, MGC803, BGC823, and AGS, with minimal effects on normal gastric epithelial cell line GES-1. Further studies showed that 1 inhibited cell cycle progression and induced apoptosis of gastric cancer MGC803 cells in a concentration-dependent manner. Western blot analysis indicated that 1 inhibited the phosphorylation of STAT3, which might contribute to its cytotoxic activity.

Cytotoxic Nitrogenated Azaphilones from the Deep-Sea-Derived Fungus Chaetomium globosum MP4-S01-7.

Eight new nitrogenated azaphilones (1-8) and two known compounds (chaetoviridin A and chaetoviridin E, 9, 10) were isolated from the culture of the deep-sea-derived fungus Chaetomium globosum MP4-S01-7. The absolute configurations of new compounds were elucidated by HSQC-HECADE NMR data, J-based configuration analysis, and modified Mosher's method and finally verified by comparison of recorded and computed NMR chemical shifts from quantum chemical calculations coupled with a statistical procedure (DP4+). All of the compounds were evaluated for their in vitro cytotoxicities against the gastric cancer cell lines MGC803 and AGS, and most of them showed significant inhibition on cancer cell viability at 10 µM. Among them, compounds 1, 2, and 5 exerted the most potent cytotoxic activities, with IC50 values less than 1 µM. Further studies showed that compound 2 inhibited cell cycle progression, and both compounds 1 and 2 induced apoptosis of gastric cancer cells in a concentration-dependent manner.

[Extremely low frequency electromagnetic radiation enhanced energy metabolism and induced oxidative stress in Caenorhabditis elegans].

The aim of this study was to determine the effects of extremely low frequency electromagnetic field (ELF-EMF) on energy metabolism and oxidative stress in Caenorhabditis elegans (C. elegans). Worms in three adult stages (young adult stage, egg-laying stage and peak egg-laying stage) were investigated under 50 Hz, 3 mT ELF-EMF exposure. ATP levels, ATP synthase activity in vivo, reactive oxygen species (ROS) content, and changes of total antioxidant capacity (TAC) were detected, and worms' oxidative stress responses were also evaluated under ELF-EMF exposure. The results showed that ATP levels were significantly increased under this ELF-EMF exposure, and mitochondrial ATP synthase activity was upregulated simultaneously. In young adult stage, worms' ROS level was significantly elevated, together with upregulated TAC but with a decreased ROS-TAC score indicated by principal component analysis. ROS level and TAC of worms had no significant changes in egg-laying and peak egg-laying stages. Based on these results, we concluded that ELF-EMF can enhance worm energy metabolism and elicit oxidative stress, mainly manifesting as ATP and ROS level elevation together with ATP synthase upregulation and ROS-TAC score decrease in young adult C. elegans.

Comparative transcriptome analysis of salt tolerance mechanism of Meyerozyma guilliermondii W2 under NaCl stress.

A high-salt-tolerant strain, Meyerozyma guilliermondii, has been isolated from activated sludge which has a great effect in the treatment of high-salt wastewater. To identify the salt tolerance mechanism of the strain, transcriptome sequencing and fluorescence quantitative PCR were used to analyse and compare the thallus, which were growing in the salt-free, low-salt (4%), and high-salt (16%) YPD media for 48 h, respectively, and then the change of intracellular and extracellular glycerol was determined. The results showed that 8220 unigenes were obtained from the sequencing data after de novo splicing, among which 6334 genes had annotation information in the SwissProt library. With salt-free as reference, there were 1135 unigenes that differentially expressed under low-salt stress and 1948 unigenes were differentially expressed under high-salt stress. With low salt as reference, 3056 unigenes were differentially expressed under high-salt stress. The fluorescence quantification results of the six candidate genes selected in this study were consistent with the transcriptome data. Under high-salt stress, the intracellular glycerol of M. guilliermondii reached a maximum value at about 10 min, then decreased quickly and tended to be stable. This study provided valuable data for the next study of salt tolerance of M. guilliermondii, and also contributed to the functional study of yeast salt tolerance genes.

Oxidative dual C-H thiolation of imidazopyridines with ethers or alkanes using elemental sulphur.

Dual C-H thiolation reactions using elemental sulphur remain a challenge. This communication discloses an oxidative radical dual sp2/sp3 C-H thiolation strategy for the coupling of imidazopyridines with ethers or alkanes using elemental sulphur.

Isothiocyanation of amines using the Langlois reagent.

The Langlois reagent was found to be effective for the isothiocyanation of primary amines in the presence of copper iodide and diethyl phosphonate.