New diketopiperazine alkaloid and polyketides from marine-derived fungus Penicillium sp. TW58-16 with antibacterial activity against Helicobacter pylori.

Marine-derived fungi can usually produce structurally novel and biologically potent metabolites. In this study, a new diketopiperazine alkaloid (1) and two new polyketides (10 and 11), along with 8 known diketopiperazine alkaloids (2-9) were isolated from marine-derived fungus Penicillium sp. TW58-16. Their structures were fully elucidated by analyzing UV, IR, HR-ESI-MS, 1D, and 2D NMR spectroscopic data. The absolute configurations of the new compounds 1, 10 and 11 were ascertained by X-ray diffraction (Cu Kα radiation) and comparing their CD data with those reported. In addition, the antibacterial activities of these compounds against Helicobacter pylori in vitro were assessed. Results showed that compounds 3, 6, 8 and 9 displayed moderate antibacterial activity against standard strains and drug-resistant clinical isolates of H. pylori in vitro. This result demonstrates that diketopiperazine alkaloids could be lead compounds to be explored for the treatment of H. pylori infection.

A new antibacterial 3,5-dimethylorsellinic acid-based meroterpene from the marine fungus Aspergillus sp. CSYZ-1.

Chemical investigation of the extracts of Aspergillus sp. CSYZ-1 resulted in the identification of compound 1, aspergillactone, a new 3,5-dimethylorsellinic acid-based meroterpenoid, together with four known metabolites (2-5). The structure and relative configuration of 1 were unambiguously determined by nuclear magnetic resonance (NMR), mass spectrometry. The absolute configuration of 1 was defined by quantum chemical TDDFT calculated and the experimental ECD spectra. The possible biosynthetic pathway of compound 1 was also proposed. The new compound exhibited potent antimicrobial activity against Helicobacter pylori and Staphylococcus aureus with MIC values of around 1-4 and 2-16 µg/mL, respectively.

Genes Induced by Panax Notoginseng in a Rodent Model of Ischemia-Reperfusion Injury.

Stroke is a cerebrovascular disease that results in decreased blood flow. Although Panax notoginseng (PN), a Chinese herbal medicine, has been proven to promote stroke recovery, its molecular mechanism remains unclear. In this study, middle cerebral artery occlusion (MCAO) was induced in rats with thrombi generated by thread and subsequently treated with PN. After that, staining with 2,3,5-triphenyltetrazolium chloride was employed to evaluate the infarcted area, and electron microscopy was used to assess ultrastructural changes of the neurovascular unit. RNA-Seq was performed to determine the differential expressed genes (DEGs) which were then verified by qPCR. In total, 817 DEGs were identified to be related to the therapeutic effect of PN on stroke recovery. Further analysis by Gene Oncology analysis and Kyoto Encyclopedia of Genes and Genomes revealed that most of these genes were involved in the biological function of nerves and blood vessels through the regulation of neuroactive live receptor interactions of PI3K-Akt, Rap1, cAMP, and cGMP-PKG signaling, which included in the 18 pathways identified in our research, of which, 9 were reported firstly that related to PN's neuroprotective effect. This research sheds light on the potential molecular mechanisms underlying the effects of PN on stroke recovery.

Chemistry and bioactivities of secondary metabolites from the genus Fusarium.

A growing body of evidence suggests that endophytic fungi represent a huge and largely untapped resource of natural products with novel structures and biodiversity that have been optimized by evolution for biological and ecological relevance. Fusarium species, known as the chief criminal of causing quality and yield reductions of grain crops, is a large genus of filamentous fungi with worldwide distribution. The chemical structures of 162 metabolites isolated and characterized from Fusarium species during the past six years are presented along with information of their biological activities. Biosynthesis of some biologically important mycotoxins are also reviewed.