Study on Secondary Metabolites of Talaromyces sp., an Endophytic Fungus in Gouteng
Uncaria rhynchhophylla (Miq.) Miq Ex Havil. is a thorny plant belonging to the Gentianaceae order of the Rubiaceae family. It is named after the downward single or double hooks on its nodes, and is often used as medicine with dry hooked stems and branches. Gouteng plants have the effects of clearing heat and calming the liver, calming the wind and calming the nerves. Modern pharmacology has shown that plants of the Gouteng genus are effective in treating cardiovascular and central nervous system diseases, and have also shown good results in cancer treatment.

Endophytic fungi in plants form a stable symbiotic relationship with their host plants through long-term co evolution. On the one hand, endophytic fungi can absorb nutrients from host plants for their own growth; On the other hand, endophytic fungi can have a positive impact on host plants through their own secondary metabolites or through signal transduction. In recent years, a large number of literature reports have isolated a series of bioactive monomeric compounds from the secondary metabolites of endophytic fungi. Obtaining natural products through fungal metabolism has significant advantages in yield, economy, and environmental protection.

Talaromyces sp. 1.88E belongs to the genus Talaromyces fungi. Literature reports have isolated many novel skeletal structures from the metabolites of Talaromyces sp., which are compounds with significant anti-inflammatory, anti-tumor, and antibacterial activities. This study focuses on the endophytic fungus Talaromyces sp.1.88E isolated from Gouteng, and uses rice culture medium for fermentation in order to isolate monomeric compounds with good biological activity from its fermentation products. This is of great significance for screening new drugs and developing new pharmaceutical resources.

 

 

In this experiment, various chromatographic methods were used to isolate 8 compounds from the fermentation products of the endophytic fungus Talaromycessp.1.88E in Gouteng. Among them, compound 1 is a new compound, and compound 2 is the first reported NMR data. We conducted anti-inflammatory activity and alpha glucosidase activity tests on compounds 1-8, and only compounds 2 and 6 showed inhibitory effects on alpha glucosidase activity. Compounds 5 to 8 are all compounds of the mycorrhizal class, and the slight differences in substituents of mycorrhizal compounds have a significant impact on their activity. Only compound 6 exhibits weak inhibitory effects on alpha glucosidase. The only difference between compound 6 and compound 7 is that the OH at position 5 of the A ring changes to OCH3, while the OH at position 5 of the A ring in compounds 5 and 8 is also OCH3, indicating that the OH at this position may play a decisive role in alpha glucosidase activity. In summary, this study lays the foundation for further exploring the active ingredients in the fermentation products of endophytic fungi in Gouteng. By testing the inhibitory effect of isolated monomeric compounds on LPS induced NO production and α – glucosidase activity in RAW 264.7 cells, the structure-activity relationship between compounds is explored, providing certain reference significance for the development of natural active compounds.