Study On Antibacterial And Antifungal Activities Of Four Natural Products From Medicinal Fungi In Vitro

Medicinal fungi contain a series of natural products, which have pharmacological activity and physiological activity. Some natural products also have better antibacterial and antifungal activity. Therefore, it is an effective way to develop new pesticide pollution-free for looking for the antimicrobial active substance from medicinal fungi, which can provide the experimental basis of the further processing and synthesis of biological pesticides.Sarcodon scabrosus belongs to the family hydnaceae. It was reported in the literature, the fruiting body contains a series of cyathane type diterpenoids, which have a good antibacterial activity. Hericum erinaceus, a kind of well-known fungi as edible and medical fungi, contains a variety of chemical components and the unique secondary metabolites and has a good applicational value.In this dissertation, the chemical constituents in the fruiting bodies of Hericum erinaceus were studied by other conventional chemical methods and techniques containing solvent extraction, column chromatography, crystallization and thin layer chromatography. Four compounds, are 4 - ( 3’, 7’- dimethyl - 2’, 6’ - octadienyl ) - 2- formyl - 3 - hydroxyl - 5 - methoxybenzyl alcohol l - palmitate ( hericene A, compound 1 ), 4- ( 3’, 7’ - dimethyl - 2’, 6’- octadienyl ) - 2 - formyl - 3 - hydroxyl - 5 - methoxybenzyl alcohol - linoleate ( hericene D, compound 2 ), 3β- hydroxy - ergosta - 5, 7, 22 - triene ( ergosterol , compound 3 ), 3β- hydroxy - 5α, 8α- epidioxyergosta - 6, 22 - diene ( ergosterol peroxide, compound 4 ), which were obtained from HE EtOAc of the methanol extract of the fruiting bodies of Hericum erinaceus, and were analyzed by four identified physical constants, chemical method and spectral analysis. Compound 1 and compound 2 are phenolic compounds with fatty acid side chain and benzene ring structure. The compound 2 with linoleic acid side chain, which has the same mother nucleus structure as the hericenes, was found by our group. Compound 3 and compound 4 belong to ergosterol. Ergosterol is more in the large-scale fungus, and has no inhibition on bacteria and plant pathogenic fungi, and were used to synthesize ergosterol peroxide.The antibacterial and antifungal activities of scabronine G, scabronine H, ergosterol peroxide and hericene A in vitro were studied.In the antibacterial test, the streptomycin on a variety of bacteria had a very strong activity in the three concentration gradient. At the concentration of 1mg/ml, both scabronine G and scabronine H showed significant activity against the five tested bacteria, especially scabronine G which was almost close to the intensity of the same concentration of the antibacterial activity of streptomycin. The results showed the wide range of antibacterial activity. In addition, both ergosterol peroxide and hericene A displayed lower inhibitory activity than scabronine G and scabronine H at the same concentration. However, ergosterol has almost no inhibition activity.In the experiment of inhibition to mycelial growth of plant pathogenic fungi. At the concentration of 1mg/ml, carbendazim showed high inhibition rate against these six pathogenic fungi. The highest inhibition rate was to 88.23%, against Sclerotiorum sclerotiorum. Scabronine G and scabronine H also showed a high antifungal activity.Scabronine H, which had higher activity than scabronine G, reached the inhibition rate of 75.99%, while ergosterol peroxide, hericene A and ergosterol had no significant inhibition against these six fungi. At the concentration of 1×10-1mg/ml, inhibition activity of carbendazim and these other samples became very weak. It is of great practical significance that antibacterial and antifungal activity of scabronine G and scabronine H of cyathane type diterpenoids is expected to explore its antimicrobial mechanism and provide some preliminary information to develop new microbial fungicides.