Studies On The Culture, Metabolites And Bioactivities Of Several Species Of Physarales Myxomycetes

In recent years,the research on myxomycetes has been paid more and more attention by most scholars.Nowadays,the study of life circle is becoming a hot research,it mainly includes: multinuclear and non-cell structure of the plasmodium stage and single nuclear fruiting stage,there are differences between different species.And different kinds of myxomycetes on the needs of different nutrients,so the growth status is different.Some of the monomeric compounds isolated from myxomycetes showed antibacterial,anti-tumor and cytotoxicity,the chemical composition of myxomycetes was also widely concerned.In this paper,the life cycle of two kinds of myxomycetes were described;the grain medium of 3 kinds of myxomycetes was compared;and the metabolites were analyzed and extracted,as well as the bioactivity was verified,which provided the basis for the discovery of better natural product resources.The main results are as follows:The life circle of Physarum rigidum and D.squamulosum of Physarales were observed by the method of combining with the moist chamber culture,hanging drop culture and agar culture.The morphological changes of different periods of this two kinds of myxomycetes were recorded,as well as the differences were compared.The difference between the two kinds of myxomycete is mainly as follows: the time required for the spore germination of Physarum rigidum is shorter than that of D.squamulosum,and the time of formation of the visible plasmodium is shorter and even if there is no natural light irradiation,the plasmodium of D.squamulosum will also form a fruiting body as well as the time required is shorter.Compares and analyzes the status of three kinds of myxomycetes Didymium squamulosum,D.megalosporum and Fuligo leviderma in six different grains(Sorghum rice,Rhubarb rice,Oats,Buckwheat,Corn,Pearl barley).The growth status of the three kinds of myxomycetes on the agar medium was recorded in 10 days as follows.From the fan area,the performance of D.squamulosum: Rhubarb rice > Sorghum rice > Oat > Pearl barley > Corn > Buckwheat > Water;the performance of D.megalosporum: Oat > Corn > Pearl barley > Rhubarb rice > Sorghum rice > Buckwheat > Water;the performance of F.leviderma: Rhubarb rice > Oat > Corn > Sorghum rice > Pearl barley > Buckwheat > Water.From the fanfront edge of the thick point of the view,the performance of D.squamulosum: Rhubarb rice > Sorghum rice > Oat > Pearl barley > Corn > Buckwheat > Water;the performance of D.megalosporum: Oat > Corn > Pearl barley > Rhubarb rice > Sorghum rice > Buckwheat > Water;the performance of F.leviderma: Rhubarb rice > Oat > Corn > Sorghum rice > Pearl barley > Buckwheat > Water.So in the future we can use rhubarb rice medium to culture D.squamulosum and F.Leviderma,and use oat medium to culture D.megalosporum.By the method of GC-MS,the liposoluble metabolites of six kinds of myxomycetes such as F.septica,F.leviderma,D.megalosporum,D.squamulosum,P.Rigidum and L.tigrinum were test.23 liposoluble metabolites were identified from F.Septica,16 liposoluble metabolites were identified from F.Leviderma;42 liposoluble metabolites were identified from D.megalosporum;15 liposoluble metabolites were identified from D.squamulosum;12 liposoluble metabolites were identified from P.rigidum;12 liposoluble metabolites were identified from Lepidoderma tigrinum.Different kinds of myxomycetes have the ability to produce the same type of liposoluble metabolites,Simultaneously,according to the analysis of the genetic relationship,similar species have the ability to produce the same metabolites.The metabolites of the dry plasmodium of the D.megalosporum were extracted by the method of ultrasonic extraction,Soxhlet extraction and Recrystallization.The structures of the metabolites were analyzed by 1H-NMR and 13C-NMR.Two metabolites were isolated from the plasmodium of this myxomycete,and compound 1 was stigmasterol and compound 2 was lactic acid.Both metabolites were isolated for the first time from this kind of myxomycete.The anti-tumor activity of the extracts of methanol and petroleum ether from the plasmodium of D.megalosporum was tested by CCK-8 kit,and the activity of methanol extract was higher than petroleum ether extract of D.megalosporum.The antibacterial activity of methanol and petroleum ether extracts of D.megalosporum were studied by the method of paper diffusion.Four kinds of bacterias were Escherichia coli,Salmonella typhimurium,Staphylococcus aureus and Bacillus subtilis.The results showed that the extracts of methanol and the extract of petroleum ether did not show a significant inhibitory effect on the four bacterias.