Pseudomonas Syringae Secondary Metabolite Studies

Pseudomonas syringae(Pseudomonas syringae pv.Lachrymans)belongs to the Prokaryotae,gracilicutes,pseudomonadaceae,Pseudomonas sp.,which is a kind of obligate aerobic gram-negative bacteria,and it’s widely distributed in soil,freshwater,seawater and organism.The current research on Pseudomonas syringae mainly focused on the molecular biology,genomics,proteomics,colony identification of Pseudomonas syringae and disease control,while the material basic studies on its secondary metabolites are rarely reported.Since Pseudomonas syringae can cause Panax notoginseng and other medicinal diseases,seriously affecting the quality and yield,whereas there is no effective approach to suppress Pseudomonas syringae,the mechanism of the secondary metabolites produced by Pseudomonas syringae is also unknown.In addition,according to the relevant reports,the secondary metabolites of microorganisms can inhibit or kill other microbes or other organisms at low concentration levels.In view of the above problems,it is necessary for us to study the secondary metabolites of Pseudomonas sp.,it is beneficial to discover new and biologically active compounds,and on the other hand,it can provide a scientific basis for the study of the relationship between microbial metabolites and their pathogenesis.Therefore,the following studies were carried out in this paper:Part one Literature reviewIn this paper,the study on the secondary metabolites of Pseudomonas at home and abroad over the past decades was reported,and reviewed the biological characteristics of the genus Pseudomonas,the classification status quo,classification and biological activities of secondary metabolites,provide scientific reference for further study of Pseudomonas and also provide theoretical for the study of the secondary metabolites and their biological activity of Pseudomonas.In recent years,an increasing number of cyclic dipeptides were isolated from bacteria,fungi,actinomycetes,plants and other organisms,The unique structure of cyclic dipeptides makes it have diverse biological activity,studies have shown that cyclic dipeptides not only have significant anti-bacterial and anti-tumor effects,but also play a key role in certain bacterial quorum sensing process,which is a hot research topic in the study of chemical ecology.This paper reviews the biological activity roports of cyclic dipeptides over the past decades,in order to provide a scientific basis for the activity research of cyclic dipeptides.Part two Study on the secondary metabolites of Pseudomonas sp.By means of TLC,normal phase silica gel column chromatography,reverse phase MCI,ODS,Sephadex LH-20 and other chemical separation means,19 compounds were isolated from the fermentation broth of Pseudomonas sp.,which was extracted with chloroform and ethyl acetate.Through 1H-NMR,13C-NMR,DEPT,1H-1H COSY,HMQC,HMBC,ESI-MS date assignments,comparing with literature and GC-MS analysis,ultimately identified 19 compounds,including 10 cyclic dipeptide compounds:Cyclo(L-Pro-Gly)(1),Cyclo(L-ProL-Ala)(2),Cyclo(L-Pro-L-Val)(3),Cyclo(L-Pro-L-Leu)(4),Cyclo(L-4-hydroxy-Pro-LLeu)(5),Cyclo(Tyr-Leu)(6),Cyclo(Pro-Trp)(7),Cyclo(L-Val-L-Leu)(8),Cyclo(Val-Ile)(9),Cyclo(Leu-Ile)(10),One phenazine alkaloids:Phenazine-1-carboxylic acid(11),Two indole alkaloids:Indole-3-ethanol(tryptophol)(12),Indole-3-acetic acid methyl ester(13),Four benzene ring-containing compounds:P-hydroxyphenyl ethanol(14),Disisobutyl phthalate(15),Phenylacetate(16)and Phenol(17),One Fatty acid compound:Hexadecanoic acid(18),and Acetic anhydride(19).The compound 1-19 was isolated from the fermentation broth of Pseudomonas syringae for the first time,and in which compounds 6,9,14,16,17,18,19 were isolated from this genus for the first time.The compounds isolated from the fermentation broth of Pseudomonas syringae are mainly cyclic dipeptides,10 in total.Cyclic dipeptide,also known as 2,5-diketopiperazine,is composed of two amino acids by peptide bonds formed by condensation,is the smallest cyclic peptide in nature.This kind of compounds has distinct and novel structure,and plays a key role in anti-tumor drug screening.Herein,the isolated cyclic dipeptides 1-10 were first discovered from this bacterium,in which cyclic dipeptides Cyclo(Tyr-Leu)(6)and Cyclo(Val-Ile)(9)were isolated from the genus for the first time.These compounds are a new source for antimicrobial and antitumor drug screening.In addition,the alkaloids,benzene ring-containing compounds,fatty acids and acetic anhydride,were isolated from the fermentation broth of pseudomonas syringae,and also greatly enriched the chemical composition and type of the genus Pseudomonas,which laid the material foundation for the further study of the biological activity.InnovationThis project is the first time to explore the material basis of the secondary metabolites of Pseudomonas syringae,through the different polar solvent extraction and separation of the fermentation broth of Pseudomonas syringae,on the one hand lay the material basis for exploring new and biologically active compounds,it also provides a scientific basis for exploring the relationship between microbial metabolites and their pathogenesis.