Studies Of Secondary Metabolites From An Endophytic Fungi R22 Of Nerium Indicum

The research object of this experiment is the strain R22,which was isolated from the root of Nerium indicum with higher antimicrobial activities.The morphological characteristics and molecular biology characteristics revealed that the strain R22 is penicillium.The strain R22 was fermented by the rice solid medium.The loftdried culture was extacted with ethyl acetate and methanol to afford crude extract.The compounds were purified by silica gel column chromatography,gel column chromatography and recrystallization methods.Their structures were identified according to physicochemical property,spectrum data,high resolution mass spectrometry,infrared spectrum,ultraviolet spectrum and X-single crystal diffraction.Twenty compounds were identified as 26 alkyl acid(1),ergosterol(2),peroxy-ergosterol(3),3-O-methylviridicatin(4),succinicacid(5),daturic acid-2,3-dihydroxypropylester(6),3-methylquinazolin-4(3H)-one(7),4-hydroxy-3,6-dimethyl-2-pyrone(8),viridicatol(9),cyclopenol(10),5-hydroxy-8-methoxy-4-phenylisoquinolin-1(2H)-one(11),daucosterol(12),4-(2’R,4’-dihydroxyb--utoxy)benzoic acid(13),Aurantiomide C(14),arabite(15),Cyclo-(L-tryptoph--yl-L-phenylalanyl)(16),mannitol(17),erythritol(18),allantoin(19),adenosine(20).5-hydroxy-8-methoxy-4-phenylisoquinolin-1(2H)-one(11)and 4-(2’R,4’-dihydroxybutoxy)benzoic acid(13)were new compounds,3-methylquinazolin-4(3H)-one(7)was isolated from the natural world for the first time.For the antimicrobial activity test of four bacterias(Streptococcus lactis,Staphylococcus aureus,Pseudomonas aeruginosa,Escherichia coli)and ten fungis(Fusarium graminearum,Setosphearia turcica,Colletotrichum gloeosporioides,Alternaria alternata,Alternaria brassicae,Sclerotinia sclerotiorum,Botrytis cinerea,Phytophthora capsici,Valsa Mali,Peony anthracnose),3-O-methylviridicatin(4)and viridicatol(9)shown better inhibition to fungi and bacteria.5-hydroxy-8-methoxy-4-phenylisoquinolin-1(2--H)-one(11),4-(2’R,4’-dihydroxybutoxy)benzoic acid(13)and allantoin(19)shown better inhibition to bacteria.This paper focused on the study of the fermentation of endophytic fungi strain R22 from Nerium indicum.A total of 20 compounds were isolated and purified from fermentation culture,among them compound 11 and 13 were new compounds.The antimicrobial activity test showed that compounds 4 and 9 revealed strong antimicrobial activity on plant pathogenic fungi and bacteria.The study showed that the strain has the potential to generate new compounds.Compound 19 and two new compounds 11 and 13 revealed strong antibacteria activity,showed that endophytic fungi R22 is a potential natural resources,which will become an important sources for new drugs development.