The Active Metabolites From Endophytic Niarospora Oryzae Cocultured With Irpex Lacteus

Dendrobium officinale belongs to orchidaceae and used as Chinese herbal medicine.All orchids require fungi to provide inorganic and organic nutrients for seed germination and early seedling development.Therefore,we concluded that the metabolism of endophytes from Dendrobium officinale should be stronger than other endophytes.This paper mainly studied the secondary metabolites and activities of the co-cultured endophytic fungus Nigrospora oryzae and Irpex lacteus from Dendrobium officinale.The content of the paper was divided into four chapters:The first chapter reviewed the progress of secondary metabolites and biological activities of JV/grospora and Trpex;and the antibacterial activity of compounds from Penicillium.The second chapter was mainly about the screening and design of the target strain.19 endophytic fungi were isolated from the seeds of Dendrobium officinale collected from Wenshan,Yunnan.TLC screening of 19 endophytic fungi was carried out,and 2 endophytic fungi were screened out,which were strain 1(TPZ-30),and strain 23(TPZ-10-1).).The two endophytic fungi were mixed and cultured,and the chemical diversity of the secondary metabolites co-cultured by strain 1(TPZ-30)and strain 23(TPZ-10-1)was increased by TLC.The strain TPZ-30 and TPZ-10-1 were identified by ITS sequence determination as Irpex lacteus and Nigrospora oryzae.The third chapter was mainly about the secondary metabolites and biological activities of the liquid co-culture of the endophytic fungus Nigrospora oryzae and Irpex lacteus.Fourteen compounds were isolated and identified in the liquid co-culture.There are 5 new compounds:nigripexin A(1*),nigirpexin B(2*),nigirpexin C(3*),nigirpexin D(4*),nigrosirpexin A(5*),and 9 known compounds:dermatolactone(6),tremulenediols A(7),scytalone(8),11,12-dihydroxy-1-tremulen-5-one(9),ergos-terolperoxide(10),conocenol B(11),conocenol C(12),4a,11,12,14-tetrahydroxy-1-tremulene(13),14-acetoxy-15-hydroxyirpexan(14).Compounds 4*,5*,7 showed antibacterial activity.Compounds 5*,7 showed antibacterial activity against the endophytic fungus Nigrospora oryzaey,with MICs at 64 ?g/mL and 16?g/mL,weak antibacterial activity against Irpex lacteus,with MICs at 128 ?g/mL,no antibacterial activity against Candida albicans and Bacillus subtilis.Compound 4*showed weak antibacterial activity against endophytic fungus Irpex lacteus,with MICs at 256 ?g/mL,and showed no antibacterial activity against endophytic fungus Nigrospora oryzaey,Candida albicans and Bacillus subtilis.The anti-tumor cytotoxic activity,NO inhibition,lipase activity,tyrosinase activity and anti-AChE of compound 1*,5*were investigated.Compound 5*indicated anti-AChE activity with inhibition ratio at 35.02%in the concentration of 50 ?M.The fourth chapter was mainly about the secondary metabolites and biological activities of the mixed solid culture of Nigrospora oryzae and Irpex lacteus.Through the preliminary isolation and extraction,we studied the modification of endophytic fungi Nigrospora oryzae and Irpex lacteus in liquid co-culture medium(sweet potato,yam,taro)and time(7,10,14 days).Experiments showed that changes different medium and time have little effect on secondary metabolism of endophytic fungi.Therefore,the endophytic fungi Nigrospora oryzae and Irpex lacteus of Dendrobium officinale were mixed cultured in solid medium,and six known eompounds were isolated and identified:?-sitosterol-3-O-?-D-glucopyranoside(1),(205,22E,24R)-ergosta-7,22-dien-3?,5?,6?-triol(2),(+)-(35,6R,7R)-tremulene-6,11,12-triol(3),asperamide A(4),4-(4 dihydroxymethylphenoxy)benzaldehyde(5),nigbeauvin A(6).Compound 5*showed selectivity of antifungal activities against endophytic fungus Nigrospora oryzaey,with MICs at 16 ?g/mL,weak antibacterial activity against Irpex lacteus,with MICs at 256 ?g/mL.