Investigation On The Secondary Metabolites And Activities Of Four Actinomycetes Strains Related Medicinal Plants

Objective: to study the secondary metabolites and activities of four actinomycetes strains including Streptomyces sp.KIB-H869 in Dracaena cochinchinensis,a soil-derived Streptomyces pactum KIB-HL8 from arid Habitats,Streptomyces.sp.KIB-H339 from Panax notoginseng rhizosphere soil in Wenshan county,Yunnan province and the heterologous expression strain S.albus 9B10 from rubrolone biosynthetic gene cluster in Camellia sinensis endophyte.Methods: Their metabolites were isolated and purified by organic solvent extract,silica gel column chromatography,HPLC and Sephadex LH-20 chromatography,etc.Their structures were established on the basis of extensive spectroscopic methods including MS,1D-NMR,2D-NMR(1H-1H COSY,HSQC,HMBC,ROESY).The inhibitory activities of compounds were tested in vitro against plant pathogenic fungi and bacteria by paper disk method,respectively.Results: Thirty-two compounds,including seven new ones,were isolated and identified from the above mentioned actinomycetes strains.(1)Seven compounds were isolated from the endophyte Streptomyces sp.KIB-H869 in Dracaena cochinchinensis and identified as hygrolidintype acrolide(1),Oxohygrolidin(2),Elaiophylin(3),11-O-monomethylelaio-phylin(4),6-Prenylindole(5),Azalomycins F4a(6),Azalomycins F5a(7).Moreover,by the biogenesis ratiocination and NMR data comparison,halichomycin and 2 were confirmed to have the same structure,which corrects the structural misrepresentation of halichomycin;(2)Five compounds,N-Acetyramine(8),N-acetyltryptamine(9),pyrrole-2-carboxamide(10),Inthomycin C(11)and Inthomycin B(12),were isolated from the fermentation broth of Streptomyces pactum KIB-HL8;(3)From Streptomyces Sp.KIBH339,nine compounds were isolated and identified as Rubiginone D2(13),Rubiginone A2(14),(+)-Rubiginone B2(15),3-(2-Hydroxyethyl)Indole(16),1-H-Indole-3-carboxaldehyde(17),L-tryptophan(18),2,4-Bis-(1-methyl-1-phenylethyl)phenol(19),2-(4-Hydroxyphenyl)ethanol(20),2-(4-Hydroxypheny1)-2-oxoethanol(21);(4)From the heterologous expression strain S.albus 9B10 from rubrolone biosynthetic gene cluster,eleven compounds were isolated and identified as rubrolone aglycon(22),Rubrolone biosynthetic intermediates(23,24,27,28),Rubrolones C(25),Rubrolones D(26),R1128 A(29),7-hydroxy-2-((4-hydroxy-2-oxo-2H-pyran-6-yl)methyl)-5-propyl-4H-chromen-4-one(30),Norcardamine(31),2-hydroxy-3-methyl-4H-pyran-4-one(32).Conclusions: These compounds include anthraquin ones,alkaloids,macrolides,amino acids,et al(Figure 1).compounds 1,23,24,25,26,27,28 were new compounds.The results inhibitory activities of compounds indicated that macrolides showed broad and potent antifungal activities.