The Secondary Metabolites From A Strain Of Endophytic Fungus Phyllosticta Sp.Obtained From Acorus Tatarinowii.

Acorus tatarinowii is one of the common and important medicinal plants,its dried rhizomes have a long history of being used as traditional Chinese medicine(TCM),which is rich with asarones that show antimicrobial activity.For the existence of abundant antimicrobial asarones in A.tatarinowii,the micro-environment is special and the microorganisms living in this habitat should be distinctive.,which make it possible to produce metabolites with novel structures or bioactivity.Therefore,a chemical investigation on the culture media of an endophytic fungus Phyllosticta sp.J13-21-12 Y obtained from Acorus tatarinowii.was carried out.Twenty compounds were obtained from the extract of Phyllosticta sp.J13-21-12 Y fermented with rice.Their structures were determined by detailed spectroscopic analysis,ECD experiments,X-ray,chemical derivation,quantum chemical calculation,etc.Seven of these compounds were new compounds,including three guignardianone–guignardone type meroterpenoids(1-3),four 4-phenyldihydrofuran-2(3H)-ones(15a,16 a,16b,17b).The antimicrobial activities of twenty compounds were evaluated by dilution method,and some compounds exhibited different antimicrobial activities.Among them,4-phenyldihydrofuran-2(3H)-ones and phenguignardic acid methyl ester(6)showed potent activity against Staphylococcus aureus 209 P and Candida albicans FIM709.Guignardianone–guignardone type meroterpenoids(1-3)are the first multi-biosynthetic derived meroterpenoids,whose structures are composed of one guignardianone unit from amino acid pathway,one monoterpene unit from terpenoid pathway,and one C7 unit from pentose phosphate pathway.It’s first time to found three mixture of enantiomers of 4-phenyldihydrofuran-2(3H)-ones from Phyllosticta sp.,all of these enantiomers were separated by chiral HPLC.Furthermore,the absolute configurations of these compounds were determined by CD experiments and CD calculation,and 4 new compounds were obtained.