Studies On The Chemical Constituents And Liquid Fermentation Optimization Of Endophytic Fungus AS5 Isolated From Aquilaria Sinensis

An endophytic fungus (No. AS5) isolated from Aquilaria sinensis (Lour.) Gilg was identified asPreussia sp. which showed antimicrobial activities. On the basis of classical chemical methods andmodern spectroscopic analysis the chemical, constituents of Preussia sp. were studied guided by theantimicrobial activity screening. Compound CH was found to be the antibiotic component in Preussiasp. It's HPLC analysis method was studied, which established the basis of liquid fermentation optimization.Thirteen compounds were isolated from the fermentation material of Preussia sp. and twelve of themwere determined. They were spiro-preussione A (CH), spiro-preussione B (EA₂), spiro-preussomerin A(EA3), 9-hydroxyphenalenone (PE2), ergosterol (PE1), butanedioic acid (EA1), 5-hydroxymethyle-2-furfurahede (EA6), D-mannitol (B1), D-allitol (B2), B3, uridine (B5), adenosine (B6). Compund Ctt,EA2, EA3 were new compounds and compound PE2 was firstly isolated from Preussia sp.Compounds CH showed moderately activity aganist Staphylococcus aureus (MIC: 8μg/mL), whichalso suggested cytotoxic activity against Bel-7402 (human liver tumor cell line) and A2780 (humanovarian tumor cell line) with IC₅₀ values of 0.95 and 0.77μg/mL, respectively.The suitabale medium and culture condition for fungus AS5 to accumulate compound CH wereD-glucose 20 g/L, wheat bran 15 g/L, KH2PO4 3 g/L, MgSO4 1.5 g/L, incipient pH 7, inoculation 4-8fungal plate (Φ9 mm), 100-125 mL medium/250 ml triangular flask, temperature 25-28℃, rate ofrotation 120 rpm, culturing for 16 days in dark.