Polyketones in endophytic fungus Alternaria malvae from Salvia miltiorrhiza
Objective To study the secondary metabolites and its biological activities of the endophyties Alternaria malvae derived from the roots of Salvia miltiorrhiza.Methods Preparative high-performance liquid chromatography,along with additional chromatographic techniques including normal-phase column chromatography,MPLC-ODS,MCI,and Sephadex LH-20,was employed to isolate and purify the secondary metabolites.NMR and mass spectrometry were then used to characterize the individual compounds.Results A total of seven compounds were isolated from the rice fermentation of A.malvae and identified as 3-methoxyalternolide B(1),4'-epialtenuene(2),(+)-(4'R,5'S,7'R)-altenuene(3),4'-epi-dihydroaltenuene A(4),alternariol 5-methyl ether(5),alternariol(6)and altenuisol(7).Compound 1 was a new compound,Compounds 5 and 7 exhibited anti-inflammatory activity with IC50 values of(14.8+0.67)μmol/L and(27.76+2.75)μmol/L,respectively.Conclusion Compound 1 is a new polyketone compound named 3-methoxyalternolide B.Compound 5 has significant anti-inflammatory activity.