title: Biotransformation of ursolic acid by an endophytic fungus from medicinal plant Huperzia serrata.
abstract: Endophytic fungi were used not only for their producing bioactive products but also for their ability to transform natural compounds. An endophytic fungus, isolated from medicinal plant Huperzia serrata, was identified as Umbelopsis isabellina based on the internal transcribed spacer of ribosomal DNA (rDNA-ITS) region. It was used to transform ursolic acid (1), a pentacyclic triterpene. Incubation of ursolic acid with U. isabellina afforded three products, 3β-hydroxy-urs-11-en-28,13-lactone (2), 3β,7β-dihydroxy-urs-11-en-28,13-lactone (3), 1β,3β-dihydroxy-urs-11-en-28,13-lactone (4). Although product 2 was a known compound, it was first obtained by microbial transformation. Products 3 and 4 were new compounds. The structural elucidation of the three compounds was achieved mainly by the 1D- and 2D-NMR, MS, IR data. The endophytic fungus U. isabellina can hydroxyate the C12-C13 double bond at position 13 of ursolic acid 1 and form a five-member lactone effectively. In the meantime, this fungus can also introduce the hydroxyl group at C-1 or C-7 of ursolic acid 1.
authors: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
authors: Shao-bin
authors: SB
authors: Fu
authors: Jun-shan
authors: JS
authors: Yang
authors: Jin-long
authors: JL
authors: Cui
authors: Xu
authors: X
authors: Feng
authors: Di-an
authors: DA
authors: Sun
mesh_terms: D001711:Biotransformation; D032501:Huperzia / Q000382:microbiology*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008968:Molecular Conformation; D009090:Mucorales / Q000235:genetics / Q000378:metabolism*; D010946:Plants, Medicinal / Q000382:microbiology; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013055:Spectrophotometry, Infrared; D014315:Triterpenes / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D000097245:Ursolic Acid
chemical_list: D012336:RNA, Ribosomal, 16S; D014315:Triterpenes; D000097245:Ursolic Acid; C568984:1beta,3beta-dihydroxy-urs-11-en-28,13-lactone; C568983:3beta,7beta-dihydroxy-urs-11-en-28,13-lactone