title: Studies on a rhein-producing endophytic fungus isolated from Rheum palmatum L.
abstract: Rheum palmatum L. (Chinese rhubarb) is a highly regarded medicinal plant. Its dominant active constituents are anthraquinones including emodin, aloe-emodin, rhein, etc. Rhein naturally occurs in anthraquinone (1, 3, 8-trihydroxy-6-methyl anthraquinone), which is found in R. palmatum L. and related plants such as rhubarb. It has good antitumor, anti-inflammatory, anticancer, antimicrobial and hemostatic properties. In this study, a total of 14 strains of endophytic fungi were isolated from R. palmatum L. All fungal isolates were fermented in liquid PDA medium and their extracts were preliminarily analyzed by antibacterial reactions, magnesium acetate-methanol reagent and Borntraiger's reaction, and the strain reselection was made by thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC) and LC-MS to identify the fermentation products of the selected strains and confirmed through a comparison with authentic standards. Extract from one strain, R13, showed positive reactions with both reagents. The strain R13 had a component with the same TLC (Rf) value and HPLC, LC-MS retention time as authentic rhein standards. The yield of rhein in R13 can reach 5.672mgl(-1). The fungi were identified as Fusarium solani by using both ITS rDNA sequencing and spore morphology.
authors.affiliation: Key Laboratory of Biological Resource and Ecological Environment of the Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China.
authors.forename: Xia
authors.initials: X
authors.lastname: You
authors.forename: Su
authors.initials: S
authors.lastname: Feng
authors.forename: Shenglian
authors.initials: S
authors.lastname: Luo
authors.forename: Dingding
authors.initials: D
authors.lastname: Cong
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Yu
authors.forename: Zhirong
authors.initials: Z
authors.lastname: Yang
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000880:Anthraquinones / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D060026:Endophytes / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D013058:Mass Spectrometry; D008826:Microbial Sensitivity Tests; D010946:Plants, Medicinal / Q000382:microbiology; D012250:Rheum / Q000382:microbiology*
chemical_list: D000880:Anthraquinones; C020491:rhein