Scarcity Of Medicinal Plants Xiaowan Periwinkle Study Of Endophytic Fungi In The Production Of Active Ingredients,

Ten strains of endophytic fungi were isolated from the stems, roots and leaves of a rare medicinal plant Vinca minor Linn.According to the characteristic color reactions of alkaloids, one strain, XM-J2 with the ability to produce alkaloids were screened out in the preliminary selection. Then the strain was further selected by thin layer chromatography (TLC). And the experimental results showed that XM-J2 fermentation broth extract has the same R_f value in TLC analysis as that of standard vincamine.Based on the above experiments, the procedure of vincamine extraction was optimized. Through silica gel column chromatography (CC), 50% methanol is served as eluent agent. A further UV spectrometry and high-performance liquid chromatography (HPLC) showed that one ingredient of the extract from the strain XM-J2 had a similar absorption curve in the wavelength range of 200-500nm and the same retention time as vincamine. The structure of the sample was confirmed by using the IR, ¹H-NMR,H-HCOSY .The results showed that the sample should contained the bioactive ingredient vincamine like its host plant Vinca minor.Using the biomass and vincamine yield as indexes, an optimum liquid medium . potato-sucrose medium was selected out; the maximum yield of vincamine in this medium was 0.64 mg·L^-1. Then, by changing different carbon source, nitrogen source and culture temperature, optimal culture conditions were selected. The suitable conditions for both mycelial growth and vincamine production are: potato-sucrose medium with sucrose, peptone, and the temperature about 28℃, respectively. The fermentation conditions of XM-J2 were further potimized by the orthogonal experiment of L16 (4³) . The results showed that sucrose 50 g/L, peptone 1 g/L, pH about 7.0 and the temperature about 28℃, the liquid medium quantity about 85～90 ml/250 ml were the optimum conditions for its mycelial growth and were suitable for vincamine production.The strain XM-J2 was classified primarily according to its morphological characters. XM-J2 should be a strain belonging to the Fungi Imperfecfi, Hyphomycetes, Agonomycetales.