Research On Secondary Metabolites Of Undifilum Oxytropis And Its Optimization On Fermentation Condition

Fungal endophytes of plant exist in the organization of their hosts at some stage or the whole life cycle. The fungal endophytes have doeveloped a unique metabolic patways during the long term of conevolution with host, they not only can generate similar compounds to host,but also can produce other novel compounds, thus fungal endophytes are regarded as one of the most important medicinal compound repository. This paper focused on the Undifilum oxytropis isolated from locoweeds, the secondary metabolites were analyzed by using fermentation, separation and purification of metabolites, spectroscopic analysis(GC, GC-MS,LC-MS) techniques. Meanwhile, The optimal screening of fermentation conditions have also been conducted. This provide an important theoretical basis for the bioavailability of Undifilum oxytropis. The results are as follows:1. System pre-test results appeared that fermentative product contains alkaloids, proteins,phenols, tannins, flavonoids, quinones, volatile oil and grease.2. The fermentation system of Undifilum oxytropis was detected through TLC method,which contained 5 compounds at least. And similar compounds are present in the fermentation broth and mycelium. What matters more is that SW and its analogues indwell in butanol phase of mycelium and broth. Further analysis by GC results that the contents of swainsonine in the fermentation broth and mycelium were 5.17×10-3 g.L-1 and 0.466 mg.g-1 respectively.3. GC-MS was applied to analyse Undifilum oxytropis fermentation products derived from petroleum ether, chloroform phase and ethyl acetate, the results showed these three phase contained 59, 64 and 35 kinds of compounds respectively, among which there are 105 kinds of different compounds, and most of them are alkanes, esters. In addition, there are some high concentration sompounds couldn’t know the spectific structure due to the limited detection technique, so the further analysis is needed. LC-MS result indicated that Undifilum oxytropis fermentation product contained 5 alkaloids including SW, Oxynitride swainsonine,Lentiginosine, Retronecine and 2-Hydroxy-indolizidine. And after acetylated have undergone varying degrees of acetylation, wherein the latter three alkaloid were firstly isolated from Undifilum oxytropis, which also provides some theoretical basis for swainsonine are fungaloriginal secondary metabolites.4. Orthogonal experiment conducted that among four factors of Undifilum oxytropis, the temperature is the key factor. the optimum proportion for the maximum mycelium yield, the highest SW content of fermentation liquid, the highest SW content of mycelium is 30 °C, 40 d,0.5×10-3 mol.L-1 L-lysine and 10-4 mol.L-1 L-pipecolic acid; 30 °C, 40 d, 2.0×10-3 mol.L-1 的L-lysine and 10-3 mol.L-1 L-pipecolic acid; 30 °C, 40 d, 0.5×10-3 mol.L-1 L-lysine and 10-5mol.L-1L-pipecolic acid respectively.In summary, the above results showed that Undifilum oxytropis isolated from locoweed contained a variety of secondary metabolites, what matters more is that SW and its analogues indwell in butanol phase of mycelium and broth, which provided a theoretical basis for the futher study of SW biosynthetic pathway of Undifilum oxytropis. We also obtained the optimizational fermentation condition for the high SW production, which laid the foundation for transformation from laboratory to industrial production.