| Secondary metabolism is an adaptability metabolic pathway in plant response to changed environmental factors, which is a flexibility reaction in self defensive, and is a meaning for ecology adaptability and living space by plant self-regulation. However, relative to human, major plant secondary metabolism substances have efficacy in cure disease as main source of pharmacology and chemical products. In fact, the contents of various secondary metabolism used in medicalis increased obviously after environmental factors changed and medical plant stimulated. Even some new medical substances are produced and these play distinct chemical defense role for plant.1-deoxynojirimycin (DNJ) is a piperidine alkaloid which produced by secondary metabolites in mulberry and could restrain a-1,4glucuroide effectively and could slow down the absorption of sugar in intestinal tract. DNJ has important role in regulate blood sugar level, antiviral and inhibiting metastasis. It have been used in diabetes mellitus treatment and showed high pharmacodynamic effect and medical value.. The geographic environment were complex in Heilongjiang Province, some stresses like drought, saline-alkali soil and low temperature have threated plant survival and resulted in variation in plant secondary metabolism. So, this paper aim to mulberry production status, determine method for DNJ contents in cold regions and the inductive effect between DNJ content and different environmental factors (drought, salt, shading and nitrogen stress) was reported. DNJ contents difference in diversvariety and same variety different period in Heilongjiang province were analysed. Moreover, comparative analyzed DNJ content of mulberry varieties in Heilongjiang province and typical mulberry varieties in south of Yangtze River.1. A reversed phase high performance liquid chromatography with precolumn derivatization was developed for the DNJ contents in mulberry. DNJ was extracted by0.05mmol·L-1HCL. Fluorene7-hydroxy cinnamyi chloride as the derivatization reagent and combine with DNJ form DNJ-FMOC complex compound which could identifided by ultraviolet. DNJ contents were detected by High Performance Liquid Chromatography.2. DNJ contents in local varieties were the highest in north mulberry, average DNJ content in Tailai leaf up to4.2mg·g-1and is three times higher than other varieties (mean1.4mg·g-1). DNJ contents of leaf grow in upper was higher than middle and down leafs. In the progress of DNJ accumulative, samples picked in July to August were higher than others. Mulberry DNJ contents in Heilongjiang province were higher significantly than south varieties3. The studies found that changed environmental factors could induce leaf DNJ content changing. The results showed that leaf DNJ contents were increased by mild stress, but these were decreased in severe stress. The stem length, number of blades, stem biomass and total biomass were reduced. Hence, secondary metabolism abundances could be increased by suitable external environment stimulate, but superior content couldnot be obtain under extreme ambient condition. These results could provide theory basis for mulberry DNJ extract and exploitation. Nitrogen is essential for alkaloids secondary metabolic and the results indicated that the DNJ contents in mulberry branches and leafs could be increased in50～150mmol·L and the way of hydroponic medium of nitrogen concentration. |
