Seasonal changes of metabolites in phloem sap from Broussonetia papyrifera

Gas chromatography-Mass spectrometry (GC-MS) were employed to analyze the whole metabolites in phloem sap of Broussonetia papyrifera and the seasonal changes of content of these metabolites were also investigated. Thirty-eight metabolites were detected in BP phloem exudates. The highest content (44.59mg g-1) of total metabolites was presented in March. High contents of organic acids and sugars were detected in BP phloem exudates from all growing months. Smaller amounts of fatty acids and alcohols were also detected in BP phloem exudates. Interestingly, some metabolites, such as PI3 kinase inhibitor, Chlorogenic acid, Chelerythrine and palmitic acid, which have properties of bioactivity to anticancer and anti-inflammation, were also detected. Quininic acid was the most abundant organic acid, representing up to 86.3% (average value) of all organic acids. D-fructose, D-glucose, and sucrose were the major soluble sugars in phloem saps and the maximum of sugars content was 19.76mg g-1 (average value) in November. Seasonal changes of contents of metabolites were different among individuals. The metabolites analysis double confirmed that the BP phloem sap can be serviced as an important resource for synthesis of pharmaceutical and human health products.