Anti-inflammatory and antioxidant jasmonates and flavonoids from lychee seeds

Lychee (Litchi chinensis Sonn.) is a famous tropical fruit. While enjoying its delicacy, it also produces a lot of lychee seeds as waste. In this study, bioactive phytochemical study of the seeds of lychee led to the isolation and identification of four methyl jasmonate analogs (1-4), one lignanoside (5), together with fifteen flavonoids (6-20). Their chemical structures were established on the basis of spectroscopic analysis including HR-ESI-MS, 1D and 2D NMR spectra. The anti-inflammatory and antioxidant activities were evaluated for the isolated compounds. Compounds 2 and 3 exhibited notable inhibition on NO production induced by lipopolysaccharides (LPS) in macrophages cell line RAW 264.7. Compound 5 and some flavonoids revealed potent antioxidant capacities. The results disclosed that the methyl jasmonates in lychee seeds may be partially responsible for anti-inflammatory activity of lychee and could be served as anti-inflammatory agent in functional food.