Study On The Natural Coumarins From Citrus And Its Related Genera

Citrus and its related generas are well known not only for rich genetic diversity, but aslo for various nutritional and healthy functions. Recently, studies on functional ingredients in Citrus become an active area. Coumarins belonging to aromatic substances have a large range of bioactive functions, making them have wide application and remarkable market prospects.In this study,67typical samples belonging to Citrus (66) and its related genera (1) were used to quantitatively determined coumarins.The main results were as follows:(1)The distribution of coumarins in different organsSeventy-six types of coumarins were detected in roots from67collected samples, of which more than20did not be reported before. Based on the data from different organs of Meyer Lemen (C.limonia Osbeck) grafted on poncitus trifoliata, the relative content of coumarins in root is the highest(up to11.09%). Among different types of samples used in this study, the average relative content in roots also obviously varied, C. aurantifolia showing highest value (15.10%), followed by P. trifoliata (14.87%) and C.junos(5.21%)..(2)The coumarin biosynthesis impacted by Inter-and external factors.Lots of the internal and external factors such as graft, age, soil types, growth seasons, can affect the components as well as the relative contents of coumarin in Citrus and its related genera. Through analyzing the P. trifoliate roots with different age, the results showed that the total relative contents and the components of coumarins were both higher in perennial roots than in annual, the same case to C. junons. Analyzing the total relative contents in roots and the spring shoot leaves of C. sinensis X P. trifoliata cultivated in different types soil showed that the soil types could affect the coumarin biosynthesis in Citrus plant, and the value in the red soil was higher than that in the sandy. Additionally, The relative contents and the compositions of coumarins varied considerately among citrus species, among cultivars within the same species, among different organs of the same cultivar or at different growing seasons. Daidai (C. aurantium), C.ichangensis, Guanxian4(C. ichangensis) obtained the highest levels of the relative contents and the compositions at anthesis and fruitlet stage. While, the relative contents gradually decreased with fruit maturing.(3) The fingerprint of12samples based on coumarin components and unique components analysis.Twenty-three coumarin components identified from the spring, the summer and the autumn shoot leaves were selected out to fingerprint12samples.The results showed that these23coumarin components could completely distinguish the12samples. Among76coumarin components identified in this study,29were unique components,i.e. only contained by one sample. Seven of them existed in C. limon, showing richest unique coumarin components. C.grandis, C.reticulata, C. paradis and P. trifoliata also had unique coumarin components, respectively. However, the coumarins were not detected in the flesh of’Hamlin’(C.sinensis) and the autumn shoot of’Luofu’(F.margarita). All this could help us indentify citrus cultivars.