UHPLC-LTQ-ORBITRAP based identification and HSCCC isolation of antifungal components from Platanus SP. (Platanaceae)

Platanus is a small genus of trees belonging to Platanaceae family, mostly found to urban settings and especially in riparian or wetland regions. Platanus species, and especially Platanus orientalis (Oriental plane) are known to be severely attack by plant pathogens such as Ceratocystis fimbriata f. sp. Platani for canker stain, Apiognomonia veneta for anthracnose and Microsphaera platini for powdery mildew. However Platanus acerifolia (London plane), a hybrid between the P. occidentalis and P. orientalis, have found to be resistant to these pathogenic fungi. Therefore, this work aimed to the phytochemical screening of P. acerifolia and P. orientalis and the identification of the components potentially responsible for the resistance of P. acerifolia using a UHPLC-PDA system hyphenated to a LTQ-Orbitrap MS. Secondly, a target isolation of these components, along with the major compounds of both plant extracts were performed using a HSCCC system and various chromatographic techniques (MPLC, CC, Sephadex LH-20, prep-TLC). Two new compounds namely isobraylin and platadihydrochacone as well as five known coumarins, six flavonoids and two triterpenoids were isolated from these plant extracts. Their structure was confirmed using 1D & 2D-NMR techniques. Both plants found to be rich in coumarins, with significant quantitative alternations and seem to be responsible for the antifungal activity.