A Study Of The Bioactive Constituents From The Leaves Of Juglans Regia (â… )

Two flavonoides were isolated from the dried leaves of Juglans regia. Their chemical structures were elucidated as kaempferol(I), kaempferol-3-0-arafuranoside (II), respectively, by means of spctroscopic analysis(1 HMMR,13CMMR, IR, UV, EI-MS, FAB-MS, HSQC), chemical reaction, and by companon of the spectral data of the known compounds. It was found that ethylacetate extract significantly inhibited lettuce seed germination, root and seedling growth at concentration 111(0.019g-ml-1), indicating that that ethylacetate part had potent allelopathy. Compound II promoted the lettuce growth at low concentration (200 g-ml-1)and inhibited the growth at high concentration (800 g-mT-1). Compound II showed excellent fungicidal activities against Bacillus subtilis at the dosage of 100 g-ml-1, weak effect against Staphylococcus auraeus , Trichodermin. E.coli at the dosage of 100 g-ml-1, 200 g-ml-1, 400 g-ml-1, and inactive to Penicillium sp and Aspergillus sp. Thirteen compounds from petroleumether extract were identified by GC-MS, and the content amounts to 73.486% in total. Juglone has been considered to be the major allelochemical ofjuglans plants in the past years, but our studies firstly show that flavonoides are important allelochemicals in the leaves ofjuglans regia. This will offer new evidence for exploiting environment-friendly herbicides.