PHENYLPHENALENONIC PHYTOANTICIPINS - NEW ACENAPHTYLENE AND DIMERIC PHENYLPHENALENONES FROM THE RESISTANT MUSA SELECTED HYBRID SH-3481

A new acenaphtylene derivative and two new dimeric phenylphenalenones has been isolated from healthy rhizomes of Musa selected hybrid resist ant cultivar SH-3481. The structures of the new substances were elucid ated using spectroscopy data. The chemical shift for all the hydrogen and carbon atoms in the substances were unambiguously established by m ono and bi-dimensional, homo and heteronuclear NMR experiments. Seven previously reported phenylphenalenone type phytoalexins were also now isolated as constitutive natural antibiotics and so as phytoanticipins from this resistant banana cultivar, suggesting that this type of phy toalexins play an important role as part of the resistance mechanisms to fungal diseases in this important alimentary resource botany family . (C) 1997 Elsevier Science Ltd.