Two new flavonoids from Bonannia graeca:: a DFT-NMR combined approach in solving structures

Two new cyclized C-geranylated flavonoids, the dihydroflavonol bonanniol C (4a) and the flavanone bonannione B (6a), were isolated as minor compounds from the aerial parts of Bonannia graeca (Umbelliferae). Their structures were elucidated by a combined approach of extensive spectroscopic means and quantum mechanical methods. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007).