8’,9’-Bis-nor-neolignans from Cedrela odorata and their antiangiogenic activity

Two previously undescribed 8',9'-bis-nor-neolignans, 9-acetyltoonin C (1) and threo-guaiacylglycerol-beta-methyl vanillate ether (2), were isolated from the stem bark of Cedrela odorata (Meliaceae), together with 4,5-dihydroblumenol A, 2-(3,4-dimethoxyphenyl)ethyl-beta-d-glucopyranoside, scopoletin, homovanillic alcohol, and 7-megastigmene-3,6,9-triol. All compounds were characterized by 1D and 2D NMR and HRESIMS data. The new compounds and other lignans obtained from our chemical library, namely erythro-4,7,9,9'-tetrahydroxy-3,3'-dimethoxy-8-O-4'-oxyneolignan (3), urolignoside (4), secoisolariciresinol 9-O-beta-D-glucopyranoside (5), icariside E-3, and erythro-4,7,9,9'-tetrahydroxy-3,3'-dimethoxy-8-O-4'-oxyneolignan-9'-O-beta-D-glucopyranoside, were then evaluated for their antiangiogenic activity by the in vivo zebrafish embryos test. Compounds 1, 2, and 3 exhibited the best antiangiogenic response, while 4 and 5 showed mild inhibitory effects on EAP release after treatment of zebrafish embryos. In particular, compound 2 induced an inhibition of 42.56 % at 10 mu M, similarly to 2-methoxyestradiol used as reference compound.