Diterpenes from oriental tobacco Nicotiana tabacum 'YNOTBS1' and their bioactivities.

Seven diterpenes including two new seco-cembranoid basmanoids A () and B (), and two new labdane basmadanes A () and B (), and three known compounds (-)-dehydro-nor-ambreinolid (), (13)-8-hydroxy-13-labden-12-one (), and 14,15,16-dinor-7-oxolabda-8-ene-13-oic acid () were isolated from oriental tobacco 'YNOTBS1'. Compounds - and showed anti-tobacco mosaic virus (TMV) activity with inhibition rates in the range of 30-69% at the concentration of 1 mg/mL. However, none of them exhibited any inhibitory effects against nitric oxide (NO) production in LPS and IFN-γ-induced RAW 264.7 murine macrophages and anti-proliferative activities against cancer cell lines SMMC-7721 and A-549.