Sorbifolivaltrates A-D, diene valepotriates from Valeriana sorbifolial

Four new diene valepotriates, sorbifolivaltrates A-D (1-4), and the known compounds isovaltrate (5), valtrate (6), seneciovaltrate (7), valtrate hydrine B3 (8), and valtrate hydrine B7 (9), have been isolated by bioassay-guided fractionation of the cytotoxic hexanes and methyl ethyl ketone crude extracts of the aerial parts of Valeriana sorbifolia occurring in the Sonoran desert. The structures of 1-4 were determined on the basis of their high-resolution mass spectrometric and NMR spectroscopic data. All compounds exhibited weak to moderate cytotoxicity against the human metastatic prostate cancer cell line, PC-3M.