Minor Valepotriates from Valeriana jatamansi and Their Cytotoxicity against Metastatic Prostate Cancer Cells

Ten new valepotriates, jatamanvaltrates P–Y (1–10) and a known one, nardostachin (11), have been isolated from the whole plants of Valeriana jatamansi. The structures of the new compounds were determined by detailed spectroscopic data analysis. The isolated compounds were evaluated for cytotoxic activity against PC-3M cells, and a structure-activity relationship was examined for all the valepotriates isolated from V. jatamansi. The results highlighted the structure-activity relationship importance of the C-3–C-4 double bond, the oxirane ring, and the 10-chlorine in the valepotriates.