Cephalotaxus harringtonia var drupacea

Powell RG, Madrigal RV, Smith CR, Mikolajczak KL. Alkaloids of Cephalotaxus harringtonia var. drupacea. 11-Hydroxycepha-lotaxine and drupacine. J. Org. Chem. 1974 39 676-680. 

Takano, I. Yasuda, M. Nishijima, Y. Hitotsuyanagi, K. Takeya, and H. Itokawa, Ester-Type Cephalotaxus Alkaloids from Cephalotaxus harringtonia var. drupacea . Phytochemistry, 1997, 44 (4), 735 - 738. 

Several new alkaloids have been isolated recently from Cephalotaxus harringtonia var. drupacea, two of which, harringtonine (Va) and iso-harringtonine (Vb), show inhibitory activity against L 1210 and P388 at dose levels of 0-25 to 4 mg/kg and 0-75 to 12 mg/kg respectively [43, 44]. The structure of the heterocyclic portion of these molecules has been established [45] by spectroscopic and x-ray crystallographic studies on cephalotaxine and its methiodide, and the terpenoid portion by spectroscopic analysis of... 

Oppenauer oxidation gave the hemiketal (16). Furthermore, hydrolysis of the diacetate (14 R = R = Ac) in aqueous dioxan at ambient temperatures resulted in epimerization at C-11. All these reactions are best accommodated by the proposed stereochemical formulation (14 R = R = H) for 11-hydroxy-cephalotaxine. Interestingly, this formulation represents the most hindered of four possible geometric isomers. The alkaloids (14 R = R = H) and (15) are unique to C. harringtonia var. drupacea. It is not yet clear if drupacine (15) is identical with Alkaloid IV obtained by Asada during an extensive reinvestigation of Cephalotaxus species. ... 

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