Ingenane diterpenes

Several studies have examined the chemistry of Euphorbia species. A majority of these investigations have focused on the chemical character of the plant latex relative to taxonomy (, ) or mammalian toxicity Toxic Ingenane diterpenes (phorbols) have also been... 

In the laboratory of J.H. Rigby, synthetic studies were undertaken on the ingenane diterpenes. During these studies, it was necessary to investigate the ring opening reactions of a structurally complex allylic epoxide intermediate. This allylic epoxide was prepared from a 1,3-diene in three steps dihydroxylation, epoxidation and Corey-Winter olefination. 

Rigby, J. H., Bazin, B., Meyer, J. H., Mohammadi, E. Synthetic Studies on the Ingenane Diterpenes. An Improved Entry into a trans-Intrabridgehead System. Org. Lett. 2002,4, 799-801. 

Evans, F. J. and C, J. Soper, The tigliane, daphnane, and ingenane diterpenes. Their chemistry, distribution, and biological activities, Lloydia, 41, 193-233 (1978). 

Evans, F.J., and C.J. Soper The tigliane, daphnane and ingenane diterpenes, their chemistry, distribution and biological activities. A review. Lloydia 41, 193 (1978). 

Gotta H, Adolf W, Opferkuch HJ, Hecker E. (1984) On the active principles of the Enphorbiaceae, IX. Ingenane type diterpene esters from five Euphorbia species. Z Naturforsch B 39 683-694 Hohmann J, Evanics E, Berta L, Bartok T. (2000) Diterpenoids from Euphorbia peplus. Planta Med 66 291-294 Ivanova A, Khozin-Goldberg 1, Kamenarska Z, Nechev J, Cohen Z, Popov S, Stefanov K. (2003) Lipophylic componnds from Euphorbia peplis L. — a halophytic plant from the Bnlgarian black sea coast. Z. Naturforsch 58c 783-788. 

A liquid chromatography-tandem mass spectrometry (LC-MS-MS) method was developed to detect tumor-promoting diterpene esters of the tigliane and ingenane types within plant extracts. Fractionation on a Cig HPLC column was followed by MS-MS-multiple reaction monitoring (MRM). 

Plants of the Euphorbiaceae family and particularly members of the Euphorbia genus have long been known to yield latexes with irritant and carcinogenic properties and these properties have been associated with diter-penes of the phorbol class. Members of the Euphorbia genus also contain diterpenes with other skeletons, among them the ingenane derivative PEP005 (38). " ... 

C2oH2 Os, Mr 348.44, an amorphous, tetracyclic, unsaturated diterpene with one keto and four hydroxy groups, derived from ingenane (see Euphorhiaceae and Thymelaeaceae poisons). 

Many plants of the Euphorbiaceae and Thymelaeaceae have long been known to be intensely irritating to the skin. Some produce severe skin lesions in humans and in livestock (Evans and Schmidt, 1980). Members of the genus Euphorbia are especially well known for their irritant and poisonous properties. Polyfunctional diterpene esters of the tigliane, ingenane, and daphnene types are responsible for the acrid... 

The major stmctural types known are the phorbol esters [e.g., a tigliane from Sapium japonicum (17)] Croton, Sap-ium, Aleurites, Mancinella, Baliospermum, and Euphorbia), ingenol esters [e.g., ingenane (18)] Euphorbia), and daph-nanes [e.g., daphnetoxin (19)] Euphorbia, Hura, Hip-pomane, Excoecaria, Baliospermum, Thymelaeaceae) (Fig. 22.7) most of the plants that contain these diterpenes are in subfamilies Crotonoideae and Euphorbioideae (Kinghom, 1979 Webster, 1975). 

---