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1985 (1)
1Author    G. Fürstenberger, E. H. EckerRequires cookie*
 Title    On the Active Principles of the Spurge Family (Euphorbiaceae) XI. [1] The Skin Irritant and Tumor Promoting Diterpene Esters of Euphorbia tirucalli L. Originating from South Africa  
 Abstract    The irritant and tum or-prom oting constituents o f latex of Euphorbia tirucalli L. originating from South Africa were isolated. They were identified as irritant ingenane and tigliane type diterpene esters derived from unsaturated aliphatic acids and acetic acid and the polyfunctional diterpene parent alcohols 4-deoxyphorbol, phorbol and ingenol, respectively. The irritant and tum or-prom oting esters of 4-deoxyphorbol are predominant and were fully characterized chem ically and biologically. They are positionally isomeric 12,13-acylates, acetates e.g. Euphorbiafactors T i,—Ti4. A s acyl groups they carry hom ologous, highly unsaturated alipha­ tic acids o f the general structure C H 3 — (C H 2)m — (CH = CH)" — CO O H (m = 2,4; « = 1,2, 3,4,5; N = 2n + m + 2). C orresponding diesters o f 4-deoxy-4a-phorbol are also present which are biologi­ cally inactive. Com parison o f structures and biological activities o f 12,13-diesters o f 4-deoxyphor-bol indicates that — for a distinct total number o f C-atoms (N) in the acyl m oiety — an increasing number of conjugated double bonds (n) may increase the irritant but decrease the tum or-prom ot­ ing activity. R eplacem ent o f the hydroxyl function at C-4 (phorbol-12,13-diesters) by hydrogen (corresponding 4-deoxyphorbol-12,13-diesters) does not essentially alter biological activities. Epim erization o f 4-deoxyphorbol-12,13-diesters at C-4 abolishes biological activities. The specific chem ical properties dem onstrated for the diterpene ester irritants contained in the latex o f E. tirucalli and hence in all plant parts may be useful in trials to abolish the potential risk of cancer involved especially in occupational mass production and handling o f the plant. Som e of the structure activity relations o f the Euphorbia factors isolated made them excellent tools in experim ental cancer research for the analysis o f mechanisms of tum origenesis. 
  Reference    Z. Naturforsch. 40c, 631—646 (1985); received April 19 1985 
  Published    1985 
  Keywords    Skin Irritation, 4-D eoxyph orb ol, Cocarcinogenesis, Tumor Promoters, Occupational Cancer 
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 TEI-XML for    default:Reihe_C/40/ZNC-1985-40c-0631.pdf 
 Identifier    ZNC-1985-40c-0631 
 Volume    40