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1Author    Bernd Sorg, Michael Gschwendt, HeinzWalter Thielmann, Erich HeckerRequires cookie*
 Title    Struktur-Wirkungsbeziehungen polyfunktioneller Diterpene des Tigliantyps, IV [1-3] Structure-Activity Relationships of Polyfunctional Diterpenes of the Tigliane Type, IV [1-3] Derivatives of Tigliane without or with Opened Cyclopropane Ring and their Irritant and Promoting Activity  
 Abstract    Derivate des Tiglians mit fehlendem oder geöffnetem Cyclopropanring und ihre irritierende und tumorpromovierende Wirkung The synthesis of the esters 6d-8d, 9 c and 10 c is described. These compounds are closely structurally related to the irritant and tumorpromoting 12-0-tetradecanoylphorbol-13-acetate (TPA, 2 a) and to phorbol-12,13-didecanoate (PDD, 2 c) except that they possess no cyclopropane ring. Biological tests show that opening or complete removal of the cyclopropane ring leads to nearly total loss of irritant or tumorpromoting (tested in the case of 9 c and 10 c) activity. 
  Reference    Z. Naturforsch. 35b, 1470—1475 (1980); eingegangen am 2. Juni 1980 
  Published    1980 
  Keywords    Cocarcinogens, Phorbol, Structure-activity-relationship, Tumor Promoter, Irritants 
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 TEI-XML for    default:Reihe_B/35/ZNB-1980-35b-1470.pdf 
 Identifier    ZNB-1980-35b-1470 
 Volume    35 
2Author    H. J. Opferkuch, W. Adolf, B. Sorg, S. Kusumoto+, E. HeckerRequires cookie*
 Title    Zur Chemie des Ingenols, I Ingenol und einige seiner Derivate On the Chemistry of Ingenol, I Ingenol and Some of its Derivatives  
 Abstract    The tetracyclic polyfunctional diterpene ingenol (1) is the prototype of many di-terpenoid parent alcohols of the ingenane type. Esters of these parent alcohols occur -partly together with esters of polyfunctional diterpene parent alcohols of the tigliane and daphnane type -as irritant, cocarcinogenic and antineoplastic principles in species of the family Euphorbiaceae (Spurge). Preparation of 1 from latex of Euphorbia ingens E.May as well as of some functional derivatives of 1 are described. 
  Reference    Z. Naturforsch. 36b, 878—887 (1981); eingegangen am 2. März 1981 
  Published    1981 
  Keywords    Cocarcinogens, Diterpene Esters, Euphorbiaceae, Tumor Promoters 
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 TEI-XML for    default:Reihe_B/36/ZNB-1981-36b-0878.pdf 
 Identifier    ZNB-1981-36b-0878 
 Volume    36 
3Author    Bernd Sorg, Erich HeckerRequires cookie*
 Title    On the Chemistry of Ingenol, III [1] Synthesis of 3-Deoxy-3-oxoingenol, Some 5-Esters and of Ethers and Acetals of Ingenol  
 Abstract    3-Deoxy-3-oxoingenol (3) was prepared from ingenol-5,20-acetonide (25) by oxidation and subsequent removal of the acetonide. 3 was acylated to give homologous 5,20-di-acylates 5-9. From these the 5-monoacylates 14, 15 and 17 were obtained in only moderate yields. Therefore the 20-silyl ether 10 (prepared from 3) was acylated. After smooth removal of the silyl ether the homologous 5-acylates 16. 18 and 19 resulted in good yield. The 5,20-dibutyrate 6 and all 5-acylates prepared (14-19) showed no irritant activity on the mouse ear. The 3-oxo-5-acylates 14-19 could not be reduced to give ingenol-5-acylates (24). Therefore various ingenol derivatives, 29-32, with suitable protected hydroxyl func-tions as well as the corresponding 5-clecanoates 35-38 were synthesized. The protecting groups of the derivatives 35-38 could however not be cleaved off to yield ingenol-5-decanoate (24). 
  Reference    Z. Naturforsch. 37b, 1640—1647 (1982); eingegangen am 2. Juli 1982 
  Published    1982 
  Keywords    Cocarcinogen, Diterpenes, Ingenol Esters, Tumor Promoter 
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 TEI-XML for    default:Reihe_B/37/ZNB-1982-37b-1640.pdf 
 Identifier    ZNB-1982-37b-1640 
 Volume    37 
4Author    H. Roeser, B. Sorg, E. HeckerRequires cookie*
 Title    On the Chemistry of Ingenol, Va. Preparation of Tritium-Labeled 3-O-Tetradecanoylingenol (|20-3H]-3-TI)  
 Abstract    Tritium-labeling o f the ingenol m onoester 3-O-tetradecanoylingenol (3-TI), the prototype tumor promoter o f the ingenane type diterpene esters, is described. The preparation starts with oxidation o f 3-TI by manganese dioxide to yield 3-TI-20-aldehyde which is reduced by [3H]-sodium borohydride in the presence o f equimolar amounts o f cerium trichloride hexahydrate to give [20-3H]-3-TI. The labeled promoter is obtained in 42% overall yield with a specific ra­ dioactivity o f 15.8 Ci/m mol. 
  Reference    Z. Naturforsch. 47b, 1026—1030 (1992); received December 13 1991 
  Published    1992 
  Keywords    Ingenol Ester, Tumor Promoter, Tritium-Labeling 
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 TEI-XML for    default:Reihe_B/47/ZNB-1992-47b-1026.pdf 
 Identifier    ZNB-1992-47b-1026 
 Volume    47 
5Author    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