Translated Titles

The study of the photochemical and photophysical properties of moiety “tropolone” in colchicine and thiocolchicine.



Key Words

酮 ; 秋水仙素 ; 甲硫秋水仙素 ; 量子效應 ; HASH(0xbe9c9ac) ; tropolone ; colchicine ; thiocolchicine ; quantum effect ; Woodward-Hoffmann



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English Abstract

The photochemical and photophysical properties of moiety “tropolone” in colchicine〈1〉and thiocolchicine〈5〉were studied. Irradiation of colchicine〈1〉in methanol gives mainly two photoproducts:β-lumicolchicine〈2〉andγ-lumicolchicine〈3〉. Further irradiation of β-lumicolchicine〈2〉in methanol gives the photoproduct ofα-lumicolchicine〈4〉. Irradiation of thiocolchicine〈5〉in methanol gives mainly two photoproductsβ-lumithiocolchicine〈6〉andγ-lumithiocolchicine〈7〉. The low lying(π、π*) excited singlet state is responsible for the photochemistry of colchicine〈1〉and thiocolchicine 〈5〉 based on their UV-Vis absorption spectrum、fluorescence emission spectrum as well as fluorescence lifetime measurement. In comparison of the quantum effect (ψ) of compound〈1〉and compound〈5〉 in different polarity solvents, the results of the 3 aspects are obtained as follows : Ⅰ、the disappearance quantum yield of compound〈1〉:ψin methanol ≒ψin benzene. (ψ〈1〉methanol=-1.25×10-6, ψ〈1〉benzene=-1.15×10-6) Ⅱ、the disappearance quantum yield of compound〈5〉:ψin methanol <<ψin benzene. (ψ〈5〉methanol=-4.90×10-9, ψ〈5〉benzene=-6.66×10-8) Ⅲ、the quantum yield of photoadducts β/γ ratio of compound〈1〉>the quantum yield of photoadducts β/γ ratio of compound〈5〉. (in benzene:β/γ〈1〉=6.5, β/γ〈5〉=2.1) (in methanol:β/γ〈1〉=13, β/γ〈5〉=2.2) The results of Ⅰand Ⅲ show that the photochemical mechanism of colchicine〈1〉is not affected by solvent polarity but by the molecular steric selectivity. This infers that the mechanism of colchicine〈1〉 favor Woodward-Hoffmann electrocyclic reaction. The results of Ⅱand Ⅲ show that the photochemical inactivity of thiocolchicine〈5〉is dominated by solvent polarity as well as the mesomeric effect of thiomethoxy group which can stabilize the charge transfer singlet excited state. So it is inferred that the mechanism of thiocolchicine〈5〉favors the concomitant charge separation of the excited singlet state of tropolone chromophore。 In summarize, results show that the key point of the photochemical behavior of mechanism of colchicine〈1〉and thiocolchicine〈5〉favors Woodward-Hoffmann electrocyclic concerted reaction due to the N-H—O bonded of moiety, tropolone, which is ended up with the 2+2(π, π*)single excited state energy transfer. The mechanism of colchine 〈1〉 favors the (2+2) electrocyclic concerted addition, whereas that of thiocolchicine〈5〉favor the concomitant charge separation of tropolone step-wised slower cycloaddition.

Topic Category 基礎與應用科學 > 化學
理學院 > 化學系
  1. 1、Jeffrey R. Peterson1 and Timothy J. Mitchison, “Small Molecules,Big Impact:A History of Chemical Inhibitors and the Cytoskeleton”,Chemistry & Biology,2002,Vol.9,pp1275-1285。
  2. 2、A. Cohen,J.W.Cook, and (Miss)E.M.F.Roe.,“Colchicine and Related Compounds.Part I Some Observations on the Structure of Colchicine.”J.Chem.Soc.(London), 1940,pp194-197。
  3. 3、R.Grewe, and W.Wulf, “Rudolf Grewe and Wilhelm Wulf:Die Umwandlung des Colchicines durch Sonnenlicht”, Chem.Ber.,1951,Vol.84,pp621-625。
  4. 5、Pete D. Gardner, Richard L. Brandon1 and G. Rufus Haynes2, “The Structure of β-and γ- Lumicolchicine. Ring-D Elaboration Products”J. Am. Chem. Soc., 1957,Vol.79,pp6334-6337。
  5. 6、O.L.Chapman, H. G. Smith and R. W. King ,“The Structure ofβ- Lumicolchicine.”, J. Am. Chem. Soc., 1963,Vol.85,pp803-806。
  6. 7、O.L.Chapman and D. J. Pasto ,“Photochemical Transformation of Simple Troponoid Systems. I. Photo-γ-tropolone Methyl Ether”,J. Am. Chem. Soc. , 1960,Vol.82,pp3642-3648。
  7. 8、Abraham Joy, John R. Scheffer, David R. Corbin and V. Ramamurthy, “Enantioselective photoelectrocyclization within zeolites:tropolone methyl ether in chirally modified NaY”,Chem. Commun., 1998,pp1379-1380。
  8. 9、Laura Bussotti, Maurizio D’Auria, Paolo Foggi, Giordano Lesma, Roberto Righini and Alessandra Silvani,“The Photochemical Behavior of Colchicone and Thiocolchicone”,Photochemistry and Photobiology , 2000,Vol.71(1),pp29-34。
  9. 10、O.L.Chapman, H. G. Smith, “A nuclear magnetic study of keto-enol equilibria in schiff bases Ⅱ”,J. Am. Chem. Soc. , 1961,Vol.83,pp3914-3916。
  10. 11、Jae Chol Lee and Jin Kun Cha ,“Total Synthesis of(-)-Colchicine by an Oxyallyl[4+3]Cycloaddition” ,Tetrahedron , 2000, Vol. 56 , pp10175-10184。
  11. 12、G. T .Shiau, K. D. De, and R. E. Harmon, “Alkylthiocolchicines and N-Deacetyl-alkylthiocolchicine And Their Antileukemic Activity”,J. Pharm. Sci. , 1975,Vol 64 , pp646~648。
  12. 16、Ana L. P. Nery, Frank H. Quina, Paulo F. Moreira, Jr., Carlos E.R.Medeiros, Wilhelm J. Baader, Karina ,“Does the Photochemical Conversion of Colchicine into Lumicolchicines Involve Triplet Transients?A Solvent Dependence Study” ,Photochemistry and Photobiology , 2001,Vol.73(3),pp213-218。
  13. 4、E.J.Forbes.,“Colchicine and Related Compounds. Part ⅩⅣ.Structure of β-andγ-Lumicolchicine.” ,J.Chem.Soc. , 1955,pp3865-3870。
  14. 13、P.Dustin, Jr. ,“New Aspects of the Pharmacology of Antimitotic Agents” ,Pharmacol. Rev. , 1963,Vol.15 ,pp449~480。
  15. 14、葉財龍,“硫代秋水仙素衍生物的合成”, 師大化學所碩士論文(1982)。
  16. 15、溫旺盛,“秋水仙素與甲硫秋水仙素之光化學與光物理性質的研究”,師大化學所碩士論文(1990)。