本論文研究“酮（tropolone）”在秋水仙素與甲硫秋水仙素的光化學及其在凝相中光物理的性質。秋水仙素〈1〉於甲醇中照光得到β－lumicolchicine〈2〉、γ－lumicolchicine〈3〉，將β－lumicolchicine〈2〉繼續照光，可以得到α－lumicolchicine〈4〉。甲硫秋水仙素〈5〉於甲醇中照光得到β－lumithiocolchicine〈6〉、γ－lumithiocolchicine〈7〉。
秋水仙素〈1〉與甲硫秋水仙素〈5〉二者光物理性質，由吸收與放射光譜，不管在位置、生命期或是結構上皆顯示最低激發單態為屬於（π、π*）的能量躍遷。
由量子效應以同一化合物〈1〉或化合物〈5〉在不同極性溶劑的比較，以及化合物〈1〉、化合物〈5〉分別以同一溶劑之量子效應的比較：
Ⅰ、化合物〈1〉光化學量子產率：ψ甲醇中≒ψ苯中；
（ψ〈1〉甲醇中＝1.25×10-6，ψ〈1〉苯中＝1.15×10-6）。
Ⅱ、化合物〈5〉光化學量子產率：ψ甲醇中＜＜ψ苯中；
（ψ〈5〉甲醇中＝4.90×10-9，ψ〈5〉苯中＝6.66×10-8）。
Ⅲ、化合物〈1〉之β/γ＞化合物〈5〉之β/γ；
（苯中：β/γ〈1〉＝6.5，β/γ〈5〉＝2.1）
（甲醇中：β/γ〈1〉＝13，β/γ〈5〉＝2.2）。
由Ⅰ、Ⅲ結果推測化合物〈1〉進行不受溶劑極性影響而對立體選擇性大的Woodward－Hoffmann 的電環反應；由Ⅱ、Ⅲ結果推測由於化合物〈5〉中（－SCH3）的效應，使得進行易受溶劑極性影響而對立體選擇性較小的電荷分離環合反應。
綜合上述推測，得知秋水仙素〈1〉光化學反應機制直接由單態激發態（π，π*）直接進行酮環上Woodward－Hoffmann 的電環協同反應（concerted reaction）。甲硫秋水仙素〈5〉光化學反應機制則由單態激發態能階（π，π*）經電荷轉移至電荷分離能階導致酮環上電荷分離環合反應。

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.

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、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、R.Grewe, and W.Wulf, “Rudolf Grewe and Wilhelm Wulf:Die Umwandlung des Colchicines durch Sonnenlicht”, Chem.Ber.,1951,Vol.84,pp621-625。
4、E.J.Forbes.,“Colchicine and Related Compounds. Part ⅩⅣ.Structure of β-andγ-Lumicolchicine.” ,J.Chem.Soc. , 1955,pp3865-3870。
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。
6、O.L.Chapman, H. G. Smith and R. W. King ,“The Structure ofβ- Lumicolchicine.”, J. Am. Chem. Soc., 1963,Vol.85,pp803-806。
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。
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。
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。
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。
11、Jae Chol Lee and Jin Kun Cha ,“Total Synthesis of(-)-Colchicine by an Oxyallyl[4+3]Cycloaddition” ,Tetrahedron , 2000, Vol. 56 , pp10175-10184。
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。
13、P.Dustin, Jr. ,“New Aspects of the Pharmacology of Antimitotic Agents” ,Pharmacol. Rev. , 1963,Vol.15 ,pp449~480。
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）。
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）。
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。