Hecht, C, Hermann P, Friedrich J, Chang CC, Chang TC.
2005.
Thionin in a cyclodextrin nanocavity: Measuring local compressibilities by pressure tuning hole burning spectroscopy, Sep 26. Chemical Physics Letters. 413:335-341., Number 4-6
AbstractWe present pressure tuning hole burning experiments on thionin with alpha-cyclodextrin (alpha-CD) and beta-cyclodextrin (beta-CD) in a glycerol/water glass. The low temperature absorption spectra do not show the formation of a caging complex. The pressure tuning data, however, show that the compressibility of the sample with beta-CD, where the formation of an inclusion complex is not restricted due to geometrical reasons increases as compared to the other samples. This is just the opposite of what one would expect. This increase is interpreted in terms of a reduced solvent density around the chromophore due to the hydrophobic effect. (c) 2005 Elsevier B.V. All rights reserved.
Chang, TC, Yang YP, Huang KH, Chang CC, Hecht C.
2005.
Investigation of thionin-DNA interaction by satellite hole spectroscopy, May. Optics and Spectroscopy. 98:655-660., Number 5
AbstractThe interactions of the two tautomers of thionin dye with DNA have been investigated by using satellite hole burning spectroscopy. Similar features in the absorption and satellite hole spectra of thionin in the presence of calf thymus (CT) DNA and polynucleotides [d(GC)(6)](2) (GC) suggested that thionin preferentially binds to GC rather than polynucleotides [d(AT)(6)](2) (AT). Different binding effects of the two tautomers to DNA could be observed. While the imino form fully intercalates into the DNA base pairs, the amino form is only partially intercalated. In addition, a broad hole associated with an antihole appeared in the presence of DNA, particularly in GC base pairs. The coincidence of the antihole with the absorption band of the amino form showed that the amino form is the photoproduct of the imino form. An increase in intensity of the broad hole and its antihole and the loss of nonresonant hole intensity upon interaction with CT DNA could be described by rapid ground state recovery resulting from fast charge transfer between the intercalated thionin and a guanine base quenching the internal conversion. (c) 2005 Pleiades Publishing, Inc.