Abstract
The thermodynamics of the inclusion reaction of flavonol, 7-methoxyflavonol and 4-phenyl-7-hydroxycoumarin (L) with /8-cyclodextrin (CD) has been studied fluorometrically with special reference to the effect of organic solvents (S). The equilibrium constants for this reaction were determined in aqueous methanol, ethanol, acetonitrile, acetone, dimethyl sulfoxide, and A’.A-dimethylformamide. The dependence of the constants on the content of the respective S was attributable to the substitution of S included in CD with L as CD ·nS+L ⇌ CD · L+nS. Also, the inclusion constants of S with CD, βn=[CD · nS][CD]-1[S]-n, were found to be linearly correlated with the solubility parameter of S for both n=1 and 2. When aqueous methanol was employed as a mobile phase, the retention behavior of coumarins on a reversed-phase HPLC column was studied in the presence of j8-CD as a mobile-phase component. The change in the capacity factors could be reasonably explained by the same inclusion scheme as that mentioned above.
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References and Notes
M. L. Bender and M. Komiyama, “Cyclodextrin Chemistry”, Springer-Verlag, Berlin, 1978.
W. Saenger, Angew. Chem. Int. Ed. Engl, 19, 344 (1980).
F. Toda and A. Ueno (ed.), “Shikurodekisutorin (Cyclodextrins, in Japanese)”, Sangyoutosho, Tokyo, 1995.
H. G. Barth, W. E. Barber, C. H. Lochmuller, R. E. Majors and F. E. Regnier, Anal. Chem., 60, 387R (1988) and papers cited therein.
J. G. Dorsey, J. P. Foley, W. T. Cooper, R. A. Barford and H. G. Barth, Anal. Chem., 62, 324R (1990) and papers cited therein.
J. G. Dorsey, J. P. Foley, W. T. Cooper, R. A. Barford and H. G. Barth, Anal. Chem., 64, 353R (1992) and papers cited therein.
J. G. Dorsey, W. T. Cooper, J. F. Wheeler, H. G. Barth and J. P. Foley, Anal. Chem., 66, 500R (1994) and papers cited therein.
J. G. Dorsey, W. T. Cooper, B. A. Siles, J. P. Foley and H. G. Barth, Anal. Chem., 68, 515R (1996) and papers cited therein.
A. Murata, T. Omae and T. Suzuki, Bunseki Kagaku, 29, 780 (1980).
A. Murata, N. Sugiyama and T. Suzuki, Bunseki Kagaku, 30, 204 (1981).
T. Ito, O. Suzuki, T. Suzuki and A. Murata, Analyst [London], 111, 423 (1986).
A. Murata, N. Sugiyama and T. Suzuki, Bunseki Kagaku, 36, 27 (1987).
T. Ito, H. Oomura, T. Suzuki and A. Murata, Bunseki Kagaku, 37, 327 (1988).
T. Nagata, S. Nishimori, H. Kimura, T. Ito and A. Murata, Bunseki Kagaku, 38, 473 (1989).
H. Yoshida, T. Ito and A. Murata, Fresenius’ J. Anal. Chem., 338, 738 (1990).
S. Yamada, K. Maejima and A. Murata, Bunseki Kagaku, 40, 455 (1991).
S. Yamada, K. Ban and A. Murata, Bunseki Kagaku, 40, 337 (1991).
S. Yamada, H. Mori, M. Nakamura and S. Nakamura, Bunseki Kagaku, 44, 67 (1995).
S. Yamada, N. Achiwa, M. Nakamura and S. Nakamura, Bunseki Kagaku, 45, 265 (1996).
S. Yamada, K. Shibata and A. Murata, Anal. Sci., 9, 467 (1993).
A. J. Sophianopoulos, Anal. Chem., 64, 2652 (1992).
Although some water molecules have been found to be included in the cavity of j8-CD in water [see, for example, T. Steiner and G. Koellner, J. Am. Chem. Soc., 116, 5122 (1994)], in Eq. (3) nothing will be referred to the number of H20 included in j8-CD.
Thermodynamically, [S] in Eq. (4) should be replaced by the activity of S in binary solvent mixtures. However, as the purpose of the present work is to examine how the change in capacity factors is affected by the inclusion of each probe with j8-CD in eluent and this change is usually correlated with the volume fraction of an organic modifier in eluent, molar concentration will be used as the unit for the amount of S from a practical point of view.
J. H. Hildebrand and R. J. Scott, “Regular Solutions”, Prentice-Hall, Englewood Cliffs, 1962.
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Yamada, S., Murabayashi, K. & Nakamura, M. Inclusion Reaction of Some Fluorophores with β-Cyclodextrin and Its Effect on Their Reversed-Phase HPLC Retention. ANAL. SCI. 14, 897–901 (1998). https://doi.org/10.2116/analsci.14.897
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DOI: https://doi.org/10.2116/analsci.14.897