@article{3140859,
    title = "Enzymatic preparation of acylated derivatives of silybin in organic and
ionic liquid media and evaluation of their antitumor proliferative
activity",
    author = "Theodosiou, Eleni and Katsoura, Maria H. and Loutrari, Heleni and and Purchartova, Katerina and Kren, Vladimir and Kolisis, Fragiskos N. and and Stamatis, Haralambos",
    journal = "Biocatalysis and Biotransformation",
    year = "2009",
    volume = "27",
    number = "3",
    pages = "161-169",
    publisher = "TAYLOR & FRANCIS LTD LONDON",
    issn = "1024-2422, 1029-2446",
    doi = "10.1080/10242420902937777",
    keywords = "Silybin; lipase; ionic liquids; acylation; organic solvents; antitumor
proliferative activity",
    abstract = "Biocatalytic preparation of acylated derivatives of silybin using
several acyl donors (free fatty acids or their esters), catalyzed by
immobilized Candida antarctica lipase B, was performed in various
organic solvents as well as in imidazolium-based ionic liquids
containing either BF4- or PF6- anions. Total conversion of silybin was
achieved in acetone using short-chain acyl donors (vinyl butanoate) at a
10: 1 molar ratio of acyl donor to silybin. The enzymatic process in
ionic liquids depended strongly on the alkyl chain length of the cation
as well the anion used. Higher conversion yields (up to 75.8%) and
reaction rates (up to 0.31 mmol h(-1) g(-1) biocatalyst) were obtained
in the BF4- as compared with PF6- containing ionic liquids. The amounts
of silybin ester formed in a one-step biocatalytic process were high
(>40 g L-1) in both reaction media. The antiproliferative effect of
acylated silybin derivatives on the growth of K562 human leukemia cells
was estimated and compared with that of silybin."
}