Vavříková Eva, Gavezzotti Paolo, Purchartová Kateřina, Fuksová Kateřina, Biedermann David, Kuzma Marek, Riva Sergio, Křen Vladimír
Laboratory of Biotransformation, Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídeňská 1083, CZ 142 20 Prague, Czech Republic.
Istituto di Chimica del Riconoscimento Molecolare, Consiglio Nazionale delle Ricerche, Via Mario Bianco 9, I 20131 Milano, Italy.
Int J Mol Sci. 2015 May 26;16(6):11983-95. doi: 10.3390/ijms160611983.
A panel of lipases was screened for the selective acetylation and alcoholysis of silychristin and silychristin peracetate, respectively. Acetylation at primary alcoholic group (C-22) of silychristin was accomplished by lipase PS (Pseudomonas cepacia) immobilized on diatomite using vinyl acetate as an acetyl donor, whereas selective deacetylation of 22-O-acetyl silychristin was accomplished by Novozym 435 in methyl tert-butyl ether/ n-butanol. Both of these reactions occurred without diastereomeric discrimination of silychristin A and B. Both of these enzymes were found to be capable to regioselective deacetylation of hexaacetyl silychristin to afford penta-, tetra- and tri-acetyl derivatives, which could be obtained as pure synthons for further selective modifications of the parent molecule.
筛选了一组脂肪酶，分别用于水飞蓟亭和全乙酰水飞蓟亭的选择性乙酰化和醇解反应。固定在硅藻土上的洋葱假单胞菌脂肪酶PS（Pseudomonas cepacia）以乙酸乙烯酯作为乙酰供体，实现了水飞蓟亭伯醇基团（C-22）的乙酰化，而诺维信435在甲基叔丁基醚/正丁醇中实现了22-O-乙酰基水飞蓟亭的选择性脱乙酰化。这两个反应均未对水飞蓟亭A和B进行非对映体区分。发现这两种酶都能够对六乙酰水飞蓟亭进行区域选择性脱乙酰化，得到五乙酰、四乙酰和三乙酰衍生物，这些衍生物可作为纯合成子用于母体分子的进一步选择性修饰。
