title: Lipases in green chemistry: acylation and alcoholysis on steroids and nucleosides.
abstract: In this article, we describe the application of lipases in acylation and alcoholysis reactions on steroids and nucleosides. In the field of steroids, a variety of acetyl and fatty acid derivatives of androstanes, pregnanes, and cholestanes have been prepared through lipase-catalyzed acylation and alcoholysis reactions taking advantage of the high regio- and stereoselectivity of these enzymes. The substrates as well as the products show a high degree of biological activity as neurosteroids, hormones, and glucocorticoids. The regioselective preparation of diacylated nucleosides by means of an enzymatic alcoholysis allowed the synthesis of nucleosides prodrugs or modified nucleosides. The quantitative full deacylation and dealkoxycarbonylation of nucleosides and steroids is a mild synthetic method for the deprotection of these labile compounds. Some of the reported steroid and nucleoside products are novel, and it is not possible to obtain them satisfactorily by following traditional synthetic procedures. The advantages presented by this methodology, such as selectivity, mild reaction conditions, and low environmental impact, make the lipases an important tool in the application of the principles of Green Chemistry, offering a convenient way to prepare derivatives of natural compounds with a great potential in the pharmaceutical industry.
authors.affiliation: Laboratorio de Biocatálisis, Departamento de Química Orgánica y UMYMFOR, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina. alib@qo.fcen.uba.ar
authors.forename: Alicia
authors.initials: A
authors.lastname: Baldessari
authors.forename: Luis E
authors.initials: LE
authors.lastname: Iglesias
mesh_terms: D000215:Acylation; D000731:Androstanes / Q000138:chemical synthesis; D055162:Biocatalysis; D001688:Biological Products / Q000138:chemical synthesis*; D002175:Candida / Q000737:chemistry; D002776:Cholestanes / Q000138:chemical synthesis; D005227:Fatty Acids / Q000737:chemistry; D005656:Fungal Proteins / Q000737:chemistry*; D055772:Green Chemistry Technology; D008049:Lipase / Q000737:chemistry*; D009705:Nucleosides / Q000737:chemistry*; D011278:Pregnanes / Q000138:chemical synthesis; D011355:Prodrugs / Q000138:chemical synthesis; D013237:Stereoisomerism
chemical_list: D000731:Androstanes; D001688:Biological Products; D002776:Cholestanes; D005227:Fatty Acids; D005656:Fungal Proteins; D009705:Nucleosides; D011278:Pregnanes; D011355:Prodrugs; D008049:Lipase; C431349:lipase B, Candida antarctica