Lipase B from Candida anturctica has been shown to be an efficient catalyst for the regioselective acylation of the dammarane type glucoside ginsenoside Rg1 (1) on reaction with vinyl acetate in t-AmOH, affording the corresponding 6’-O-acetyl derivative lb in high yield. The structure of lb was determined through a careful inspection of its lH NMR at 600 MHz, which allowed for the complete assignment of the signals of the sugar’s protons. The introduction of a carboxyacetyl residue was then investigated using different protocols. The best results were obtained with a two-step sequence involving the preliminary enzymatic acylation of 1 with bis(2,2,2-trichloroethyl) malonate to give the mixed malonyl derivative lf, followed by selective chemical hydrolysis with ZdAcOH to the 6’-O-carboxyacetyl ginsenoside Rg1 (le).
Regioselective Enzyme-Mediated Acylation of Polyhydroxy Natural Compounds. A Remarkable, Highly Efficient Preparation of 6'-Acetyl and 6'-O-Carboxyacetyl Ginsenoside Rg1 / B. Danieli, M. Luisetti, S. Riva, A. Bertinotti, E. Ragg, L. Scaglioni, E. Bombardelli. - In: JOURNAL OF ORGANIC CHEMISTRY. - ISSN 0022-3263. - 60:12(1995 Jun 16), pp. 3637-3642.
|Titolo:||Regioselective Enzyme-Mediated Acylation of Polyhydroxy Natural Compounds. A Remarkable, Highly Efficient Preparation of 6'-Acetyl and 6'-O-Carboxyacetyl Ginsenoside Rg1|
|Parole Chiave:||ginsenoside ; lipase B ; Candida antarctica ; regio-selective acylation|
|Settore Scientifico Disciplinare:||Settore CHIM/06 - Chimica Organica|
|Data di pubblicazione:||16-giu-1995|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1021/jo00117a012|
|Appare nelle tipologie:||01 - Articolo su periodico|