18635-24-0Relevant articles and documents
Biomimetic in vitro oxidation of lapachol: A model to predict and analyse the in vivo phase i metabolism of bioactive compounds
Niehues, Michael,Barros, Valeria Priscila,Emery, Flavio Da Silva,Dias-Baruffi, Marcelo,Assis, Marilda Das Dores,Lopes, Norberto Peporine
experimental part, p. 804 - 812 (2012/09/10)
The bioactive naphtoquinone lapachol was studied in vitro by a biomimetic model with Jacobsen catalyst (manganese(III) salen) and iodosylbenzene as oxidizing agent. Eleven oxidation derivatives were thus identified and two competitive oxidation pathways postulated. Similar to Mn(III) porphyrins, Jacobsen catalyst mainly induced the formation of para-naphtoquinone derivatives of lapachol, but also of two ortho-derivatives. The oxidation products were used to develop a GC-MS (SIM mode) method for the identification of potential phase I metabolites in vivo. Plasma analysis of Wistar rats orally administered with lapachol revealed two metabolites, α-lapachone and dehydro-α-lapachone. Hence, the biomimetic model with a manganese salen complex has evidenced its use as a valuable tool to predict and elucidate the in vivo phase I metabolism of lapachol and possibly also of other bioactive natural compounds.
Conversion of lapachol to array of furano and pyranonaphthoquinone congeners
Krishna, Vivek,Lamba, Jyoti,Singh, Pahup
, p. 1039 - 1044 (2007/10/03)
Chemical conversion of lapachol to α-lapachone, β-lapachone, dehydro-α-lapachone, dehydroiso-α-lapachone and dehydroiso-β- lapachone by reaction with aqueous NaNO2 and glacial AcOH; rhinacanthin-A, stenocarpoquinone-A, stenocarpoquinone-B and its isomer by reaction with meta-chloroperbenzoic acid at 0° for 30 min and dehydro-α-lapachone and dehydro-β-lapachone at 25° for 4 h respectively and di- and tribromo derivatives by reaction with Br2 in chloroform has been reviewed. In most of these reactions prenyl chain cyclises into an oxygen function to give a number of furano and pyrano-naphthoquinone derivatives. Some of these naphthoquinones co-occur with lapachol in the same plant species.
