title: Applications of counter-current chromatography in organic synthesis purification of heterocyclic derivatives of lapachol.
abstract: This work describes the application of counter-current chromatography (CCC) as a useful, fast and economic alternative for the isolation and purification of heterocyclic derivatives from lapachol and beta-lapachone, two naturally occurring compounds from Tabebuia species, and nor-beta-lapachone, a synthetic congener of lapachol. The discussed data comprise four examples of purification of synthetic reactions with different solvent systems - the mixture of the oxazole and the imidazole from beta-lapachone; the quinoxaline from nor-beta-lapachone; and the purification of the N-oxides from the quinoxaline and the phenazine from nor-beta-lapachone from their respective not fully reacted substrates by means of aqueous reversed- and normal-phase elution modes and non-aqueous solvent systems. Traditional purification of these reaction products by silica gel column chromatography demanded a large amount of solvent and time and, in some cases, serious degradation of the products occurred, leading to low yield of the reaction. High-speed counter-current chromatography (HSCCC) was used as an alternative to optimize the process and raise the yield of the reactions.
authors.affiliation: Núcleo de Pesquisas de Produtos Naturais, Universidade Federal do Rio de Janeiro, Bloco H, CCS, Rio de Janeiro, RJ, Brazil.
authors.forename: Raphael S F
authors.initials: RS
authors.lastname: Silva
authors.forename: Gilda G
authors.initials: GG
authors.lastname: Leitão
authors.forename: Thiago B
authors.initials: TB
authors.lastname: Brum
authors.forename: Ana Paula G
authors.initials: AP
authors.lastname: Lobato
authors.forename: Maria do Carmo F R
authors.initials: Mdo C
authors.lastname: Pinto
authors.forename: Antonio V
authors.initials: AV
authors.lastname: Pinto
mesh_terms: D051702:Activating Transcription Factor 6 / Q000235:genetics / Q000378:metabolism*; D002855:Chromatography, Thin Layer; D003377:Countercurrent Distribution / Q000379:methods*; D003500:Cyclization; D007093:Imidazoles / Q000737:chemistry; D015394:Molecular Structure; D009285:Naphthoquinones / Q000138:chemical synthesis / Q000737:chemistry* / Q000302:isolation & purification; D010080:Oxazoles / Q000737:chemistry; D011810:Quinoxalines / Q000737:chemistry
chemical_list: D051702:Activating Transcription Factor 6; C574724:Atf6b protein, mouse; D007093:Imidazoles; D009285:Naphthoquinones; D010080:Oxazoles; D011810:Quinoxalines; C014638:beta-lapachone; C029899:imidazole; C008252:lapachol