Biosynthesis of antimalarial lignans from Holostylis reniformis
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Data
2009-03-01
Autores
Messiano, Gisele B. [UNESP]
da Silva, Tito [UNESP]
Nascimento, Isabele Rodrigues [UNESP]
Lopes, Lucia Maria Xavier [UNESP]
Título da Revista
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Editor
Pergamon-Elsevier B.V. Ltd
Resumo
Holostylis reniformis biosynthesizes 8-8' linked lignans without 9,9'-oxygenation. To elucidate the biosynthetic pathways to these lignans, the reputed precursors [U-(14)C]phenylalanine, [9-(3)H(1)]coniferyl alcohol, and [9-(3)H(1)]isoeugenol were administered to roots of the plant, which led to the incorporation of (3)H and (14)C into ten 2,7' linked-lignans (aryltetralone lignans) and two 7,7'-epoxylignans (furan lignans). These administration experiments demonstrated that the lignans were propenylphenol-derived and that H. reniformis can exhibit regioselective control over radical-radical coupling (via isoeugenol radicals). Regiospecific control over propenylphenol-derived lignan biosynthesis was observed, together with diastereoselective control of C2-C7' bond formation for the aryltetralone lignans (7'R). These experiments provide evidence that isoeugenol is a biosynthetic intermediate to the aryltetralone and furan lignans. (C) 2009 Elsevier Ltd. All rights reserved.
Descrição
Palavras-chave
Holostylis reniformis, Aristolochiaceae, Lignans, Neolignans, Aryltetralone lignans, Epoxylignans, Biosynthesis, Propenylphenols
Como citar
Phytochemistry. Oxford: Pergamon-Elsevier B.V. Ltd, v. 70, n. 5, p. 590-596, 2009.