Advances in the Biosynthesis of Pyranocoumarins: Isolation and <sup>13</sup>C-Incorporation Analysis by High-Performance Liquid Chromatography–Ultraviolet–Solid-Phase Extraction–Nuclear Magnetic Resonance Data
Jéssica Cristina Amaral, Michelli M. Silva, Michelli M. da Silva, M. Fátima G. F. da Silva, M. Fátima G. F. da Silva, Thayana C. Alves, Antônio G. Ferreira, Moacir Rossi Forim, João Batista Fernandes, Edieidia S. Pina, Adriana A. Lopes, Ana Maria Soares Pereira, Valdenice Moreira Novelli
Abstract
Citrus sinensis and Citrus limonia were obtained by germination from seeds, and isotopic-labeling experiments using d -[1- 13 C]glucose were performed with the seedlings. After 60 days, the seedlings were analyzed by high-performance liquid chromatography–ultraviolet–solid-phase extraction–nuclear magnetic resonance, data and the 13 C enrichment patterns of xanthyletin and seselin indicated that the pyran ring was formed by the methylerythritol phosphate pathway and that the coumarin moiety was derived from the shikimate pathway in both compounds. This information regarding the biosynthetic pathway can be used to increase resistance against phytopathogens, because xanthyletin and seselin are reported to have antimicrobial activity on the growth of Xylella fastidiosa, which causes citrus variegated chlorosis in orange.