Distribución de flavanonas y flavonas en frutos de "citrus sinensis" (L) Osbeck, cv Sanguinelli

Resumen

Citrus is characterized by accumulate different phenolic compounds as flavanones and polymethoxylated flavones, which are relatively rare in other plants. The flavanones are intermediates in the biosynthesis pathway of all flavonoids, and generally are glycosylated. Depending on the species Citrus, the glycosylation may be of rutinoside type, as hesperidin in sweet orange (Citrus sinensis), or neohesperidósido as naringin in grapefruit (Citrus paradisi), or neohesperidin in sour orange (Citrus aurantium). Regarding flavones present in citrus fruits, they can be found as glycosylated forms and aglycones, the latter presenting a variety of compounds often with polysubstituted structure as hydroxyl and / or methoxyl group. Among them, scutelarein (5,6,7,4 '- tetramethoxyflavone), sinensetin (5,6,7,3', 4'-pentamethoxyflavone), tangeretin (5,6,7,8,4 '- pentamethoxyflavone) quercetogetin (3,5,6,7,3 ', 4'-hexamethoxyflavone), nobiletin (5,6,7,8,3', 4'- hexamethoxyflavonea), 3,5,6,7,8,3 ', 4'-heptametoxiflavona, and 7-hydroxy-3, 5,6,3 ', 4'-hexametoxiflavona. The degree of expression of these compounds is related with Citrus developmental stages, detecting the highest levels of flavanones and flavones as nobiletin, tangeretin sinensetin in juvenile stages of fruit development, while quercetogetin heptametoxiflavona and accumulate to a greater degree during stages of fruit ripening. In this communication we analyze the changes in phenolic compounds (flavanones and flavones) during development and in different parts of the ripe fruit of citrus sinensis (L.) Osbeck, cv Sanguinelli grown in Murcia (Spain). The distribution in the fruit of these compounds revealed that the glycosylated flavanones are found in higher concentrations in the albedo, while flavones polymethoxylated preferentially accumulate in the flavedo.