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Biosynthesis of naringin in Citrus Paradisi: UDP-glucosyltransferase activity in grapefruit seedlings.
Phytochemistry (1990)
  • Cecilia A. McIntosh, East Tennessee State University
  • Richard L. Mansell, University of South Florida
A UDP-glucosyltransferase activity capable of position-specific transfer of glucose to the 7-position of naringenin has been isolated from grapefruit seedlings. Leaves are the richest source of this activity on a fresh weight basis. Characteristics include a pH optimum of 6.5–7.5, a temperature optimum of 37°, an apparent Eact of 7.76 kcal mol−1, and an apparent Km for naringenin of 0.08 mM. Hesperitin and 2′,4′,6′,4-tetrahydroxychalcone are also glucosylated with apparent Km's of 0.11 mM and 0.13 mM respectively. Thermal degradation studies indicate that the naringenin and hesperitin glucosylating activities have different stabilities. Chromatofocusing resolves the naringenin glucosylating activity into two peaks with apparent pI's of 4.4 and 3.9. The hesperitin glucosylating activity separates into three peaks with apparent pI's of 4.5, 4.4, and 4.0.
  • Citrus paradise,
  • Rutaceae,
  • grapefruit,
  • biosynthesis,
  • naringin,
  • pruning,
  • hesperitin 7-glucoside,
  • UDP-glucosyltransferase
Publication Date
Citation Information
McIntosh, C. A., & Mansell, R. L. (1990). Biosynthesis of naringin in Citrus paradisi: UDP-glucosyl-transferase activity in grapefruit seedlings. Phytochemistry, 29(5), 1533–1538.