Aglycone and glycoside specificity of apple skin flavonoid glycosyltransferase

✍ Scribed by Lister, Carolyn E; Lancaster, Jane E; Sutton, Kevin H; Walker, John R L

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 173 KB
• Volume: 75
• Category: Article
• ISSN: 0022-5142
• DOI: 10.1002/(sici)1097-0010(199711)75:3<378::aid-jsfa887>3.0.co;2-z

✦ Synopsis

O-Glycosyltransferase(s) extracted from apple (Malus pumila Mill) fruit skin showed activity towards a range of Ñavonols and anthocyanins. However, no glycosylating activity was shown towards a dihyroÑavonol (dihydroquercetin), a Ñavanone (eriodictyol) or a Ñavone (luteolin). The enzyme preparation glycosylated those Ñavonoids normally present in apple skins (quercetin and cyanidin) and in addition several other related compounds (delphinidin, Ðsetin, isorhamnetin, kaempferol, myricetin and pelargonidin). This enzyme(s) speciÐcally transferred the glycosyl moiety from sugar nucleotide donors to the 3-position of the Ñavonoid nucleus. Only Ñavonoid 3-glycosides occur naturally in apple skin. Activity with di †erent sugar donors was in the order galactose [ glucose [ xylose, which reÑected the ratios of cyanidin and quercetin glycosides found in apple fruit skin. There were slight di †erences in the relative UFGT activity with quercetin and the three di †erent sugar donors between "Granny SmithÏ and "SplendourÏ, and this was reÑected by similar di †erences in the ratios of endogenous quercetin glycosides.