BIOACTIVE COMPOUND CONTENTS IN DIFFERENT VARIETIES OF SUNFLOWER SPROUTS AND GENES INVOLVED IN CAFFEOYL QUINIC ACID DERIVATIVE BIOSYNTHESIS

Abstract

At present, sunflower sprouts (Helianthus annuus) are popularly consumed because they accumulate several kinds of nutrients and bioactive compounds. In this study, six varieties of sunflower sprouts, namely, 5A, 10A, S473, S475, unknown variety from internet shop “Lungtoporganic” (UNK), and unknown variety from Chiatai company (CH) were compared for bioactive compound contents. The results demonstrated that UNK contains the highest amounts of antioxidants and total phenolic compounds including cynarin. At different germination times, 5A and CH varieties showed that the antioxidant activities and total phenolic contents were highest at day 3. However, the chlorogenic acid and cynarin amounts in 5A were not associated with those results. Chlorogenic acid and cynarin levels in chitosan-elicited sunflower sprouts mostly remained stable in 5A and decreased in CH, while, antioxidant and total phenolic contents slightly increased. Methyl jasmonate application strongly induced the amounts of antioxidants and total phenolics in sunflower sprouts. This study also suggests that chlorogenic acid and cynarin are the major compounds having antiglycative activity. From database searching for genes involved in caffeoyl quinic acid derivative biosynthesis, three candidate genes including hydroxycinnamoyl-CoA:quinate hydroxyl cinnamoyltransferase (HQT), namely, HaHQT1, HaHQT2, and HaHQT3 were found. The HaHQT1 shows the highest gene expression level, therefore, it supposed to be a gene responsible for chlorogenic acid and cynarin biosyntheses in sunflower sprouts. Content analysis of bioactive compounds can be performed to select the most suitable variety for further breeding to increase the amounts of bioactive compound in the future.