H-1-NMR STUDY OF PHENOLICS IN THE VEGETATION WATER OF 3 CULTIVARS OF OLEA-EUROPAEA - SIMILARITIES AND DIFFERENCES

In this work free phenolics and phenolic glucosides present in the wat er content (vegetation water, VW) of olive fruits of the three Italian cultivars (cvs.) Cipressino, Dritta, and Leccino were identified by H -1 NMR. The phenolic metabolite content of the three cultivars was stu died at three fruit growth stages. The major phenolic compounds, commo n to all three cultivars, were 4-hydroxyphenylethanol (tyrosol) (1), 4 -hydroxyphenylethanol glucoside (2), and oleuropein (3). Considerable differences in the content of compounds (1-3) were found to occur in t he fruits during growth and maturation of the drupe. Glucoside (4), a major component of the low molecular weight solutes of Dritta and Lecc ino cvs., was not detected in Cipressino fruits. The quinol glucoside (4) was thought to derive from oxidation of the glucoside of 4-hydroxy phenylethanol (2). Hydrolysis of (4) followed by cyclization yielded t he bicyclic compound halleridone (5).