Hydrolytic activity of acetonic powders from leaves and berries of "Muscat" varieties on terpene glycosides

anglais. In experiments in a phosphate-citrate buffer at pH = 5, with free linalool and geraniol or with terpene glycosides as substrates of acetonic powder from White Muscat leaves, it was impossible to detect epoxydase or hydroxylase activities. Instead, the acetonic powder of leaves showed hydrolytic activities (glycosidase or beta-glucosidase activity) with respect to some glycosides of mono and dihydroxylated primary and tertiary alcohols, of linalool oxydes and of trans-geranic acid. The acetonic powder of leaves appears to be different from that of berries because the latter is able to hydrolyze only particular glycosilated forms of primary alcohols and of geranic acid. Both acetonic powders of leaves and of berries show a little activity on glycosilated forms of linalool

italien. Utilizzando linalolo e geraniolo liberi o composti terpenici glicosilati come substrato della polvere acetonica ottenuta da foglie di Moscato bianco, in tampone fosfato-citrato a pH = 5, non fu possibile mettere in luce attivita' enzimatiche epossidasiche o idrossilasiche. La stessa polvere acetonica, nello stesso tampone, rivelo' invece attivita' idrolitica nei riguardi di particolari forme glicosilate degli alcoli terpenici mono e diidrossilati, pRimari e terziari, degli ossidi del linalolo e dell'acido geranico. Per questa proprieta', essa si difFerenzia dalla polvere acetonica degli acini, che e' in grado di idrolizzare solo particolari forme glicosilate degli alcoli monoidrossilati primari e dell'acido geranico. Risulta scarsa l'attivita' di entrambe le polveri acetoniche nei riguardi delle forme legate del linalolo