title: Hydrolyzable tannins with the hexahydroxydiphenoyl unit and the m-depsidic link: HPLC-DAD-MS identification and model synthesis.
abstract: This study was designed to develop efficient analytical tools for the difficult HPLC-DAD-MS identification of hydrolyzable tannins in natural tissue extracts. Throughout the study of the spectroscopic characteristics of properly synthesized stereodefined standards, it was observed that the UV-vis spectra of compounds with the m-depsidic link showed a characteristic shoulder at 300 nm, consistent with the simple glucogalloyl esters, whereas compounds with the hexahydroxydiphenoyl (HHDP) unit gave a diagnostic fragmentation pattern, caused by a spontaneous lactonization in the mass spectrometer. These observations were confirmed by HPLC-DAD-MS analyses of tannic acid and raspberry extracts, which are rich in hydrolyzable tannins with the m-depsidic link and the HHDP unit, respectively.
authors.affiliation: Dipartimento di Scienze Farmaceutiche, Polo Scientifico e Tecnologico, Università degli Studi di Firenze, Via U. Schiff 6, 50019 Sesto Fiorentino (FI), Italy.
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Arapitsas
authors.forename: Stefano
authors.initials: S
authors.lastname: Menichetti
authors.forename: Franco F
authors.initials: FF
authors.lastname: Vincieri
authors.forename: Annalisa
authors.initials: A
authors.lastname: Romani
mesh_terms: D002851:Chromatography, High Pressure Liquid; D005707:Gallic Acid / Q000032:analysis / Q000737:chemistry; D005947:Glucose / Q000737:chemistry; D006868:Hydrolysis; D047348:Hydrolyzable Tannins / Q000032:analysis; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D013634:Tannins / Q000032:analysis* / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D047348:Hydrolyzable Tannins; D013634:Tannins; C435084:pentagalloylglucose; D005707:Gallic Acid; D005947:Glucose