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13 C‐CPMAS and 1 H‐NMR Study of the Inclusion Complexes of β ‐Cyclodextrin with Carvacrol, Thymol, and Eugenol Prepared in Supercritical Carbon Dioxide
Author(s) -
Locci Emanuela,
Lai Simona,
Piras Alessandra,
Marongiu Bruno,
Lai Adolfo
Publication year - 2004
Publication title -
chemistry and biodiversity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.427
H-Index - 70
eISSN - 1612-1880
pISSN - 1612-1872
DOI - 10.1002/cbdv.200490098
Subject(s) - chemistry , eugenol , carvacrol , thymol , carbon 13 nmr , supercritical carbon dioxide , aqueous solution , proton nmr , inclusion (mineral) , supercritical fluid , cyclodextrin , nuclear chemistry , organic chemistry , chromatography , essential oil , mineralogy
β ‐Cyclodextrin ( β ‐CD) inclusion complexes with carvacrol ( 1 ), thymol ( 2 ), and eugenol ( 3 ) (components of essential oils of vegetable origin) were prepared by the supercritical CO 2 technique, and their structural characterization was achieved by means of 1 H‐NMR in aqueous solution and 13 C‐CPMAS NMR in the solid state. Evidence of the formation of the inclusion complexes for all the examined systems was obtained by 1 H‐NMR in solution, while 2D‐ROESY‐NMR experiments were used to investigate the geometry of inclusion. In addition, the dynamics of these inclusion complexes in the kHz timescale was investigated by analysis of the 1 H and 13 C spin‐lattice relaxation times in the rotating frame.