Synthesis of a thiol-β-cyclodextrin, a potential agent for controlling enzymatic browning in fruits and vegetables.
A thiol-β-cyclodextrin was synthesized by a simple and environmentally friendly three-step method comprising epoxy activation of β-cyclodextrin, thiosulfate-mediated oxirane opening, and further reduction of the S-alkyl thiosulfate to a thiol group. The final step was optimized by using thiopropyl-agarose, a solid phase reducing agent with many advantages over soluble ones. β-Cyclodextrin thiolation was confirmed by titration with a thiol-reactive reagent, NMR studies, and MALDI-TOF/TOF. Thiolated cyclodextrin had an average value of one thiol group per molecule. Thiol-β-cyclodextrin proved to be an excellent agent for controlling polyphenol oxidase activity. This copper-containing enzyme is responsible for browning in fruits and vegetables. Under the same conditions, thiol-β-cyclodextrin generated a reductive microenvironment that increased the antibrowning effect on Red Delicious apples compared to unmodified β-cyclodextrin.
Cátedra de Bioquı́mica, Departamento de Biociencias, Facultad de Quı́mica, Universidad de la República , Gral Flores 2124, Montevideo, Uruguay.
Carmen
C
Manta
Gabriela
G
Peralta-Altier
Larissa
L
Gioia
María F
MF
Méndez
Gustavo
G
Seoane
Karen
K
Ovsejevi
D004156:Catechol Oxidase / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D027845:Malus / Q000378:metabolism; D013438:Sulfhydryl Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D047392:beta-Cyclodextrins / Q000138:chemical synthesis* / Q000737:chemistry* / Q000494:pharmacology*
D013438:Sulfhydryl Compounds; D047392:beta-Cyclodextrins; C000591091:thiol-beta-cyclodextrin; D004156:Catechol Oxidase; C031215:betadex