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On the Mechanism of Genipin Binding to Primary Amines in Lactose-Modified Chitosan at Neutral pH

The present manuscript deals with the elucidation of the mechanism of genipin binding by primary amines at neutral pH. UV-VIS and CD measurements both in the presence of oxygen and in oxygen-depleted conditions, combined with computational analyses, led to propose a novel mechanism for the formation...

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Detalles Bibliográficos
Autores principales: Pizzolitto, Chiara, Cok, Michela, Asaro, Fioretta, Scognamiglio, Francesca, Marsich, Eleonora, Lopez, Francesco, Donati, Ivan, Sacco, Pasquale
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7554727/
https://www.ncbi.nlm.nih.gov/pubmed/32957651
http://dx.doi.org/10.3390/ijms21186831
Descripción
Sumario:The present manuscript deals with the elucidation of the mechanism of genipin binding by primary amines at neutral pH. UV-VIS and CD measurements both in the presence of oxygen and in oxygen-depleted conditions, combined with computational analyses, led to propose a novel mechanism for the formation of genipin derivatives. The indications collected with chiral and achiral primary amines allowed interpreting the genipin binding to a lactose-modified chitosan (CTL or Chitlac), which is soluble at all pH values. Two types of reaction and their kinetics were found in the presence of oxygen: (i) an interchain reticulation, which involves two genipin molecules and two polysaccharide chains, and (ii) a binding of one genipin molecule to the polymer chain without chain–chain reticulation. The latter evolves in additional interchain cross-links, leading to the formation of the well-known blue iridoid-derivatives.