Macrocyclic Oligoesters Incorporating a Cyclotetrasiloxane Ring.
Biomacromolecules
; 16(7): 2091-100, 2015 Jul 13.
Article
em En
| MEDLINE
| ID: mdl-26061086
ABSTRACT
Macrocyclic oligoester structures based on a cyclotetrasiloxane core consisting of tricyclic (60+ atoms) and pentacycylic (130+ atoms) species were identified as the major components of a lipase-mediated transesterification reaction. Moderately hydrophobic solvents with log P values in the range of 2-3 were more suitable than those at lower or higher log P values. Temperature had little effect on total conversion and yield of the oligoester macrocycles, except when a reaction temperature of 100 °C was employed. At this temperature, the amount of the smaller macrocycle was greatly increased, but at the expense of the larger oligoester. For immobilized lipase B from Candida antarctica (N435), longer chain length esters and diols were more conducive to the synthesis of the macrocycles. Langmuir isotherms indicated that monolayers subjected to multiple compression/expansion cycles exhibited a reversible collapse mechanism different from that expected for linear polysiloxanes.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Siloxanas
/
Proteínas Fúngicas
/
Lipase
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article