TY - JOUR
T1 - Conformational and dynamical study of squalene derivatives – Vynil Oxidosqualenes
AU - POGLIANI, L.
AU - ROSSI, P.
AU - PAOLI, P.
AU - CERUTI, M.
AU - MILANESIO, Marco
N1 - Funding Information:
Thanks are due to professors Ivano Bertini and Lucia Banci of the Chemistry Department of the University of Firenze, Italy, for the availability of the 600-MHz NMR facility, and to M. Lucci, E. Morelli and S. Rocchi of the same department for their help and assistance. Thanks are also due to professor Paolo Dapporto of the Department of Energetics of the University of Firenze, Italy, for the computer facility, and to professor Davide Viterbo for critical reading of the manuscript. We would also like to thank one of the referees for his helpful and interesting suggestions. This work was supported by grants from the MURST (Ministero per l’Universita’ e per la Ricerca Scientifica e Tecnologica) and from CNR (Consiglio Nazionale delle Ricerche).
PY - 1999
Y1 - 1999
N2 - Five different squalene derivatives, (1) (18Z)-29-methylidene-2,3-oxidohexanor-squalene; (2) (18E)-29-methylidene-2,3-oxidohexanorsqualene; (3) 18-heptanor-2,3-oxido-squalene 3; (4) (18Z)-29-hydroxy-2,3-oxidosqualene; and (5) (18E)-29-hydroxy-2,3-oxido-squalene, were studied with both theoretical and experimental methods. Chloroform solutions of these compounds were studied with different mono-, bidimensional and relaxation NMR methods. Analysis of the NMR spectroscopic data of these molecules in solution indicates that their central portion is relatively rigid, while their terminal portions are rather mobile. Further, NMR data of compounds 1 and 2 show that the cis conformation of the butadiene-like terminal group is the most stable conformation. Molecular mechanics and dynamic calculations in vacuum indicate that the mobility of the long squalene-like chain in compounds 1-3 is almost equivalent in all isoprenic moieties and that the higher mobility of the tails seems to be due to a cooperative increase of mobility in going from the center to the end of the chain. Theoretical results show that in compounds 4 and especially 5 there is a strong evidence of folded structures in vacuum, while in chloroform small percentages of folded structures become evident even for compounds 1-3. Copyright (C) 1999 Elsevier Science Ireland Ltd.
AB - Five different squalene derivatives, (1) (18Z)-29-methylidene-2,3-oxidohexanor-squalene; (2) (18E)-29-methylidene-2,3-oxidohexanorsqualene; (3) 18-heptanor-2,3-oxido-squalene 3; (4) (18Z)-29-hydroxy-2,3-oxidosqualene; and (5) (18E)-29-hydroxy-2,3-oxido-squalene, were studied with both theoretical and experimental methods. Chloroform solutions of these compounds were studied with different mono-, bidimensional and relaxation NMR methods. Analysis of the NMR spectroscopic data of these molecules in solution indicates that their central portion is relatively rigid, while their terminal portions are rather mobile. Further, NMR data of compounds 1 and 2 show that the cis conformation of the butadiene-like terminal group is the most stable conformation. Molecular mechanics and dynamic calculations in vacuum indicate that the mobility of the long squalene-like chain in compounds 1-3 is almost equivalent in all isoprenic moieties and that the higher mobility of the tails seems to be due to a cooperative increase of mobility in going from the center to the end of the chain. Theoretical results show that in compounds 4 and especially 5 there is a strong evidence of folded structures in vacuum, while in chloroform small percentages of folded structures become evident even for compounds 1-3. Copyright (C) 1999 Elsevier Science Ireland Ltd.
UR - https://iris.uniupo.it/handle/11579/9522
M3 - Article
SN - 0009-3084
VL - 103
SP - 67
EP - 79
JO - Chemistry and Physics of Lipids
JF - Chemistry and Physics of Lipids
ER -