Structure and conformation of protonated D-(+)-biotin in the unsolvated state.
A combined computational and infrared multiphoton dissociation (IRMPD) spectroscopic investigation shows that protonated d-(+)-biotin, formed in the gas phase by ESI-MS, acquires a folded structure with proton bonding between the ureido and valeryl carbonyls, and that only a single conformer of such a structure predominates. A uniform frequency vs distance correlation function is proposed for the O(+)-H···O and N-H···O bonds involved in the folded conformers of O2'-protonated d-(+)-biotin in the gas phase which, therefore, depends exclusively on the corresponding geometric parameters.
†Dipartimento di Chimica e Tecnologie del Farmaco, Università "La Sapienza", Roma, Italy.
Caterina
C
Fraschetti
†Dipartimento di Chimica e Tecnologie del Farmaco, Università "La Sapienza", Roma, Italy.
Antonello
A
Filippi
†Dipartimento di Chimica e Tecnologie del Farmaco, Università "La Sapienza", Roma, Italy.
Laura
L
Guarcini
‡Laboratoire Chimie Physique, UMR8000 CNRS, Université Paris Sud 11, Orsay, France.
Vincent
V
Steinmetz
†Dipartimento di Chimica e Tecnologie del Farmaco, Università "La Sapienza", Roma, Italy.
Maurizio
M
Speranza
D001710:Biotin / Q000737:chemistry*; D005740:Gases / Q000737:chemistry; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008968:Molecular Conformation; D011522:Protons; D021241:Spectrometry, Mass, Electrospray Ionization
D005740:Gases; D011522:Protons; D001710:Biotin