The solution structure of rifaximin and its derivative rifaximin OR (open ring) was determined by combining NMR experimental results, theoretical simulation of two-dimensional NMR spectra by complete relaxation matrix analysis (CORMA), and molecular dynamics calculations. In this study the structural rearrangements due to the opening of the aliphatic chain of rifaximin after the reduction process to form rifaximin OR were investigated. Close spatial proximity of CH(14) and H28b protons detected by 2D-ROESY spectrum of rifaximin OR, which was not present in rifaximin and the down-ﬁeld shift of CH3(34) protons in rifaximin OR 1H spectrum were crucial to understand the structuralmodiﬁcations, which occurred within the system. The aliphatic chain of rifaximin OR was found to be no longer symmetrical withrespect to the aromatic moiety. Although no dramatic structural rearrangements were detected, the aliphatic chain moved toward CH3(14), causing a reduction of the aromatic shielding contribution in particular on CH(34).
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|Titolo:||Solution Structure of Rifaximin and its Synthetic Derivative Rifaximin OR determined by Experimental NMR and Theoretical Simulation Methods|
|Citazione:||Martini, S., Bonechi, C., Corbini, G., Donati, A., & Rossi, C. (2004). Solution Structure of Rifaximin and its Synthetic Derivative Rifaximin OR determined by Experimental NMR and Theoretical Simulation Methods. BIOORGANIC & MEDICINAL CHEMISTRY, 12 (9), 2163-2172.|
|Appare nelle tipologie:||1.1 Articolo in rivista|