Characterization of acidic heteroatoms in heavy petroleum fractions by phase-transfer methylation and NMR spectroscopy

1987 ◽  
Vol 1 (3) ◽  
pp. 233-239 ◽  
Author(s):  
K. D. Rose ◽  
M. A. Francisco
1977 ◽  
Vol 135 (2) ◽  
pp. 514-520 ◽  
Author(s):  
J.C. Hodgin ◽  
M.A. Kaiser ◽  
J.A. Lubkowitz ◽  
L.B. Rogers

1996 ◽  
Vol 117 (1-2) ◽  
pp. 211-216 ◽  
Author(s):  
P. Alessi ◽  
A. Cortesi ◽  
I. Kikic ◽  
E. Neau

2020 ◽  
Vol 4 (1) ◽  
pp. 15
Author(s):  
Eduardo Ravelo-Nieto ◽  
Alvaro Duarte-Ruiz ◽  
Luis H. Reyes ◽  
Juan C. Cruz

Several biological barriers are generally responsible for the limited delivery of cargoes at the cellular level. Fullerenols have unique structural features and possess suitable properties for interaction with the cells. This study aimed to synthesize and characterize a fullerenol derivative with desirable characteristics (size, charge, functionality) to develop cell penetration vehicles. Fullerenol was synthesized from fullerene (C60) solubilized in toluene, followed by hydroxylation with hydrogen peroxide and tetra-n-butylammonium hydroxide (TBAH) as a phase transfer catalyst. The obtained product was purified by a Florisil chromatography column (water as the eluent), followed by dialysis (cellulose membrane dialysis tubing) and freeze-drying (yield 66%). Subsequently, a silane coupling agent was conjugated on the fullerenol surface to render free amine functional groups for further covalent functionalization with other molecules. Characterization via UV–VIS, FTIR-ATR, Raman, DLS, and SEM techniques was conducted to evaluate the composition, size, morphology, surface functionality, and structural properties. We are currently working on the conjugation of the potent cell-penetrating agents Buforin II (BUFII) and the Outer Membrane Protein A (OmpA) on the surface of the fullerenol to estimate whether cell penetration and endosome escape are improved concerning conventional polymeric vehicles and our previous developments with iron oxide nanoparticles.


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