- 1H, 13C NMR, FT-IR, ESI MS and PM5 studies of a new 3,6,9-trioxadecylamide of monensin A and its complexes with Li+, Na+ and K+ cations
-
A new 3,6,9-trioxadecylamide of monensin A (M-AM4) has been synthesised and its ability to form complexes with Li+, Na+ and K + cations has been studied by ESI mass spectrometry, 1H and 13C NMR, FT-IR spectroscopy and PM5 semiempirical method. The ESI MS data indicate that M-AM4 forms complexes with Li+, Na+ and K+ of exclusively 1:1 stoichiometry which are stable up to cv = 70 V. The formation of the M-AM4-Na+ is strongly favoured. Above cv = 70 the fragmentation process is observed. The spectroscopic studies show that the structures of the M-AM4 and its complexes with the cations of 1:1 stoichiometry are stabilized by intramolecular hydrogen bonds in which the OH groups are always involved. The CO amide group is engaged in the complexation process of each cation. The M-AM4-K+ complex can also assume a structure in which the CO amide group does not participate in the complexation but the complexes of such structure do not dominate.
- ?owicki, Daniel,Huczyński, Adam,Brzezinski, Bogumil,Bartl, Franz
-
experimental part
p. 121 - 131
(2011/04/23)
-
- Novel 3-O-pegylated carboxylate and 3-O-pegylated carbamate prodrugs of naltrexone for microneedle-enhanced transdermal delivery
-
A small library of novel 3-O-pegylated carboxylate prodrugs (4a-4b) and 3-O-pegylated carbamate prodrugs (9a-9b) of naltrexone were synthesized. The goal behind the design of these prodrugs was to investigate their potential for microneedle-enhanced transdermal delivery. All the synthesized 3-O-pegylated carboxylate prodrugs (4a-4b) and 3-O-pegylated carbamate prodrugs (9a-9b) of naltrexone were found to have adequate stability in a transdermal formulation and improved apparent solubility compared to naltrexone. Viscosity effects were postulated to be responsible for the observed non-linearity in the flux-concentration profile of these prodrugs.
- Yerramreddy, Thirupathi Reddy,Milewski, Mikolaj,Penthala, Narsimha Reddy,Stinchcomb, Audra L.,Crooks, Peter A.
-
scheme or table
p. 3280 - 3283
(2010/08/19)
-