Self-association of benzylpenicillin in aqueous solution: 1H nuclear magnetic resonance study

Abstract

Concentration dependence of lH n.m.r. spectra appears to have been made to correlate this concentration suggests that benzylpenicillin ions aggregate in aqueous dependence with association properties of penicillins. solution primarily through hydrophobic interactions of Controversial reports have been made regarding the state the benzyl side chains.of penicillin salts in aqueous solutions ; on the one hand they are said to behave as simple 1 : 1 electrolytes;% and on the other, to behave as colloidal electrolytes and to form micellar aggregate^.^,^ We report a 1H n.m.r. study that ALTHOUGH n.m.r. spectra of aqueous solutions of penicillins are known to be concentration dependent,l no attempt

Self-association of Verapamil in Aqueous Electrolyte Solution

“…Upfield shifts on increase of concentra- tion were larger in the case of the aromatic protons (Table 2) indicative of an intermolecular ring current effect as the two phenyl ring systems associate to form the micelle core (12,13). Similar upfield shifts of the aromatic protons have been noted, for example, for the micellization of ω-phenylalkyltrimethylammonium bromides (14, 15) and sodium ω-phenyl decanoate (16) and are also characteristic of compounds that exhibit a stacking mode of association such as nucleotides (17), dyes (18,19), phenothiazine drugs (20), and penicillins (21,22). Protons 2 and 4 corresponding to methyl groups adjacent to the phenyl ring undergo smaller upfield shifts, while proton 3 situated on the alkyl chain shows a small downfield shift.…”

Self Association of Folic Acid in Aqueous Solution by Proton Magnetic Resonance

“…philic groups all next to each other (head-to-fore it is unlikely that folate ions undergo head interaction) or in a vertical stack with the micelle formation as do the benzylpenicillin hydrophilic ends of the molecule alternating in ions (22).…”

“…Besides these intramolecular interactions, intermolecular association equilibria must be considered. Nucleosides and nucleotides stack in solution (20, 21) whereas benzylpenicillin ions (22) form micelles. Based on a temperature and concentration dependence of the proton chemical shifts, disodium folate exists in solution in an extended, non-folded conformation.…”

The diffusion of penicillin G and ampicillin through phospholipid sols

“…Penicillin G has been ascribed a cmc by some authors (e.g. Hauser, Phillips & others, 1949;McBain, Huff & Brady, 1949;Thakkar & Wilham, 1970), whereas others (e.g. Lund & Pedersen-Bjergaard, 1949;Goyan, 1949;Hocking, 1951;Few & Schulman, 1953), have not observed surface activity.…”