Fig. 4: Experimental evidence of SNAC aggregation in polar and non-polar environments.
From: Permeation enhancer-induced membrane defects assist the oral absorption of peptide drugs
A Stacked convection-compensated 1H DOSY NMR spectra (800 MHz, 298 K, D2O, pH = 7.4 in PBS Buffer, pulse sequence: dstebpg3s) of 100 mM SNAC (black), 2.5 mM semaglutide (blue), and a mixture of 100 mM SNAC and 2.5 mM semaglutide (red). Diffusion coefficients and hydrodynamic radii are detailed in Table 1. B DLS spectra (298 K, mean intensity ± standard deviation, n = 10) of SNAC in 50 mM solutions of CTAB demonstrating incorporation of SNAC into surfactant micelles. Additional DLS spectra of the conjugate acid of SNAC aggregating in non-polar solvents (CDCl3) are provided in Supplementary Fig. 4. C 1H-1H NOESY NMR (500 mHz, 298 K, D2O, pH = 5.6, pulse sequence: noesygpph) spectra of 40 mM SNAC and 50 mM CTAB with highlighted crosspeak signals to indicate the incorporation of SNAC in the CTAB micelle. D Crosspeak intensities of SNAC (n = 3, labeled in Fig. 4C and referenced to the ω CTAB diagonal intensity) are concentration dependent. Solutions for the NOESY and DLS titration experiments were buffered with SNAC at pH = 5.6 by using a 4:1 mixture of SNAC and its conjugate acid. Data are provided as mean values ± SD. Source data are provided as a Source Data file.
