https://www.selleckchem.com/products/abt-199.html To gain insight into the mechanisms of ionophoric activity of usnic acid (UA), we examined the UA-induced generation of potentials on a planar bilayer lipid membrane (BLM) in the presence of concentration gradients of hydrogen and magnesium or calcium ions under open-circuit conditions. Remarkably, the BLM potential generated by UA at the proton concentration gradient of 1 pH unit was approximately twice the Nernst equilibrium level. With a concentration gradient of magnesium or calcium ions, the BLM potential generated by UA had the opposite sign. The observed anomalies in the membrane potentials were consistent with a theory developed by Markin and Sokolov (Bioelectrochem. Bioenerg. 1990) for the case of ionophore-mediated coupled fluxes of several ions across a membrane.This novel study investigated the fate and distribution in soils, and potential exposure risk of glyphosate, an extensively used herbicide in urban landscapes. The rate-determining step of glyphosate sorption in urban soils involved chemisorption processes through exchange or sharing of electrons that followed the pseudo-second-order kinetics model. As evidenced by the Freundlich isotherm model, glyphosate gets partitioned into heterogeneous surfaces of soil organic matter (OM) and clay minerals, and then diffused into soil micropores. The principal component analysis revealed that soil OM (R2 = 0.873), oxides of Al (R2 = 0.361) and Fe (R2 = 0.126), and contents of clay (R2 = 0.061) and silt (R2 = 0.432) were positively correlated with the distribution coefficient (Kd) of glyphosate, while alkaline pH (R2 = -0.389) and sand content (R2 = -0.343) negatively correlated with the Kd values. Well-decomposed soil OM, consisting of C-H and CO functional groups, enhanced glyphosate sorption, whereas partially decomposed/undecomposed OM facilitated desorption process. Desorption of glyphosate was favoured in seven of nine selected soils due to adverse hyste