An make a continual flux of hydroxyl radicals [15,16]. (To simplify some reaction sequences appearing in this minireview, HA abbreviates the hyaluronan macromolecule. The IEM-1460 supplier Adenotes a C-centered hyaluronan macroradical, a peroxy-type macroradical AOOalong using a highly unstable alkoxy-type macroradical AOrepresents O-centered intermediate macroradicals).Polymer fragmentsHAPharmaceutics 2021, 13,Pharmaceutics 2021, 13,four of4 ofPolymer fragmentsHAMolar mass [Da]Figure two. Comparison in the molar mass distribution from the megadalton HA sample and those ones degraded in situ under aerobic condition by action of AscH- and copper ions. Adapted from [51], published by Elsevier, 2007.3.1. Hyaluronan Oxidative Degradation by Free-Radical-Chain Reaction three.1.1. Initiation Reaction(s)As shown in the Diversity Library custom synthesis sub-section “Sequestration of copper cations with ascorbate” for the four five six ten 10 10 generation of H radical(s) the so referred to as Weissberger biogenic oxidative program can make a continual flux mass [Da] radicals [15,16]. (To simplify some reaction sequences Molar of hydroxyl appearing in this minireview, HA abbreviates the hyaluronan macromolecule. The AdeFigure Comparison hyaluronan macroradical, of the megadalton HA sample sample and Figure two. two. Comparisonthe molar mass mass distribution from the megadalton HAAOOalong these o notes a C-centered of of your molar distribution a peroxy-type macroradicaland these ones degraded situ beneath aerobic condition by action action represents O-centered intermediate degraded in in situ below aerobic condition by of AscH- and copper ions. Adapted from [51], from [5 having a very unstable alkoxy-type macroradical AO f AscH- and copper ions. Adapted published Elsevier, 2007. published byby Elsevier, 2007. macroradicals.) The following Scheme 2 describes structural chemical formulae the phase of initiation 3.1. The followingOxidative describes structural chemical formulae the phase of initiation Hyaluronan Scheme 2 Degradation by Free-Radical-Chain Reaction reaction(s) of high-molar-mass HA oxidative degradation: reaction(s) of high-molar-mass HA oxidative degradation:three.1.1. Initiation Reaction(s)As shown in the sub-section “Sequestration of copper cations with ascorbate” for t generation of H radical(s) the so called Weissberger biogenic oxidative method can p duce a continual flux of hydroxyl radicals [15,16]. (To simplify some reaction sequen appearing in this minireview, HA abbreviates the hyaluronan macromolecule. The Ad notes a C-centered hyaluronan macroradical, a peroxy-type macroradical AOOalo having a extremely unstable alkoxy-type macroradical AOrepresents O-centered intermedi macroradicals.) The following Scheme two describes structural chemical formulae the phase of initiati reaction(s) of high-molar-mass HA oxidative degradation:Scheme 2. An intact HA macromolecule (upper panel) reacts with OH radical yielding an intermeScheme two. An intact HA macromolecule (upper panel) reacts with H radical yielding an intermediate A ,, i.e., a C-centered hyaluronan macroradical (reduced panel), which instantly reacts having a diate A i.e., a C-centered hyaluronan macroradical (decrease panel), which instantly reacts with molecule of of oxygen resulting inperoxy-type macroradical AOO. a molecule oxygen resulting inside a a peroxy-type macroradical AOOThe macroradical AOOcan undergo the reaction with Cu(I) complicated (cf. Scheme 1) yielding a hugely unstable alkoxy-type macroradical. It’s comprehensible that either AOOmacroradical or that.