Structural modifications of abietic acid and a computational protocol to predict their compatibility in different...

Abietic acid, a major diterpenoid of rosin, is a renewable feedstock with wide industrial relevance. However, its polarity limits compatibility with apolar environments. A computational protocol has been developed to predict how structural modifications of abietic acid influence molecular polarity and compatibility with different environments. A representative series of abietic acid derivatives was selected for the theoretical study, including non-carbonyl derivatives and two new long-chain esters, dodecyl and hexadecyl abietates. An extensive molecular mechanics conformational search, followed by DFT optimizations, enabled the estimation of population-weighted dipole moments and Gibbs free energies of solvation in solvents of different polarity (pentyl ethanoate and n-octane). The resulting descriptors were compared with experimental HPLC-DAD retention times and thin-layer chromatography R _f values, showing good agreement between computed and experimental trends. The calculations correctly capture subtle conformational effects, including the pseudo-amphiphilic character of dodecyl abietate arising from folded conformations. Overall, the computational framework provides a predictive tool for guiding the rational design of abietic acid derivatives with tailored polarity.