Conformational search of scytonemin and its stereoisomers from first-principles: Towards green cosmetics

Scytonemin is a UV-absorbing metabolite produced by cyanobacteria that may be used as a sustainable sunscreen ingredient. However, ab initio studies on scytonemin structure and excited states are sparse. We present herewith a theoretical study to predict its molecular structure using density functional theory. Predicted conformational energy barriers from the def2-QZVPP basis and select exchange-correlational functionals were benchmarked against a coupled-cluster calculation at the basis set limit.