A computational investigation of sulfur-containing heterocyclic components from the anal sac secretions of Mustela species.

A computational investigation of the sulfur-containing heterocyclic components (substituted thietanes and 1,2-dithiolanes) of Mustela anal sac secretions has been carried out. A cluster analysis of the chemical compositions of Mustela anal sac volatiles reveals little similarity with established phylogenetic relationships between members of the genus. Ab initio calculations [MP2/6-311++G(2df,2p)//B3LYP/6-311++G**] show the lowest-energy C5H10S isomeric thietane to be 2,2-dimethylthietane, which is also the most abundant of the Mustela thietanes. Similarly, 3,3-dimethyl-1,2-dithiolane is the lowest-energy C5H10S2 compound. 2-n-Propylthietane is the highest-energy C6H12S compound, but the most abundant Mustela C6H12S compound produced, whereas cis-2-ethyl-4-methylthietane, the lowest-energy C6H12S thietane, has never been observed in Mustela anal sac secretions. A molecular docking analysis of the Mustela sulfur-containing heterocycles into both porcine and bovine odorant binding proteins reveals the interactions of the docked ligands with the proteins to be largely hydrophobic, and have binding energies generally lower than typical odorant molecules such as linalool or eugenol.