Pine resin is mainly composed of diterpene compounds such as monoterpenes, sesquiterpenes, and resin acids, which are the main components of turpentine, heavy turpentine (that is, heavy oil) and rosin. Rosin may also contain varying degrees of fatty acids and other hydrocarbons (alkanes and aromatics) depending on the tree species. When rosin is distilled, the monoterpene has a low boiling point and is distilled first, and the main component is turpentine; resin acid has a high boiling point, and remains in the distillation pot as the main component of rosin; the boiling point is between the two. The few sesquiterpenes, Part of it enters the turpentine with the monoterpenes, and some remains in the rosin, and most of the sesquiterpenes may also be the main content of the separately collected fraction heavy turpentine.
There are obvious differences in the chemical composition of the physiological turpentine existing in the leaves, branches and stems of the pine tree and the pine resin secreted, and some components are closely related to pine tree diseases and insect pests. In addition, after long-term research, there are obvious differences in the chemical composition of pine resins due to different pine varieties. Even if the pine resins are produced from the same variety, there are certain differences due to the differences between the north and the south of the region.