The compounds in LANaPDB were structurally classified according to a classification system based on the literature from the specialized metabolism of plants, marine organisms, fungi, and microorganisms. The classification system is divided in three hierarchical levels: pathway (nature of the biosynthetic pathway), superclass (chemical properties or chemotaxonomic information) and class (structural details). At the three hierarchical levels, the predominant compounds are the terpenoids (Figure ). At the hierarchical level of pathway, the terpenoids, shikimates, phenylpropanoids, and alkaloids encompass more than 90% of the total compounds. At the hierarchical level of superclass and class, the terpenoids and the flavonoids were the predominant compounds (Figure ). The above was expected because the terpenoids are the predominant secondary metabolites produced by natural sources. Compared to the previous version of LANaPDB the above tendencies have not changed. 22