*3.2.1.1.1. Abietic acid*

*3.1.2. Labdanes*

116 Terpenes and Terpenoids

described in this chapter as well (**Figure 4**).

**3.2. Tricyclic diterpenoids**

etane as standard (**Figure 6**).

*3.2.1.1. Tricyclic abietatrienes*

**Figure 4.** Skeleton of labdanes.

See **Figure 5**

*3.2.1. Abietanes*

The labdane-related diterpenoids are a special group, consisting of over 7000 members, which are distinguished by their unique biosynthesis. Gibberellin phytohormones as well as antibiotics such as some of phytoalexins and phytoanticipins fall into this family [34]. Labdanolic acids have been identified as biomarkers for the botanical origin of French ambers [35], while copalic acid and its relatives have been associated with the biological activity of the resins from *Copaifera* species. The lanceolatins are a group of **labdanes** and **abietanes** which were obtained [40] from *Cephalotaxus lanceolata* (Cephalotaxaceae). Some of the abietanes were

Abietane is a class of diterpenoids with excellent metabolic profile. Compounds of this class showed broad spectrum antiviral, antibacterial, and antifungal activity [36, 37]. Abietane diterpenoids are extracted from few fungal species [38]. The intervention of quinone methides in the antioxidant activity of the phenolic diterpenoids ferruginol and carnosic acid has been discussed. The antifungal activity of some abietic acid esters in the context of their use as wood preservatives and the antiviral activity of podocarpic acid derivatives have been examined. In case of human cells, antiproliferative effect on tumor cells has been reported [39].

About 200 compounds of this family have been identified commonly known as dehydroabietic derivatives (dehydroabietanes) [40] assuming 20-carbon saturated aromatic ring I, abi-

This group of abietane terpenes includes a tricyclic ring, three double bonds on B or C rings. Carboxylic acids are representatives of this group, of which the earliest example is the biologi-

cally active dehydroabietic acid (**Figure 6**), which possess an acid group at C-18 [42].

Abietic acid was extensively studied in various organisms for its biological activities. Current data also suggest that abietic acid is an important compound for synthesis of novel metabolites. They contribute to the body of knowledge related to compound 1 and deepen the understanding of the potential and properties of 1 and its derivatives (**Figure 7**).
