**1. Terpenes and terpenoids**

Natural products are the compounds which isolate from different natural sources such as plants, animals, microbes, insects, plant pathogens, and endophytes and marine. These are known as secondary metabolites since they are formed due to the enzymatic resections of primary metabolites (amino acids, sugars, vitamins, etc.). Terpenes belong to the biggest

**Figure 1.** Classification of terpenes.

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

class of secondary metabolites and basically consist of five carbon isoprene units which are assembled to each other (many isoprene units) by thousands of ways. Terpenes are simple hydrocarbons, while terpenoids are modified class of terpenes with different functional groups and oxidized methyl group moved or removed at various positions. Terpenoids are divided into monoterpenes, sesquiterpenes, diterpenes, sesterpenes, and triterpenes depending on its carbon units (**Figure 1**). Most of the terpenoids with the variation in their structures are biologically active and are used worldwide for the treatment of many diseases. Many terpenoids inhibited different human cancer cells and are used as anticancer drugs such as Taxol and its derivatives. Many flavorings and nice fragrances are consisting on terpenes because of its nice aroma. Terpenes and its derivatives are used as antimalarial drugs such as artemisinin and related compounds. Meanwhile, terpenoids play a diverse role in the field of foods, drugs, cosmetics, hormones, vitamins, and so on. This chapter provides introduction and information on the bioactive terpenes isolated currently from different natural sources.

compound. The compounds belong to this class usually have strong aroma and odor and are used in many pharmaceutical companies. Mixture of different monoterpene-based oils is used as fragrances for making perfumes and in other cosmetics. Most of the monoterpenes are active biologically with strong antibacterial activities. Several studies have shown *in vitro* and *in vivo* antitumor activity of many essential oils obtained from plants. The antitumor activity of essential oils of many species has been related to the presence of monoterpenes in their composition [1]. Herein, we are discussing some of the recently published active mono-

Sesquiterpenes are the class of secondary metabolites consisting of three isoprene units (C15H24) and found in linear, cyclic, bicyclic, and tricyclic forms. Sesquiterpenes are also found in the form of lactone ring (**Table 2**). Many of the latex in latex-producing plants contain sesquiterpene, and these are potent antimicrobial and anti-insecticidal agent. Artemisinin, a sesquiterpene lactone, one of the most active compounds in *Artemisia annua* shoots and roots (**Figure 3**).

**Names Plant source Activity Ref.**

oxide production in BV-2 cells induced by lipopolysaccharide with IC50 values of 43.2

Introductory Chapter: Terpenes and Terpenoids http://dx.doi.org/10.5772/intechopen.79683 3

(0.97 μM) is several folds higher than that for other clinically used antidepressants using the same method. It could be used as a molecular scaffold for the development of more potent inhibitors with higher selectivity

against LPS-stimulated nitric oxide (NO) production in RAW 264.7 macrophage cells with IC50 values of 10.8, 12.6, and 11.7 μM,

anti-inflammatory activity of A appears to be mediated via suppression of an LPS-induced NF-κB pathway and downregulation of

These compounds were evaluated for their cytotoxicities against three renal carcinoma cell lines, ACHN, OS-RC-2, and 786-O cells, and it displayed activities with IC50 values of 0.89–8.2 μM. Further studies indicated that it arrested the cell cycle at the G0/G1 phase at a concentration of 1 μM and induced late apoptosis at a concentration of 2 μM after a

[3]

[4]

[5]

[6]

[7]

and 39.9 μM, respectively.

for the hα4β2 AChR.

*Artemisia freyniana* B, C, and G exhibited inhibitory effects

respectively.

MAPK activation.

72 h treatment of 786-O cells.

Arvestolides H and I *Artemisia vestita* H and I showed inhibitory effects on nitric

Drimenin Canelo tree *Drimys winteri* Potency for drimenin at the hα4β2 AChR

Chrysanthemulide A *Chrysanthemum indicum* Mechanistic study revealed that the potential

Marine-derived *Aspergillus* 

*ochraceus* fungus

terpenes (**Table 1**, **Figure 2**).

**3. Sesquiterpenes**

Artefreynic acid B, C,

14-*O*-Acetylinsulicolide A, 6β,9α-dihydroxy-14-pnitrobenzoylcinnamolide,

insulicolide A

and G
