# _Cannabis sativa_ L. as a Natural Drug Meeting the Criteria of a Multitarget Approach to Treatment
## 3 Chemical Composition
### 3.2. Tepenes  
Another biologically active group of compounds found in _Cannabis sativa_ L. are terpenes. There are over 150 different terpenes in _Cannabis_. Most of them are not unique for _Cannabis_ sp. ; they occur in many plants from various families. Terpenes are synthesized like cannabinoids in trichomes. The mean contents of terpenes in _C. sativa_ L. vary from 0.5-3.5%; they also can be identified in smoke and fumes generated during smoking or vaporization [60]. There seems to be a close relationship between the plant's cannabinoid and terpene contents [45]. Being the main secondary metabolites besides cannabinoids, they could be used as chemotaxonomic markers [42], but they were not taken into account in the classification systems used so far [76]. Terpenes are classified according to the number of five-carbon fragments known as isoprene units. Those found in _Cannabis_ include ten-carbon monoterpenes, fifteen-carbon sesquiterpenes, and thirty-carbon triterpenes (Figure 5). The mono- and sesquiterpenes shown in Figure 5 have been found in parts of the plant, such as the leaves, roots, and flowers. Among monoterpenes, we can distinguish the predominant constituents of the volatile terpene fraction: D-limonene, linalool, \(\beta\)-myrcene, terpinolene, and \(\alpha\)- and \(\beta\)-pinene. Sesquiterpenes (Figure 5), including \(\beta\)-careophyllene and \(\alpha\)-humulene, are found in significant amounts in _Cannabis_ extracts. Triterpenes (Figure 5) are found in _Cannabis_ roots. These are friedelin and epifriedeland, as well as \(\beta\)-amyrin in _Cannabis_ fibers. Cycloartenol, dammaradienol, and \(\beta\)-amyrin were detected in hempseed oil [42]. There are two main biosynthetic pathways for plant-derived terpen, as shown in Figure 6. The first is the plastidic methylerythitol phosphate (MEP) pathway responsible for the production of monoterpenes, diterpenes, and tetraterpenes. The second, the cytosolic mexulonic acid (MVA) pathway, is involved in the synthesis of sesquiterpenes and triterpenenes. The initial substrates of the pathways are pyruvate and acetyl-CoA. They are converted to isopentenyl diphosphate (IPP) and then isomerized to dimethylallyl diphosphate (DMAPP). Within the MEP pathway, the condensation of IPP and DMAPP occurs and the formation of GPP, which is a precursor to monoterpenes. In the MVA pathway, two IPP molecules and one DMAPP are combined, resulting in the formation of famesyl diphosphate (FPP), which is sesquiterpenes' and triterpenes' precursor [42]. Studies have been conducted comparing the terpene profile of _Cannabis sativa_ ssp. _indica_ var. _indica_ (so-called _C. indicia_) and _Cannabis_ ssp. _sativa_ var. _sativa_ (so-called _C. sativa_), in order to distinguish them according to their terpene profiles. In plants of the former variety, higher amounts of \(\beta\)-myrceene and limonene or \(\alpha\)-pinene were found. On the other hand, the terpene profiles of the _Cannabis sativa_ ssp. _sativa_ var. _sativa_ (called _C. sativa_) proved to be more complex. Some plants were more abundant in \(\alpha\)-terpinolene or \(\alpha\)-pinene, while, in others, \(\beta\)-myrceene, accompanied by \(\alpha\)-terpinolene or trans-\(\beta\)-ocimene, was predominant [77]. The different terpene profiles have an impact on the odor and the taste of Cannabis [60; 76]. The smell of _Cannabis sativa_ ssp. _sativa_ var. _sativa_ (so-called _C. sativa_) is described as herbal or sweet, while the aroma of _Cannabis sativa_ ssp. _indica_ var. _indica_ (so-called _C. indica_) is defined as irritating and smelly [48]. According to the fact that terpene compounds are the source of the plant's characteristic smell, some of them, such as \(\beta\)-caryophyllene and caryophyllene oxide, are used to train dogs to enable the detection of marijuana or hashish [41]. Some terpen are found only in the fresh plant due to their volatile nature--for example, \(\alpha\)-pinene and limonene [41].