# Antitumor Effects of _Cannabis sativa_ Bioactive Compounds on Colorectal Carcinogenesis
## 2 Bioactive Compounds of _Cannabis sativa_
### Terpenes  
Terpenes, characterized by multiple five-carbon isoprene units linked together to form a chain of hydrocarbons, comprise the second-largest class of plant constituents (120 identified so far). These secondary metabolites are synthesized via the isoprenoid biosynthesis metabolic pathway (Figure 2). Isopentenyl pyrophosphate (IPP) and its isomer dimethylallyl pyrophosphate (DMAPP), which are generated through the mevalonic acid (MEV) or methylerythriol phosphate (MEP) pathway, serve as the precursor molecules for this pathway. Afterward, a series of enzyme-catalyzed processes transform the IPP and DMAPP into several terpene precursors, including GPP, famresyl pyrophosphate (FPP), and geranylgeranyl pyrophosphate (GGPP). GPP is responsible for the production of terpene molecules, which are then used in the production of cannabinoids. Different terpene synthases can further modify these precursors to produce a variety of monoterpenes, sesquiterpenes, and diterpenes [38; 39]. In general, these compounds are synthesized in different parts of the plant, such as the flowers, roots, leaves, and trichomes, with variable levels, which depend on abiotic and biotic factors [19]. Particularly in _C. sativa_, [PERSON] and coworkers found that terpen may vary between 0.001 and 14.8 mg/g of the dry weight of the plant [39] and are in general rich in mono- and sesquiterpenes [34]. Monoterpenes, structurally characterized by a skeleton with two molecules of isoprene, are more volatile and contribute to the flavor and aroma of the plant, while sesquiterpenes (structure containing three molecules of isoprene) are more stable and contribute to the therapeutical benefits of the plant [40]. The monoterpene \(\beta\)-myrcene and the sesquiterpenes \(\beta\)-careyophyllene and \(\alpha\)-humulene have been identified in most cannabis species, including _C. sativa_. Other typical terpen synthesized by this species include \(\alpha\)-pinene and limonene, among others (Figure 3) [41]. In addition, terpenoids (i.e., oxygenated terpen) such as linalool, \(\alpha\)-terpineol, guaiol, \(\alpha\)- and \(\beta\)-bisabolol are often found in _C. sativa_[42]. Moreover, in a study by [PERSON], among six genotypes of _C. sativa_, four were found to have pinocarveol in large amounts. Additionally, one of the genotypes contained significantly higher concentrations of the major terpen (limonene, linalool, fenchol, and \(\alpha\)-terpineol) when compared to the other genotypes. As a \begin{table}
\begin{tabular}{c c c} \hline \hline
**Cannabinoids** & **Pharmacological Effects** & **Refs.** \\ \hline CBD & Antiepileptic, antioxidant, anti-inflammatory, antienetic, & [26; 32; 33; 34; 35] \\  & immunosuppressive, antipsychotic, neuroprotective, anticancer & \\ \(\Delta^{9}\)-THC & Antioxidant, antipurritic, anti-inflammatory, neuroprotective, & [33; 34] \\  & analgesic, anticancer, antiausea & \\  & Antibacterial, antifungal, anti-inflammatory, prevents cell & \\ CBG & proliferation, anticancer, antidepressant, & [26; 36; 37] \\  & antihypertensive, analgesic & \\ CBC & Anti-inflammatory, analgesic & [32; 34] \\  & Scalable, anticonvulsant, antiinflammatory, & [32; 33; 34] \\  & antibiotic, anticancer & \\ THCV & Weight loss, anticonvulsant, antihyperalgesia, & \\  & anti-inflammatory, anticancer & \\ CBDV & Inhibits endocannabinoid degradation, antinausea, & \\  & anticonvulsant, anticancer & \\ \hline CBC, cannabinoid; CBD, cannabinoid; CBDV, cannabinoid; CBDV, cannabinoid; CBG, cannabinoid; CBN, cannabinoid; \(\Delta^{9}\)-THC, \(\Delta^{9}\)-tetrahydrocannabinol; THCV, tetrahydrorocannabivarin. & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Pharmacological effects associated with the major cannabinoids identified in _C. sativa_. result, depending on the substances of interest, the genotype selected, as well as the type of extraction, should always be adjusted.