**4. Future**

## **4.1 Expect role—medical Marijuana**

Marijuana, *Cannabis sativa*, a plant frequently referred to as cannabis or pot, is a psychoactive, medicinal drug plant (**Figure 4(1)**). The plant tissues synthesize cannabinoid acids that under warm temperatures are converted to two major constituents: tetrahydrocannabinol, abbreviated as THC (**Figure 4(2)**), and cannabidiol, abbreviated as CBD (**Figure 4(3)**). THC is an intoxicating plant constituent that activates a brain receptor that initiates the intoxication and activates a pleasurable reward system in the brain. CBD, a nonpsychoactive constituent in marijuana, is considered to have therapeutic applications, especially for seizures.

#### **Figure 4.**

*(1) Marijuana (Cannabis sativa), (2) diagram of THC, tetrahydrocannabinol, (3) diagram of CBD, cannabidiol.* 

#### **4.2 Development of new drug, progress of research**

Pharmaceutical industry is growing every year, especially the industry in United States added an estimated \$790 billion to the economy in 2014 [10]. Organic chemical of plant materials will give a hint to create a new drug including the level of family, plant species, and cultivars. Today, at least 120 distinct chemical substances derived from plants are considered as important drugs [9]. The structure of compound and constituent shows unique medicinal action (**Table 4**) [11] and knowledge and practices of traditional medicinal plants indicated the appropriate uses for the symptom. The information will become a signpost to develop a new drug. Traditional medicinal plants and ethnobotany have possibility to be great resources, such as artemisinin (discovered in *Artemisia annua*) and quinine (from *Cinchona* 


#### **Table 4.**

*Compound groups included in essential oils and actions of the compound groups.* 

 *officinalis*) [12]. Once single compound was identified, extraction or synthesis was possible, which is almost full-drug stage. After clinical trial indicated effectiveness, the compound will be a new drug [13].
