## 4 Industrial Applications of Terpenoids
### Pharmaceutical and Medical Industry  
Terpenoids are widely used in clinical medicine as new anticancer drugs in the pharmaceutical industry since they possess antitumor, anti-inflammatory, and anticancer properties. Given these properties, terpenoids have also shown the potential to be used as new therapeutic agents to treat or prevent malaria, inflammation, pain, cardiovascular diseases, and other diseases [PERSON] et al. (2018).  
Global Cancer Data 2020 estimates that there were 19.3 million new instances of cancer and 10.0 million cancer deaths globally this year, making the current cancer rates a serious global public health issue [PERSON] et al. (2018). The pharmaceutical industry has placed a significant emphasis on research into active anticancer and cancer prevention components in its quest to find treatments for malignant tumors. They provide new active molecules for the development of drugs, such as taxol, elemene, selenodiene, and limonene, which exert their antitumor and anticancer activities through different or novel mechanisms [PERSON] et al. (2018). Taxol, a natural direpenoid, was discovered and refined from Taxus plants and appears as a novel class of antitumor medications and is used in the treatment of advanced types of cancer (e.g., ovarian, breast, and lung cancer) [PERSON] et al. (2018). Elemene, a newly developed and widely used anticancer medication produced from Curcumin wenyujin, has very mild side effects in the treatment of lung cancer, liver cancer, nasopharyngeal carcinoma, and brain tumors and does not include harmful epoxy, nitro, onion ring, or benzene ring groups [159]. This is a sesquiterpene compound with low toxicity, a broad spectrum, and fewer negative effects than radiation and chemotherapy, while improving the effectiveness of treating solid cancers. Other studies have shown that elemene has a sizable inhibitory impact on cancer cells and that it inhibits lipid-induced inflammatory pathways in heart failure [160]. Regarding limonene, there are two optically active forms: l-limonene, and D-limonene. D-limonene is the most common form and has the strongest pharmacological action. It is used in the field of medicine for the treatment of cholecystitis, a condition characterized by inflammation of the gallbladder [161]. Moreover, the anti-inflammatory and antitumor properties of limonene are primarily caused by the inhibition of pro-inflammatory molecules that are linked to cancer [162]. Pinene has anti-inflammatory and antiapoptotic properties and has been found to be effective in the treatment of Alzheimer's disease, Parkinson's disease, and other neurodegenerative diseases [163]. On the other hand, artemisinin, a sesquiterpene lactone, has been found to have antimalarial functions; consequently, artemisinin derivatives have been used as a therapeutic agent for malaria since they contain endoperoxide bridges, which are essential for antimalarial activity [164]. This sesquiterpene lactone destroys malaria parasites by inhibiting the proteasome and damaging proteins [165].  
However, the application of terpenoids in the pharmaceutical and medicinal industries faces challenges such as complex sources, low yield, and low purity. The production of terpenoids by microorganisms has drawn more interest recently because of the limits of natural sources. Large-scale fermentation of terpenoids using engineered microbes promises a better output, batch-to-batch uniformity, reduced cost, and more sustainability. Moreover, the safety and pharmacological activity of terpenoids in medicine have always been a focus and a difficult problem to solve. Further exploration of the mechanisms of action of terpenoids in drugs should provide a better grasp of their pharmacological effects. The clinically evident method of therapeutic activity of many terpenoids has not yet been clarified, and further research is needed to develop new medication substances [166].