The Story of the Pinene Isomers

Befitting the wintry scene canvasing much of the landscape as we near the new year, this story regards alpha­– and beta-pinene. Both monoterpenes provide the characteristic fragrance of conifer trees like those decorating houses both in fragrance and illumination. These molecules can be found in other plants like sage, basil, dill, rosemary, mace, juniper and black pepper. Alpha-pinene has been quantified in plants including frankincense and ginger. Beta-pinene has been measured in plants including hyssop, cumin, and Aztec marigold. Of course, given their similarities, they are common to many more plants.

alpha-Pinene is said to be the most widely encountered monoterpene in nature. [1] It’s been studied for potential expectorant and bronchodilator properties [2,3]. Alpha-pinene offers anti-inflammatory properties [4]; it also demonstrated anti-cancer activity against human liver cancer cell lines by preventing the tumor cells from proliferating [5].

One of the most intriguing properties of alpha-pinene has been the neuroprotective potential from memory disorders like dementia. [6] This process comes from alpha-pinene’s ability to inhibit the enzyme acetylcholinesterase, which breaks down the neurotransmitter acetylcholine into choline and acetic acid. This occurs to get rid of spent acetylcholine once its mission has concluded. But, by preventing its degradation, the neurotransmitter remains useful. This mechanism has been studied in treating neurodegenerative disorders. [6,7]

In an interview with Ethan Russo, MD, Russo commented that “alpha-pinene can effectively reduce or eliminate the short-term memory impairment classically induced by THC [delta-9-tetrahydrocannabinol].” [8] Perhaps, then, rather expectedly, it would come as no surprise that the cannabis cultivar named Amnesia had lower alpha-pinene content when compared to White Widow. [9] Given potential reductions in short-term memory deficiencies, its scarcity in Amnesia may play a role in the amnesic effects.

The oil extracted from Mexican bay leaves contained several terpenes like beta-pinene, alpha-pinene, linalool, limonene, and eucalyptol. [10] Beta-Pinene and linalool demonstrated anti-depressive properties in mice treated with the oil, while α-pinene, limonene, and eucalyptol did not. These researchers showed that beta-pinene and linalool interact with the monoaminergic system. [11] Monoaminergic substances work by interacting with monoamine neurotransmitters like serotonin and dopamine. The elevation of these neurotransmitters is effective in treating depression.

The pinene isomers adorn the atmosphere with a wonderfully invigorating, pungent fragrance that stimulates alertness whether they’re incorporated into one’s wintry décor or not. These monoterpenes have shown promise for helping Alzheimer’s disease patients retain cognitive abilities, making them valuable for amplified scientific research. So, this holiday season, you can help spread the good word by regaling your loved ones with campfire stories of apical dominance in conifers while airborne alpha– and beta-pinene molecules effortlessly augment the organoleptic scene.

References

1. Noma Y, Asakawa Y. “Biotransformation of Monoterpenoids by Microorganisms, Insects, and Mammals.” Handbook of Essential Oils: Science, Technology, and Applications, edited by KHC Baser and G Buchbauer, CRC Press, 2010, pp. 585–736. [journal impact factor = N/A; cited by 17 (ResearchGate)]
2. Sheppard, E. and Boyd, E. “Lemon Oil as an Expectorant Inhalant,” Pharmacological Research Communications, vol. 2, no. 1, 1970, pp. 1-16. [journal impact factor = 5.57; cited by 3 (ResearchGate)]
3. Falk-Filipsson, A., et al. “Uptake, Distribution and Elimination of alpha-Pinene in Man after Exposure by Inhalation.” Scand J Work Environ Health, vol.16, no.5, 1990, pp. 372–378. [journal impact factor = 3.775; cited by 97 (ResearchGate)]
4. Rufino, A., et al. “Anti-Inflammatory and Chondroprotective Activity of (+)-α-Pinene: Structural and Enantiomeric Selectivity.” J. Nat. Prod., vol.77, no.2, 2014, pp. 264–269. [journal impact factor = 4.257; cited by 67 (ResearchGate)]
5. Chen, W., et al. “Anti-Tumor Effect of α-Pinene on Human Hepatoma Cell Lines Through Inducing G2/M Cell Cycle Arrest.” Journal of Pharmacological Sciences, vol.127, 2015, pp. 332-338. [journal impact factor = 2.439; cited by 54 (ResearchGate)]
6. Lee, G., et al. “Amelioration of Scopolamine-Induced Learning and Memory Impairment by α-Pinene in C57BL/6 Mice.” Evidence-Based Complementary and Alternative Medicine, vol.2017, ID 4926815. [journal impact factor = 2.064; cited by 11 (ResearchGate)]
7. Orhan, I., et al. “Inhibitory Effect of Turkish Rosmarinus officinalis L. on Acetylcholinesterase and Butyrylcholinesterase Enzymes.” Food Chemistry, vol.108, no.2, pp. 663-668. [journal impact factor = 5.399; cited by 111 (ResearchGate)]
8. Piomelli, D. and Russo, E. “The Cannabis sativa Versus Cannabis indica Debate: An Interview with Ethan Russo, MD.” Cannabis and Cannabinoid Research, vol.1, no.1, 2016, pp. 44–46. [journal impact factor = N/A; cited by 39 (ResearchGate)]
9. Hazekamp, A. and Fischedick, J. “Cannabis – From Cultivar to Chemovar,” Drug Testing and Analysis, vol. 4, no. 7-8, 2012, pp. 660-667. [journal impact factor = 2.799; cited by 70 (ResearchGate)]
10. Guzmán-Gutiérrez, S., et al. “Antidepressant Activity of Litsea glaucescens Essential Oil: Identification of β-Pinene and Linalool as Active Principles.” Journal of Ethnopharmacology, vol.143, no.2, 2012, pp. 673-679. [journal impact factor = 3.115; cited by 61 (ResearchGate)]
11. Guzmán-Gutiérrez, S., et al. “Linalool and β-Pinene Exert their Antidepressant-like Activity Through the Monoaminergic Pathway.” Life Sciences, vol.128, 2015, pp. 24-29. [journal impact factor = 3.448; cited by 40 (ResearchGate)]

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