Essential Oil Chemotypes of Four Vietnamese Curcuma Species Cultivated in North Alabama

Curcuma (turmeric) species are important culinary and medicinal plants, and the essential oils of Curcuma rhizomes have demonstrated promising pharmacological properties. The essential oils (EOs) of Curcuma species possess a wide variety of pharmacological properties, including anti-inflammatory, anticancerous, antiproliferative, hypocholesterolemic, antidiabetic, antirheumatic, hypotensive, antioxidant, antimicrobial, antiviral, antithrombotic, antityrosinase, and cyclooxygenase-1 (COX-1) inhibitory activities, among others. Curcuma oils are also known to enhance immune function, promote blood circulation, accelerate toxin elimination, and stimulate digestion. C. longa (turmeric) and C. zedoaria (zedoary) are the most extensively studied species of Curcuma due to their high commercial value. There is some interest in expanding the cultivation of Curcuma species to the southern regions in North America where the climate is favorable. The purpose of this work was to examine the rhizome essential oil composition of four species of Curcuma (C. aromatica, C. caesia, C. longa, C. zanthorrhiza) that were obtained from Vietnam and cultivated in North Alabama. The rhizome essential oils were obtained by hydrodistillation and analyzed by gas chromatographic techniques. The essential oils of C. aromatica were dominated by curzerenone (14.7–18.6%), germacrone (10.7–14.7%), 1,8-cineole (5.2–11.7%), and an unidentified component (8.7–11.0%). The major components in C. longa rhizome oil were ar-turmerone (8.3–36.1%), α-turmerone (12.7–15.2%), β-turmerone (5.0–15.4%), α-zingiberene (4.6–13.9%), and β-sesquiphellandrene (4.6–10.0%). The essential oils of C. caesia and C. zanthorrhiza were rich in curzerenone, curdione, and germacrone. These adapted turmeric varieties in North Alabama have potential use for medical purposes and medicinal plant oil market demands in the U.S.