Elettaria cardamomum leaves, an underutilized resource: chemical profile of its essential oil and insecticidal activity.

Elettaria cardamomum is known as the 'Queen of spices'; its leaf essential oil (EO) is least investigated and barely utilized. Here we report the chemical composition of E. cardamomum leaf EOs collected from five locations in the southern Western Ghats in India. EOs of fresh and dry capsules were also analyzed for comparison of their chemical profiles. The major constituents in cardamom leaf EOs were β-pinene (35.6–51.9%) and coronarin E (17.7–34.2%). In fumigant toxicity assays against two stored product pests, lowest LC50 against Tribolium castaneum was recorded in EO of fresh capsules (124.05 µL/L), followed by dry capsules (LC50 128.21 µL/L) and leaves (LC50 148.00 µL/L); LC50s of fresh, dry capsule and leaf EOs against Sitophilus oryzae were 30.24, 35.33 and 89.42 µL/L, respectively. This study demonstrates cardamom leaves as a source of untapped bioactive principles which can be viably utilized for the production of botanical pesticides. [ABSTRACT FROM AUTHOR]