Chemical composition of essential oils from German, Roman, and Chinese chamomile flowers and their biological activities against three economically important insects

Authors: ALI, ABBAS - University Of Mississippi; Tabanca, Nurhayat; RAMAN, VIJAYASANKAR - University Of Mississippi; AVONTO, CRISTINA - University Of Mississippi; Yang, Xiangbing; DEMIRCI, BETUL - Anadolu Universtiy; CHITTIBOYINA, AMAR - University Of Mississippi; KHAN, IKHLAS - University Of Mississippi

Submitted to: Records of Natural Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/13/2023
Publication Date: 1/30/2023
Citation: Ali, A., Tabanca, N., Raman, V., Avonto, C., Yang, X., Demirci, B., Chittiboyina, A.G., Khan, I.A. 2023. Chemical composition of essential oils from German, Roman, and Chinese chamomile flowers and their biological activities against three economically important insects. Records of Natural Products. 17(4): 595-614. https://doi.org/10.25135/rnp.378.2211.2627.
DOI: https://doi.org/10.25135/rnp.378.2211.2627

Interpretive Summary: Essential oils (EOs) are the primary source of bioactive natural products used to control insect pests and vectors of disease. Due to concerns about the toxicity of conventional insecticides in the environment and human health, as well as the increase in pesticide resistance, it is necessary to develop alternative, more environmentally sound control strategies. Therefore, ARS scientists in Miami, FL, in collaboration with scientists at the University of Mississippi (Oxford, MS) and Anadolu University (Eskisehir, Turkey) conducted research to identify novel and safe natural insecticides from the flowers of three species of chamomile commonly used in traditional medicine: German chamomile (Matricaria chamomilla), Roman chamomile (Chamaemelum nobile) and Juhua or Chinese chamomile (Chrysanthemum x morifolium). Gas chromatography-mass spectrometry (GC-MS) and multivariate statistical analysis were used to separate and identify marker compounds for EOs from different types of chamomile. Laboratory bioassays with Aedes aegypti demonstrated that German and Chinese chamomile EOs showed biting deterrence similar to DEET, the standard mosquito repellent. Digging bioassays showed that German chamomile EO was significantly more repellent than DEET against imported fire ants, Solenopsis invicta and S. richteri. All chamomile EOs were toxic against female Caribbean fruit fly, Anastrepha suspensa. These results demonstrate the strong potential of chamomile EOs for development of effective and safe new biopesticides for control of mosquitoes, fire ants, and Caribbean fruit flies.

Technical Abstract: In this study, the essential oils (EOs) of flowers from German chamomile (GCEOs 1-5) Matricaria chamomilla, Roman chamomile (RCEOs 1-2) Chamaemelum nobile, and Chinese chamomile (CCEO-1) or “Juhua” Chrysanthemum morifolium were characterized by GC-FID and GC-MS analysis. In laboratory bioassays, EOs were tested for biting deterrence/repellency against Aedes aegypti, hybrid imported fire ants and toxicity against Anastrepha suspensa. GCEOs 1-5 were characterized by the higher contents of alpha-bisabolol oxide A (43%-66%) and alpha-bisabolol oxide B (10%-16%). On the other hand, isobutyl angelate (16%-17%), 2-butenyl angelate (12%-13%), isoamyl tiglate (11%-12%), 3-methyl pentylangelate (8%-11%), and trans-pinocarveol (6%-7%) were dominant compounds of RCEOs 1 and 2. The CCEO-1 was rich in borneol (31%), ar-curcumene (12%), bornyl acetate (7%) and intermedeol (5%). Biting deterrence of GCEO 2 and 3, and CCEO-1 was similar to DEET whereas the activity of other chamomile EOs was lower than DEET. Pure compounds alpha-bisabolol and 1,6-dioxaspiro[4.4]non-3-en-2-one from German chamomiles showed biting deterrence similar to DEET against Ae. aegypti. Based on the sand removal data, repellency of German chamomile EO against hybrid imported fire ants was higher than DEET whereas the activity of Roman chamomile EO was lower than DEET. All essential oils, GCEO-4, RCEO-2, and CCEO-1 were toxic against female A. suspensa. Further research, through intensive in vivo bioassays, is needed to explore the potential of these natural products in integrated pest management strategies.