Identification and Characterization of Bio-pesticides from Acorus spp. Essential Oil
Bioprospecting in natural products from plants used in Traditional Chinese Medicine have shown a 20 times increase in detection of biological activity when compared to many other discovery methods. Since registration of new GRAS (generally regarded as safe) agrochemical agents for plant disease and animal insect control is significantly easier, natural compounds from TCM plants are of great interest to the US Department of Agriculture. Acorus tatarinowii Schott. and Acorus calamus Linn. are commonly used as traditional Chinese medicine, they are used treat epilepsy, Alzheimer's disease, and depression. The essential oils from two Acorus species were obtained by hydrodistillation and their chemical profiles were identified using over-pressured layer chromatography and gas chromatography-mass spectrometry. The two Acorus species were evaluated for antifungal and mosquito deterrent activity. Preliminary testing showed them to be active. Several isolated compounds were evaluated by bioautography against plant pathogens Colletotrichum acutatum, C. fragariae and C. gloeosporioides and shown to have antifungal activity. Bioassay guided fractionation is also being conducted to separate, identify, and characterize compounds with adult mosquito repellent, biting deterrent, larvicidal and adult toxicant activity. Further in-depth insect studies will take place as appropriate, and further purification and structural elucidation to allow for detailed biochemical and physiological studies are under the way. Discovery of new agrochemical agents with low mammalian and environmental toxicity that will help guarantee food safety, sustainability of U.S., Chinese, and world agriculture, and ensure a safe and healthy environment. Acknowledgements: Funding support came from the Aid program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province (Grant No.2010/212) and support from Hunan Administration of Foreign Experts Affairs (Grant No.2012/26).