Center for Advanced Chemistry, Institute of Research and Development, Duy Tan University, 03 Quang Trung, Da Nang, 50000, Vietnam.
Department of Pharmacy, Duy Tan University, 03 Quang Trung, Da Nang, 50000, Vietnam.
Chem Biodivers. 2023 Mar;20(3):e202200210. doi: 10.1002/cbdv.202200210. Epub 2023 Feb 16.
There is an ongoing interest to identify alternative pesticidal agents to avoid the chronic problems associated with synthetic pesticides. Essential oils have shown promise as botanical pest control agents. In the present study, the essential oils of four members of the Lamiaceae (Callicarpa candicans, C. erioclona, C. macrophylla, and Karomia fragrans; Vietnamese names: Nàng nàng, Tu châu lông mem, Tu châu lá to and Cà diện, respectively), obtained from wild populations in Vietnam, have been obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry. The essential oils were formulated into microemulsions and the essential oils and their microemulsions were screened for mosquito larvicidal activity against Aedes aegypti, Aedes albopictus, Culex quinquefasciatus, and for molluscicidal activity against Pomacea canaliculata. Atractylone and (E)-caryophyllene dominated the volatiles of C. candicans (CCEO) and C. erioclona (CEEO), while the major component in C. macrophylla (CMEO) and K. fragrans (KFEO) was (E)-caryophyllene. The essential oils and microemulsions of both C. candicans and C. erioclona exhibited excellent larvicidal activity against all three mosquito species (Ae. aegypti, Ae. albopictus, and Cx. quinquefasciatus) with LC values <10 μg/mL. Additionally, the larvicidal activity of the microemulsions were significantly improved compared with their free essential oils, especially for C. candicans and C. erioclona. All four essential oils and their microemulsions showed excellent molluscicidal activity with LC <10 μg/mL. In most cases, the essential oils and microemulsions showed greater pesticidal activity against target organisms than the non-target freshwater fish, Oreochromis niloticus. The in silico studies on physicochemical and ADMET properties of the major components in the studied essential oils were also investigated and most of the compounds possessed a favorable ADMET profile. Computational modeling studies of the studied compounds demonstrated a favorable binding interaction with the mosquito odorant-binding protein target and support atractylone, β-selinene, and caryophyllene oxide as potential inhibitors. Based on the observed pesticidal activities of the essential oils and their microemulsions, the Callicarpa species and K. fragrans should be considered for potential cultivation and further exploration as botanical pesticidal agents.
人们一直有兴趣寻找替代农药的方法，以避免与合成农药相关的慢性问题。精油已被证明是有前途的植物性害虫防治剂。在本研究中，从越南野生种群中获得了唇形科（Callicarpa candicans、C. erioclona、C. macrophylla 和 Karomia fragrans；越南名称：Nàng nàng、Tu châu lông mem、Tu châu lá to 和 Cà diện）的精油，通过水蒸馏法提取，并通过气相色谱-质谱法进行分析。将精油制成微乳液，并对其进行蚊虫幼虫活性筛选，测试对象为埃及伊蚊、白纹伊蚊、致倦库蚊，同时还对其进行了 molluscicidal 活性筛选，测试对象为福寿螺。苍术酮和（E）-石竹烯是 C. candicans（CCEO）和 C. erioclona（CEEO）的主要挥发性成分，而 C. macrophylla（CMEO）和 K. fragrans（KFEO）的主要成分是（E）-石竹烯。精油和微乳液对三种蚊子（埃及伊蚊、白纹伊蚊和致倦库蚊）都表现出极好的幼虫致死活性，LC 值均小于 10μg/mL。此外，与游离精油相比，微乳液的幼虫致死活性显著提高，特别是对 C. candicans 和 C. erioclona。四种精油及其微乳液对福寿螺均表现出优异的杀螺活性，LC 值均小于 10μg/mL。在大多数情况下，精油及其微乳液对目标生物的杀虫活性大于非目标淡水鱼类奥利亚罗非鱼。还对研究中精油主要成分的理化性质和 ADMET 特性进行了计算机模拟研究，大多数化合物具有良好的 ADMET 特性。对研究化合物的计算机建模研究表明，它们与蚊子气味结合蛋白靶标具有良好的结合相互作用，苍术酮、β-榄香烯和石竹烯氧化物可作为潜在的抑制剂。基于精油及其微乳液的观察到的杀虫活性，应该考虑将假马齿苋属和 K. fragrans 作为植物性杀虫剂进行潜在的种植和进一步探索。
