Studies On Insecticidal And Miticidal Activities Of Chinese Traditional Medicine Turmeric Curcuma Longa And Its Action Mechanism

Curcuma longa L. is a plant of Indian origin commonly used in Asiatic cultures for several hundreds as a spice named turmeric. As the development of sci-technology, the function of turmeric had been beyond traditional medicine konown by human beings. The main component is curcumin, one of the active ingredients responsible for its biological activity. Curcumin is a major yellow pigment in turmeric (the ground rhizome of Curcuma longa Linn), which is widely used as a spice and coloring agent in several foods, such as curry, mustard and potato chips, as well as cosmetics and drugs. A wide range of biological and pharmacological activities of curcumin has been investigated. Curcumin is a potent inhibitor of mutagenesis and chemically induced carcinogenesis. It possesses many therapeutic properties including anti-inflammatory and anticancer activities. Curcumin is currently attracting strong attention due to its antioxidant potential as well as its relatively low toxicity to rodents. Curcuminoids also exhibited antioxidant activities in some in vitro lipid peroxidation systems and suppressed 12-Otetradecanoylphorbol 13-acetate-induced hydrogen peroxide production and oxidized DNA formation in the mouse epidermis. Curcumin is an inhibitor of neutrophil responses and superoxide generation in macrophages.The main miticide used in agriculture was mostly high effective and low toxicity compounds, the most of which were liable to degrade, however mcst of them were all nervous toxicity compound. There were a few documents concerned naught social effects of pollution botanical miticides and mostly focused on plant extracts, but there was no doucument mentioned turmeric till now. Based on a lot of bioassay jobs, turmeric was selected as research object. Through this study, one or more miticidal activity compounds were found in turmeric. And the fulfillment of all these jobs can help explore one botanical miticide or at least prepare for developing miticide. After 2 years study, the main results are as follows:1 The primary estimate of insecticidal and miticidal activities of turmericThe acarcidal bioactivities against Tetranychus cinnabarinus of hexane, benzene, ether, methanol sequential and parallel extracts from Chinese traditional medicine Curcuma longa were carried about in this paper. The results showed that at 1% concentration, treatment after 72h, the corrected mortality of hexane and benzene extract from C. longa against T. cinnabarinus was both 100%. Treatment after 72h, in the parallel extract, the LC50 of hexane, benzene, ether, methanol and water extract from C. longa was 0.7753,0.0993,0.9S55,0.7873 and 0.8384gL-l, respectively.The fumigation action of turmeric sequential extracts against Sitophilus zeamais was weak. Comparing with all extracts, the fumigation action of low polarity extracts against S. zeamais was stronger than the high polarity extracts. Among the sequential extracts of turmeric, the antifeedant action of hexane extracts was highest, the antifeedant rate was 100% and the corrected mortality after exposure 72h was 37.21%. The parallel extracts of turmeric all had high fumigation action against Liposcelis bostrychophila. The highest fumigation activity of methanol extract among all of parallel extracts was highest and corrected mortality after 24h was 91.53%. There was stronger contact action against Rhopalosiphum maidis in petroleum ether and benzene extracts.2. The extraction and separation of turmeric miticidal activity compounds and their miticide action evaluationThe curcumin crude extracts was separated by silica gel colum chromatography, and we received three group compounds, which was identified as curcumin, demethoxycurcumin and bisdemethoxycurcumin by TLC with standard sample. The contact action of adult, nymph and egg of T. cinnabarinus and the oviposit inhibition of adult mites of three curcuminoinds monomers curcumin (C), demethoxucurcumin (DMC) and bisdemethoxycurcumin (BDMC) were also conducted in this paper. The results showed mat the biological activities of contact action and oviposit inhibition of three monomers against T. cinnabarinus was BDMODMOC. All of which, the best of contact action against adult T. cinnabarinus among three monomers was BDMC and the LC₅0 at 24h and 72h was 1.1755 and 0.3789 g-L'1, respectively. The general tendency of contactaction against nymph T. cinnabarinus was same to adult, of which LC₅0 at 48h was 2.4091 g-L^-1.Turmerone and essential oils without turmerone showed higher contact action against T. cinnabarinus. From either LC50 or LC95, both 48h and 72h mortality concentration showed little difference. This illuminated that the toxicity followed with time showed little evidence and made out certain quick result. This also proved turmerone had both antifeedant effect and contact action against T. cinnabarinus. In this study we also testified there were other miticidal activity compounds besides turmerone.