Constituents And Bioactivity Of Volatile Oil From Chenopodium Ambrosioides L.

The volatile oil of many plants has the antibioticaction, sterilization and desinsection activities. Due to the wide concern on green chemicals and pesticides in ten years or so, botanical chemicals, especially the research of plant volatile oil has become into one of the hotspots in the subjects of modern biology and Chinese traditional medicine.The volatile oil of Chenopodium ambrosioides L. has anticancer, expelling wind and removing damness, expelling parasite and antibioticaction activities. Many researchers in the world have studied the volatile oil of C. ambrosioides, but most of the studies focus on the chemical constituents, desinsection and seed germination. The main deficiencies is different researcher use different separation and identification conditions, so that the main chemical constituents and their contents are different for different habitats and there is only a few researches about antibiotic action and restraint to botanical pathogen. So this study used the uniform extraction and identification conditions and methods, built the standard fingerprints of C. ambrosioides and analyzed the chemical constituents and their contents of C. ambrosioides for 12 habitats in 9 provinces of China. This research will provide the scientific basis for the quality control of C. ambrosioides and have important effect on the improving the quality of Chinese traditional medicine and its modernization. Based on the fingerprint of C. ambrosioides, this thesis researched the antibioticaction of 15 standard strains for skin and instrument sterilization and the antibacterial activity of 10 common botanical pathogens. All of the results will produce important effect on the development and utilization of C. ambrosioides to manufacture natural sterilizing products, natural medicine and pesticides. The main conclusion as follow:1. Based on the uniform extraction and identification conditions and methods, this research built the standard fingerprints of C. ambrosioides for the 12 habitats in 9 provinces of China. The GC analysis condition of the fingerprint has the advantage of very good separating effect, precision, repeatability and stability; therefore the fingerprints can be used as the standard and scientific evidence for the quality control of C. ambrosioides.2. The chemical constituents of the C. ambrosioides volatile oil in 12 habitats are similar, and they areα-terpinene, P-cymene, ascaridole and bornylene, the content of the chemical constituents is different in different habitats. All of the main chemical constituents have the menthane skeleton and they compose more than 90% of the total volatile oil. The constituents whose relative content is over 1% normally less than 5 kinds3. The quality of C. ambrosioides volatile oil was affected by the water and fertility condition in cultivate, time of sampling, plant parts of sampling, storage time and the extraction time of volatile oil. Among the different water treatments, the highest yield of volatile oil was got by the treatment with soil relative water content 40%. The yields of volatile oil are all obviously increased by the five kinds of micro fertilizer treatments, and the highest one was got by the treatment with more Zn and Mn fertilizers. There are significant differences between the yields of oil from different plant parts, the highest yield was got from the seed, the lowest was got from the stem and the oil yield from the leaf of C. ambrosioides was between the former two parts. The main chemical constituents of volatile oil from the three parts are basically similar, but the contents of them are different. Among different growth period, the lowest volatile oil yield was got in seedling period, and the yield of volatile oil was increasing with the growth of C. ambrosioides, the highest value appeared at Ripe stage, then sharply decrease.Storage time can affect the yield of volatile oil. But yield increased with the extending of storage time within 15 days, and then it decreased from 15 to 30 days. As a whole, the yield doesn't change very much during 30 days.In a short word, the best collection period for C. ambrosioides is ripe period, the best part to collect is the part aboveground with fruit, the best storage time is 15 days after collection, and the quality and quantity of the volatile oil of C. ambrosioides is best after 1 h extraction with vapor distillation.4. The volatile oil from C. ambrosioides has extensive effect of antibioticaction and sterilization. It has inhibiting effect to the 14 experimental strains except Bacillus aeruginosus among the 15 standard strains for skin and instrument sterilization. The inhibitory concentration of volatile oil from C. ambrosioides in vitro is low, and the lowest value are 1.95-62.5μL /mL and the lowest bactericidal concentration are 7.8-250μL /mL to different strains. Therefore, volatile oil from C. ambrosioides has good inhibiting effect, and it is one of the high-value medicinal herbs to exploit.The result of acute toxicity experiment showed that toxic dose of intragastric administration of volatile oil from C. ambrosioides to small mouse is high, the half-lethal dose (LD₅₀) is 1183μL /kg,this result supposed that the LD₅₀ for human being of volatile oil from C. ambrosioides should be 9.18 mL /70kg.In this thesis, we use the growth rate method identified the inhibition effect of volatile oil from C. ambrosioides to 10 botanical pathogen. The result showed the volatile oil from C. ambrosioides has inhibiting activities to 10 botanical pathogen except Sclerotinia sclerotiorum. The inhibiting acitivity to Rhizoctonia cerealis is strongest among the 10 botanical pathogen, and its inhibiting ratio reached 100% at 0.5 uL/mL in 9 days. The inhibiting activity to Alternaria solani and Phytophthora capsici is stonger than to Gaeumannomyces graminis, Fusarium graminearum and Fusarium oxysporum (scho) f.sp.cucumbrum. The inhibiting ratio of the former two at 0.5 uL/mL in 7 days was 88.9% and 74.5%, respectively. And the volatile oil from C. ambrosioides has no inhibiting activity to Botrytis cirerea, Glomerella cingulata, Colletrichum orbiculare, and Sclerotinia sclerotiorum. The inhibiting rates of them are all under 35%.The inhibiting effect increased with the increasing concentration of volatile oil from C. ambrosioides, meanwhile, the inhibiting capability decreased with the lasting of culture time. The volatile oil from C. ambrosioides has common, high efficient and lasting inhibiting activity to lots of botanical pathogen and has a promising application for pesticide.The volatile oil from C. ambrosioides has fumigation effect on insects, and the effective fumigating dose of Mythimna separata and Culex pipien is less than 10 ppm.The median lethal concentration (LC₅₀) of volatile oil from C. ambrosioides is only 2.11μL/L to M. separata after 30 min fumigation, and it decrease sharply to around half (1.07μL/L) after 75 min fumigation. The LT₅₀ of LC₉₅ dose treatment to M. separata is 20.04 min. The result indicate that the contact toxicity activity of volatile oil to M. separata increase with the contact time lasting, meanwhile, the death rate increase and the lethal time obviously decrease with the increasing of volatile oil concentration. The efficiency of fumigation is higher than that of contact toxicity. The median lethal concentration (LC₅₀) of volatile oil from C. ambrosioides to C. pipien is 1.59μL/L after 2 h fumigation. The median knockdown time (KT₅₀) of LC₉₅ dose treatment to C. pipien is 8.71 min. These result indicated the volatile oil from C. ambrosioides has high speed and efficient of fumigation activity as well, but the avoidance time of it is only 2 h, meanwhile, it is irritating to skin and has toxicity to human being, therefore it is unsuited to using as repellent for mosquito and soothing lotion to human being.