Study On The Chemical Constituents And Its Fungicidal Activity Of Mikanaia Micrantha H.B.K

In order to apply and develope Mikania micrantha H.B.K, and provide theoretical basis to new types bioactival fungicide , we studied the chemical constituents and fungicidal activity of Mikania micrantha H.B.K,in this paper, and the main results as follows.1. The chemical constituents of the Mikania micrantha H.B.K. have been tested systematically by tube-test. It was found that the Mikania micrantha H.B.K contains steroids, terpenoids, flavonoids, anthraquinones, deoxidize sugar ,aminophenol, ester, coumarin, volatile oil and so on. It may contain saponins, alkaloids, hydroxybenzene.It does not contain phenylpropanoids.2. 90 kg whole Mikania micrantha H.B.K. sample was extracted with ethanol in the reaction cauldron ,and got 10 kg extract which was suspended in water, then was successively extracted with petroleum ether, chloroform, ethyl acetate and n-butanol, after concentrating we got petroleum extract (898.39g), chloroform extract (760.34g), acetic ether extract (666.76g), n-butanol extract (876.75g) .3. The fungicidal activity of Mikania micrantha H.B.K extract was tested in vitro and in vivo. Results showed that the chloroform extract had relatively strong growth inhibition to R. cerealis, B cinerea, G cingulat E turcicum and so on. Under the concentration 0.1g·mL^-1,it had strong inhibition to R. cerealis and B cinerea in vitro ,the inhibition rates were both 100%.The results in vivo also showed that the chloroform extract had strong pretective effect to Erysiphe graminis (DC.)Speer, the efficacy was 66.42% at the concentration of 5 mg/mL.4. Applying activity tracing ,at the same time R. cerealis and B cinerea were regarded as indicative germs, through column chromatography, Sephadex LH-20, crystal, preparation of HPLC and other means, nine compounds were isolated from the Mikania micrantha H.B.K Their number and the quality was recorded as follows:â… (740 mg),â…¡(25 mg),â…¢(10 mg),â…£(40 mg),â…¤(580 mg),â…¥(20 mg),â…¦(5 mg),â…§(7 mg),â…¨(500 mg).Their chemical structure were determined by means of chemical reactions and spectral means(IR,EI MS,¹H NMR,¹³C NMR,DEPT),and four of them were confirmed as stigmasterol,deoxymikanolide, dihydromikanolide andβ-Sitosterol.5. We studied on the essential oil extract technics of the whole of Mikania micrantha H.B.K.by hydrostillation (HD), supercritical CO₂ extraction (SCE) and distilled with petrol ether (PEE), and the extract rate was regarded as index. Results showed that the extract rate of this three methods was 0.67%,1.10% and 5.41%, and the supercritical CO2 extraction under the suitable condition had the highest extract rate . By GC-MS analysis of the essential oil with hydrostillation extracted,we found that it mainly contains Stigmasterol, 22,23-dihydro-(7.34%),Caryophyllene oxide(3.34%),Thujopsene(2.92%)and Cubenol(2.81%)and so on.6. We tested fungicidal activity of the essential oil extracted with hydrostillation by the inhibition rate against the mycelial growth and control effect against the Botrytis cinerea on tomato ,the results showed that it had definite inhibition to all the pathogens provided in the test., under the concentration 1.0 mg/mL,it had strong inhibition to F graminearum, R.cerealis and B cinerea , all inhibition rates were higher than 90%. In addition, the test of its control effect against the Botrytis cinerea on tomato showed that the essential oil had obviously protective effect and when concentration was 1.0 mg/L and 2.0 mg/L ,the rates were both higher than 60%.7. The fungicidal activities of the part of compounds were tested in vitro. Results showed that they had definite inhibiting effect of spore germination against two germs which were provided for the tested. When the concentration was 0.5 mg/mL,the constituentsâ… andâ…¤had strong inhibiting effect of spore germination against B cinerea,and the inhibition rates were both 92.34% and 85.48%,and at the same concentration the compoundsâ…¡,â…£,â…¤andâ…§also had good inhibition effect of spore germination against E. turcicum and the inhibition rates were 83.81%,76.38%,68.88% and 76.73%。...