| Rabdosia rubescens (Hemls.) Hara is widely distributed in Yangtze River and the Yellow River, Main origin in henan jiyuan Mount Taihang area. There are many ingredients with antitumor, resistance mutations and antioxidant activity. Although we had a more thorough biological active study in ingredients of Rabdosia rubescens and made great progress, but the current study concentrate on cancer treatment, and a very small part of the study is human pathogenic bacteria active research, however, the pesticide and activity of inhibiting fungal have not been still studied. This paper primarily studied on the bioactivity and chemical constituents from the Angle of pesticides. The main results are as follows:1. The chemical constituents of the aerial part of Rabdosia rubescens had been primarily studied by tube test. The results indicated that Rabdosia rubescens contains Volatile oils, Phenols, Tannins, Saccharides, Alkaloids, Flavonoids, Amino acids, Steroidal, Terpenoids. After purifying by repeatedly column chromatography in ordinary pressure and HPLC, three compounds (1, 2, 3) were obtained from ethyl acetate extract of the aerial part by bioactivity-guided fractionated. Compared with the standard spectra of chromatography chart such as MS,1H NMR and 13C NMR, the three compounds were separately identified as oridonin (1), rubescensine B (2) and 5-hydroxy-2-(4-hydroxy-3-methoxyphenyl)-6,7,8–tri- methoxy– flavone (3).2. The bioassay results showed that the compound 1 have no action of contact posining and stomach toxic to the 3rd instar larvae of Mythimna separata, and exhibited inhibitory to the mycelium growth of the tested 7 species of fungus, but the activity is weaker, which was less than 50% at the concentration of 500μg·mL-1. Three compounds had considerable inhibitory activity to the spore germination of the tested 4 species of fungus, but antifungal activity of three compounds (EC50, 668~3869μg·mL-1) was weaker than that of the contrast (EC50, 160~421μg·mL-1). The bioassay results also showed that compound 1 and 2 had stronger activity against three gram-positive bacteria, the values of minimal inhibitory concentration (MIC) were 15.63~31.25μg·mL-1. Compound 3 had no antibacterial activity against the tested bacteria.3. The water extraction phase of Rabdosia rubesce can induce disease resistance of wheat and cucumber. In a certain number and interval of induction, the ability of plants to resist disease will increase, along with the increase of concentration. The most obvious effect in water extraction phase is 100 times dilution, the highest relative defense effect on wheat powdery mildew and cucumber downy mildew were analyzed: 31.31% and 32.20%. It is better than salicylic acid at 100 mg·L-1, that can inducing resistance to 16.54%和16.91% (α=0.05). In addition, the results showed that the dilution can make the activity of wheat blade of peroxidase (POD), superoxide dismutase (SOD), polyphenol oxidase (PPO) phenylalanine ammonia enzyme (PAL) increased. The trend of four enzymes activity and the results of pot experiment are consistent, All of four enzymes, the change of PAL activity is the most obvious.
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