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Competing Interests: Conflicts of interest: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

This paper described the extraction procedure of six extracts from Abutilon theophrasti Medic. leaves and evaluated antioxidant and antibacterial activity of different extracts by hydroxyl radical, DPPH radical scavenging, broth micro-dilution and agar-well diffusion methods. The six extracts were prepared by the two extraction procedures: (I) water was the extraction solvent; (II) 90% alcohol extract was extracted by petroleum ether, chloroform, ethyl acetate and n-butanol in turn. Extract yields were 7.34%, 7.31%, 0.45%, 0.12%, 2.70% and 5.68% for extract I to VI. It was revealed that the various extracts had effective antibacterial activity against four test strains from Staphylococcus aureus (ATCC 25923), Streptococcus (ATCC 49619), Escherichia coli (ATCC 25922) and Salmonella (ATCC 01303); meanwhile, the six extracts demonstrated potent antioxidant activity, achieved by hydroxyl radical and DPPH radical scavenging assay. Minimum inhibitory concentrations (MICs) for the bacterial species ranged from 2.21 to 539.46 mg/ml, diameter of inhibition zone ranged from 2.08 to 15.05mm. The scavenging •OH and DPPH• rates were 62.37% to 81.86% with the concentration 0.06 to 1.89mg/ml and 37.80% to 81.23% with the concentration 1.07 to 35.52mg/ml. According to the results, these extracts have antioxidant and antibacterial activity. In view of all the facts collectively, the six extracts will become natural and nontoxic antioxidant and antibacterial agent, and be applied in food and pharmaceutical industries for the prevention or treatment caused by microorganisms and free radicals.

Objective: To optimize the preparation process of solid dispersions of ginkgolides to improve the drug dissolution., Method: The influence of formulation and preparation technology on drug release from solid dispersions was investigated by single factor test. The X-ray diffraction analysis (XRD) and differential scanning calorimetry (DSC) were used to characterize the solid dispersions of ginkgolides., Result: The solubilization efficiency of solid dispersions using PVP k30 as carrier was better than that taking poloxamer 188 or HPMC as matrix. The results of XRD and DSC showed that ginkgolides existed in solid dispersion at amorphous form or solvates form. The dissolution rate of ginkgolide B in solid dispersion was increased dramatically compared with raw material., Conclusion: Solid dispersions could significantly improve solubility and dissolution rate of ginkgolides.

With biological simulation experiment and chemical analysis, this paper studied the allelopathy of carbohydrates, amino acids and organic acids in the root exudates from two genotypes soybeans (9536 and Jilin 30) on the pathogenic fungi of root rot. The results showed that the water soluble carbohydrates in the root exudates from test soybeans significantly promoted the growth of Fusarium oxysporium and Fusarium semitectum at low concentrations and inhibited their growth at high concentrations, but had no evident influence on Gliocladium roseum. The water soluble amino acids from the root exudates demonstrated different actions, i. e., at middle and high concentrations, those from 9536 significantly inhibited the growth of Fusarium oxysporium, Fusarium semitectum and Gliocladium roseum, while those from Jilin 30 mostly promoted their growth. The organic acids from the root exudates of 9536 and Jilin 30 significantly inhibited the growth of Fusarium oxysporium, Fusarium semitectum and Gliocladium roseum. It's suggested that there existed interactions between the root exudates of the two genotypes soybeans and the pathogenic fungi of root rot. Different genotypes of soybean may have different allelopathy on pathogenic fungi of root rot.

Different solvents including cyclohexane, ethyl acetate, n-butanol and XAD-4 resin were used to extract the allelochemicals from the decomposing products of soybean stubs. The results showed that the germination of soybean seeds were inhibited at initial stages by the solution extracted with cyclohexane, ethyl acetate, n-butanol and resin from the decomposing products of soybean stubs that had been incubated for 2 and 4 weeks. The inhibition was gradually weakened with the time. When concentrations of the ethyl acetate and resin fractions were 0.50, 1.00 gDW.ml-1 and when their concentrations were 0.10, 0.25 gDW.ml-1, their RI (the index of allelopathic effect) value of soybean radicle length reached significant level. The RI values of the former and those of the cyclohexane fractions reached significant level also. The chemical constituents of allelopathic fractions were identified by GC-MS as organic acids, phenol, aldehyde, ketone, benzene, amine, nitrile, ester and some other compounds, some of which were allelochemicals.

Allelopathic effect of root exudates on pathogenic fungi of root rot in continuous cropping soybean was studied by sand culture, water culture, and indoor culture experiments. The results showed that allelopathic promotion of root exudates on the growth of Fusarium semitectum, Gliocladium roseum and Fusarium oxysporum, especially Fusarium semitectum reached significant level or especially significant level in continuous cropping soybean compared with the control. Allelopathic promotion of root exudates on the growth of Fusarium semitectum and Gliocladium roseum in continuous cropping soybean was distinctly larger than that in rotation soybean, and the difference reached significant level under their low concentration. Allelopathic promotion of high concentration of root exudates on the growth of Fusarium semitectum was smaller than that of low concentration of root exudates, and the difference reached significant level in continuous cropping soybean. Allelopathic inhibition of high concentration of phthalic acid and propanedioic acid (L5 and B5) on the growth of Fusarium semitectum. Gliocladium roseum and Fusarium oxysporum, especially Fusarium semitectum reached significant level or especially significant level compared with the control. However, allelopathic promotion of low concentration of phthalic acid and propanedioic acid on the growth of Fusarium semitectum, Gliocladium roseum and Fusarium oxysporum partly reached significant level.