Papers by Keyword: Aqueous Extracts

Abstract: An incubation experiment was carried out to investigate the inhibitory effects of aqueous extracts of 32 common tropical green plant species from 24 families on nitrification. The results indicated that the nitrification inhibitory effects of Calliandra haematocephala belonging to Mimosaceae, Dracaena cambodiana belonging to Liliaceae, Duranta repens belonging to Verbenaceae, Alstonia scholaris belonging to Apocynacea, Terminalia mantaly belonging to Combretaceae and Polyalthia longifolia belonging to Annonaceae were better than DCD, which had more obvious potential applications than other plants inhibited nitrification. The inhibitory effects of active substances in plants were affected by extract temperature causing by solubility and thermal stability of active substances. Duranta repens had the most potential for development in this study as a fertilizer additive. The inhibitory effects of aqueous extracts of Duranta repens leaves on nitrification increased with increasing concentration of aqueous extracts, the strongest inhibitory effect on nitrification occurred after 14 d of incubation.

Abstract: Tropical plants contain a variety of secondary metabolites, and plant aqueous extracts can be used as urease inhibitors to improve nitrogen use efficiency and reduce the negative environmental effects. An incubation experiment was carried out to investigate the effects of aqueous extracts of 32 common tropical green plant species from 24 families on urea hydrolysis. The results indicated that the aqueous extracts from 3 of the common tropical green plants (Pterocarpus indicus, Callistemon rigidus, Terminalia mantaly) belonging to Leguminosae, Myrtaceae and Combretaceae respectively showed better inhibitory effects on urease than hydroquinone as a chemical inhibitor, and had more obvious potential applications. The inhibitory effects of active substances in plants were affected by extract temperature causing by solubility and thermal stability of active substances. T. mantaly had the most potential for development in this study as a fertilizer additive. The inhibitory effects of aqueous extracts of T. mantaly leaves on urea hydrolysis increased with increasing concentration of aqueous extracts, the strongest inhibitory effect on urease occurred after 2-3 d of incubation.

Abstract: Tropical forest plants contain a variety of secondary metabolites, and plant aqueous extracts can be used as urease and nitrification inhibitors to improve nitrogen use efficiency and reduce the negative environmental effects. An incubation experiment was carried out to investigate the effects of aqueous extracts of 60 tropical forest plant species from 16 families on urea hydrolysis and nitrification. The results indicated that the aqueous extracts from 3 of the tropical forest plants (Aphanamixis polystachya, Toona sinensis, Vatica mangachapoi) belonging to meliaceae and dipterocarpaceae showed good inhibitory effects on urease, and the aqueous extracts from 5 of the tropical forest plants (Cryptocarya chinensis, Cryptocarya hainanensis, Toona sinensis, Khaya senegalensis, Hopea hainanensis) belonging to lauraceae, meliaceae and ipterocarpaceae showed good inhibitory effects on nitrification. The inhibitory effects of active substances in plants were affected by extract temperature, and the plants can be divided into three types by solubility and thermal stability. Toona sinensis had the most potential for development in this study as urea additive. The inhibitory effects of aqueous extracts of Toona sinensis leaves on urea hydrolysis and nitrification increased with increasing concentration of aqueous extracts, the strongest inhibitory effect on urease occurred after 2-3 d of incubation, and the strongest inhibitory effect on nitrification occurred after 2-3 weeks of incubation.

Abstract: Autotoxicity of aqueous extracts from roots, stems and leaves of flowering Chinese cabbage (Brassica campestris L. ssp. chinensis var. utilis Tsen et Lee) were studied by hydroponic in different concentrations (0.5g/L, 2g/L, 5g/L). The results showed that in solution with aqueous extracts from roots, stems and leaves, the growth of flowering Chinese cabbage were inhibited, leaf chlorophyll content declined, photosynthesis rate were affected, activities of SOD, POD and CAT were changed, MDA concentration increased, thus cell membrane permeability of flowering Chinese cabbage was damaged. The autotoxicity of aqueous extracts in flowering Chinese cabbage increased with the extracts concentration increasing.

Abstract: The caterpillar-shaped Chinese medicinal mushroom cordyceps sinensis has been used in China as a food or herbal medicine to treat numerous diseases. As uncultivated cordyceps sinensis is becoming extremely rare, the price of this herbal medicine is very high. In order to study the pharmacological effects and to minimize the cost, an economical method for culturing of cordyceps sinensis has been developed, which could be processed to large-scale production. We compared the pharmacological components, and the apoptosis inducing activity in BmN cells with both cultured and uncultivated cordyceps sinensis. Based on the real-time PCR of five genes in cyclin family, the aqueous extracts at a concentration of 1mg/ml inhibited 90% of the gene expression when the cells were for 48 hours. Our results indicate that cultured cordyceps sinensis has a higher content of polysaccharide and the aqueous extract shows significant inhibition effect on the BmN cells.

Abstract: In laboratory bioassay, conducted to study the allelopathic influence of aqueous extracts (0, 2.5, 5.0, 7.5, 10.0% concentration) of twelve hedgerow plant species (Amorpha fruticosa L., Citrus reticulate Banco., Coronilla varia L., Eriobotrya japonica Thunb., Eulaliopsis binata Retz., Gynura bicolor DC., Hemerocallis citrine Baroni., Medicago sativa L., Morus alba L., Toona sinensis Roem., Vetiveria zizanioides L., Zanthoxylum schinifolium Sieb.) which planted in the purple hilly area of Sichuan basin in China was on the germination and seedling growth of wheat (Triticum astivum L.). At 10.0% concentration, The aqueous extracts of twelve hedgerow plant species significantly inhibited the seed germination and seedling growth of wheat except that A. fruticosa, E. binata and V. zizanioides extracts had no effect or slight inhibition on germination of wheat, but the degree of inhibition was species dependent. The allelopathic effect of aqueous extracts from hedgerow plants on wheat was maximum with G. bicolor, H. citrine, C. varia and M. sativa in terms of germination, and G. bicolor , M. sativa, M. alba and H. citrine in terms of shoot length, root length and dry weight, respecitively. The degree of inhibition increased with increase in concentration. Duplication of this work under field conditions is needed, for which the results of this study will form a valuable base.