Recent advances on the biodiversity, ecological roles, and functional metabolites of endophytes were summarized with some speculative comments for better understanding of this subject.
The oligosaccharide elicitor from the mycelial wall of an endophytic Colletotrichum sp. B501 promoted the production of artemisinin in Artemisia annua L. hairy root culture. When hairy roots of 22-day-old cultures (la...The oligosaccharide elicitor from the mycelial wall of an endophytic Colletotrichum sp. B501 promoted the production of artemisinin in Artemisia annua L. hairy root culture. When hairy roots of 22-day-old cultures (later growth phase) were exposed to the elicitor (20 mg/L) for 4 d, the maximum content of artemisinin reached 1.15 mg/g, a 64.29% increment over the control. The electron X-ray microanalysis disclosed the rapid accumulation of Ca 2+ in the elicited cortical cells of hairy root. The electronic microscope observation revealed the high electron density area in vacuole of elicited cells. During the first day of elicitation the peroxidase activity of hairy roots was improved sharply. Some cellular morphological changes including cell shrinkage, condensation of cytoplasm and nuclear fragmentation, coincident with the appearance of DNA ladders, were observed after the third day of elicitation. It was suggested that the oligosaccharide elicitor triggered the programmed cell death, which may provide the substance or chemical signal for artemisinin biosynthesis.展开更多
In addition to six known flavonoids quercitrin, hyperoside, avicularin, rutin, quercetin and kaemferol, a new flavonol glycoside named 6″_O_acetyl quercetin 3_O_β_ D _alloside (1) was isolated from the aerial par...In addition to six known flavonoids quercitrin, hyperoside, avicularin, rutin, quercetin and kaemferol, a new flavonol glycoside named 6″_O_acetyl quercetin 3_O_β_ D _alloside (1) was isolated from the aerial parts of Hypericum perforatum L. The structures were determined on the basis of spectroscopic methods (UV, IR, FAB_MS, 1H_NMR and 13 C NMR). Antifungal assay of all compounds showed that metabolite 1, quercitrin and quercetin were inhibitory to the growth of phytopathogenic fungus Helminthosporium sativum Pamel King et Bakke with minimum inhibitory concentrations (MICs) of 25, 50 and 50 μg/mL, respectively. Moreover, glycoside 1 and quercitrin were also shown to be able to inhibit the growth of Fusarium graminearum Schw. with MIC of 100 μg/mL. The MICs of ketoconazole used as control against the test fungi were 0.5 μg/mL in our assay.展开更多
文摘Recent advances on the biodiversity, ecological roles, and functional metabolites of endophytes were summarized with some speculative comments for better understanding of this subject.
文摘目的:研究芦荟多糖的提取、纯化工艺及体外抗肿瘤活性,为芦荟的产业化开发提供实验依据。方法:采用水提醇沉,三氯乙酸法除蛋白,DEAE-52离子交换色谱分离。用Sephacryl S-400凝胶柱层析纯化并确定芦荟多糖的相对分子量,HPLC法检测纯度,GC法鉴别单糖组成及分子摩尔比。以MTT法观察其体外抗肿瘤活性等。结果:从中华芦荟(Aloe vera L.var. chinesis(Haw.)Berger.)凝胶冻干粉中提取分离得到纯多糖AVP,经HPLC检测为单一对称峰,相对分子量为86000,由甘露糖和葡萄糖组成,摩尔比为10.3∶1.0。AVP对人肝癌细胞(SMMC-7721)、人胃癌细胞(BGC-823)及人肺癌细胞(A549)的增殖均有抑制作用。结论:该法分离的芦荟多糖AVP纯度好,收率高达3.6%,可用于进一步的研究和开发,提高芦荟的资源利用率。
文摘The oligosaccharide elicitor from the mycelial wall of an endophytic Colletotrichum sp. B501 promoted the production of artemisinin in Artemisia annua L. hairy root culture. When hairy roots of 22-day-old cultures (later growth phase) were exposed to the elicitor (20 mg/L) for 4 d, the maximum content of artemisinin reached 1.15 mg/g, a 64.29% increment over the control. The electron X-ray microanalysis disclosed the rapid accumulation of Ca 2+ in the elicited cortical cells of hairy root. The electronic microscope observation revealed the high electron density area in vacuole of elicited cells. During the first day of elicitation the peroxidase activity of hairy roots was improved sharply. Some cellular morphological changes including cell shrinkage, condensation of cytoplasm and nuclear fragmentation, coincident with the appearance of DNA ladders, were observed after the third day of elicitation. It was suggested that the oligosaccharide elicitor triggered the programmed cell death, which may provide the substance or chemical signal for artemisinin biosynthesis.
文摘In addition to six known flavonoids quercitrin, hyperoside, avicularin, rutin, quercetin and kaemferol, a new flavonol glycoside named 6″_O_acetyl quercetin 3_O_β_ D _alloside (1) was isolated from the aerial parts of Hypericum perforatum L. The structures were determined on the basis of spectroscopic methods (UV, IR, FAB_MS, 1H_NMR and 13 C NMR). Antifungal assay of all compounds showed that metabolite 1, quercitrin and quercetin were inhibitory to the growth of phytopathogenic fungus Helminthosporium sativum Pamel King et Bakke with minimum inhibitory concentrations (MICs) of 25, 50 and 50 μg/mL, respectively. Moreover, glycoside 1 and quercitrin were also shown to be able to inhibit the growth of Fusarium graminearum Schw. with MIC of 100 μg/mL. The MICs of ketoconazole used as control against the test fungi were 0.5 μg/mL in our assay.
