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881.
882.
The co-storage of two or more Chinese herbal medicines can effectively prevent the herbs from the damage by pests. Thus, it is important to protect herbs and crops to study Chinese herbal medicines and their medicinal components against storage pests. This study aimed to assess the insecticidal activities and repellent effect of essential oils (EOs) extracted from fruits at different periods from Zanthoxylum myriacanthum Wall. ex Hook. f. (1 h, 2 h, 3–5 h and 5–7 h), and their major compounds against three kinds of pests (Tribolium castaneum, Lasioderma serricorne, and Liposcelis bostrychophila). The results of gas chromatography-mass spectrometer analysis revealed homomyrtenol (22.56 %, 28.01 %, 28.48 % and 28.41 %, respectively) and p-cymene (30.58 %, 13.95 %, 24.97 % and 6.85 %, respectively) were the common major compounds of the EOs at 1 h, 2 h, 3–5 h, and 5–7 h. m-Cymene contents in EOs of fruits, 1 h, 2 h and 3–5 h were 3.85 %, 0.95 %, 6.71 %, and 6.15 %, respectively. According to Principal component analysis (PCA), the composition of fruits′ EO was significantly different from other EOs due to the different collection times. The bio-assays showed that EOs and major compounds were toxic to all three pests, but the fumigation effect on L. bostrychophila was not noticeable. EOs extracted at different times had a repellent effect on the three pests at the highest concentration (78.63 nL/cm2), but the attractive effects of the EOs of 3–5 h, 5–7 h, and p-cymene were observed at the low concentrations (3.15, 0.63 and 0.13 nL/cm2). Our results suggest that Z. myriacanthum have the potential to be developed as biological insecticides.  相似文献   
883.
小兴安岭兴安落叶松、泥炭藓沼泽是我国典型贫营养型沼泽。沼泽中树木生长发育不良,泥炭藓和常绿小灌木发育十分良好。这与沼泽水文状况和泥炭中营养元素和微量元素有关。各种植物的主要微量元素硼、铜、钴、锰、锌等含量不同,植物的不同器官中的含量亦不同,而且随季节而变化。狭叶杜香和甸杜的主要微量元素含量特点及其季节变化规律基本相似,两种泥炭藓相似,都与兴安落叶松有明显的区别。 本文重点探讨植物体内主要微量元素及其含量变化规律,为揭示贫营养型森林沼泽生态、为合理利用与改造沼泽提供依据。  相似文献   
884.
Five new ent-pimarane diterpenes ( 1 – 5 ) and five known analogs ( 6 – 10 ) were isolated from the aerial parts of Siegesbeckia pubescens. Their structures, including absolute configurations, were determined by comprehensive spectroscopic methods especially 1D and 2D NMR and quantum chemical electronic circular dichroism calculations. All the isolated compounds were evaluated for their cytotoxicity against human BT549, A549 and H157 cancer cell lines. Among them, compounds 1 and 2 showed mild cytotoxicity against lung cancer cell lines H157 with IC50 values of 16.35±2.59 and 18.86±4.83 μM, respectively.  相似文献   
885.
The heartwood of Syringa oblata Lindl. (SO) is one of Mongolian folk medicines to treat insomnia and pain, while its pharmacological evaluation and underlying mechanism remain unclear. In this study, the sedative effect of ethanol extract of SO (ESO) was evaluated with the locomotor activity test and the threshold dose of pentobarbital sodium-induced sleep test in mice, and the hot plate test, acetic acid-induced writhing test, and formalin test in mice were used to evaluate its analgesic effect. The underlying mechanism of ESO analgesia was explored by RT-PCR and western blot analysis, which is associated with the regulation of the NF-κB signaling pathway. Besides, the main constituents of ESO were characterized by LC/MS data analysis and comparison with isolated pure compounds. The current findings brought evidence for clinical application and further pharmacological and phytochemical studies on SO.  相似文献   
886.
诱发小麦成熟胚愈伤组织及其再生植株抗盐性变异的研究   总被引:23,自引:3,他引:20  
沈银柱  孟庆昌 《遗传学报》1993,20(3):253-261
本研究以普通小麦成熟胚为起始材料,以平阳霉素(PYM)和正定霉素(ZDM)为诱变剂。发现不同基因型对药物的敏感性不同,其中对药物敏感的在含盐筛选培养基上的存活率高。在诱导培养基内添加一定量的诱变剂可以产生耐盐变异。这种抗性愈伤组织转入与筛选培养基含盐量相同的分化培养基,比较容易产生耐盐再生植株。其M_1、M_2代较亲本系表现株高降低,穗长变短、籽粒饱满度也差;M_1代的结实率仅有5.5%,M_2代恢复到40.9%。利用M_1代和亲本系实生苗叶片,进行脯氨酸含量测定。发现耐盐变异株在无盐的Hoagland溶液中,游离脯氨酸的含量超过亲本系,对盐胁迫不敏感,其耐受力强于对照,具有一定的抗盐稳定性。  相似文献   
887.
This study aims to explore the protective effects of Picroside III, an active ingredient of Picrorhiza scrophulariiflora, on the intestinal epithelial barrier in tumor necrosis factor-α (TNF-α) induced Caco-2 cells and dextran sulfate sodium (DSS) induced colitis in mice. Results show that Picroside III significantly alleviated clinical signs of colitis including body weight loss, disease activity index increase, colon shortening, and colon tissue damage. It also increased claudin-3, ZO-1 and occludin expressions and decreased claudin-2 expression in the colon tissues of mice with colitis. In vitro, Picroside III also significantly promoted wound healing, decreased the permeability of cell monolayer, upregulated the expressions of claudin-3, ZO-1 and occludin and downregulated the expression of claudin-2 in TNF-α treated Caco-2 cells. Mechanism studies show that Picroside III significantly promoted AMP-activated protein kinase (AMPK) phosphorylation in vitro and in vivo, and blockade with AMPK could significantly attenuate the upregulation of Picroside III in ZO-1 and occludin expressions and the downregulation of claudin-2 expression in TNF-α treated Caco-2 cells. In conclusion, this study demonstrates that Picroside III attenuated DSS-induced colitis by promoting colonic mucosal wound healing and epithelial barrier function recovery via the activation of AMPK.  相似文献   
888.
To determine 15 bile acid metabolic products in human serum by liquid chromatography-tandem mass spectrometry (LC/MS/MS) and value their diagnostic outcome in primary biliary cholangitis (PBC). Serum from 20 healthy controls and 26 patients with PBC were collected and went LC/MS/MS analysis of 15 bile acid metabolic products. The test results were analyzed by bile acid metabolomics, and the potential biomarkers were screened and their diagnostic performance was judged by statistical methods such as principal component and partial least squares discriminant analysis and area under curve (AUC). 8 differential metabolites can be screened out: Deoxycholic acid (DCA), Glycine deoxycholic acid (GDCA), Lithocholic acid (LCA), Glycine ursodeoxycholic acid (GUDCA), Taurolithocholic acid (TLCA), Tauroursodeoxycholic acid (TUDCA), Taurodeoxycholic acid (TDCA), Glycine chenodeoxycholic acid (GCDCA). The performance of the biomarkers was evaluated by the AUC, specificity and sensitivity. In conclusion, DCA, GDCA, LCA, GUDCA, TLCA, TUDCA, TDCA and GCDCA were identified as eight potential biomarkers to distinguish between healthy people and PBC patients by multivariate statistical analysis, which provided reliable experimental basis for clinical practice.  相似文献   
889.
890.
Zea mays (Z. mays) is one of the main cereal crops in the world, and it′s by-products have exhibited medicinal properties to explore. This article intends to review the chemical compositions and pharmacological activities of by-products of Z. mays (corn silks, roots, bract, stems, bran, and leaves) which support the therapeutic potential in the treatment of different diseases, with emphasis on the natural occurring compounds and detailed pharmacological developments. Based on this review, 231 natural compounds are presented. Among them, flavonoids, terpenes, phenylpropanoids, and alkaloids are the most frequently reported. The by-products of Z. mays possess diuretic effects, hepatoprotective, anti-diabetic, antioxidant, neuroprotective, anti-inflammatory, anti-cancer, plant protection activity, and other activities. This article reviewed the phytochemistry and pharmacological activities of Z. mays for comprehensive quality control and the safety and effectiveness to enhance future application.  相似文献   
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