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81.
Jia An Xiang Wang Yajiang Jing Jianping Huang Qilong Wang Gang Zhang Jing Gao Liang Peng Wenli Huang Yonggang Yan 《Phyton》2023,92(5):1405-1420
Although Platycodon grandiflorum (Jacq.) A.DC. is a renowned medicine food homology plant, reports of excessive cadmium (Cd) levels are common, which affects its safety for clinical use and food consumption. To enable its Cd levels to be regulated or reduced, it is necessary to first elucidate the mechanism of Cd uptake and accumulation in the plant, in addition to its detoxification mechanisms. This present study used inductively couple plasma-mass-spectrometry to analyze the subcellular distribution and chemical forms of Cd in different tissues of P. grandiflorum. The experimental results showed that Cd was mainly accumulated in the roots [predominantly in the cell wall (50.96%–61.42%)], and it was found primarily in hypomobile and hypotoxic forms. The proportion of Cd in the soluble fraction increased after Cd exposure, and the proportion of insoluble phosphate Cd and oxalate Cd increased in roots and leaves, with a higher increase in oxalate Cd. Therefore, it is likely that root retention mechanisms, cell wall deposition, vacuole sequestration, and the formation of low mobility and low toxicity forms are tolerance strategies for Cd detoxification used by P. grandiflorum. The results of this study provide a theoretical grounding for the study of Cd accumulation and detoxification mechanisms in P. grandiflorum, and they can be used as a reference for developing Cd limits and standards for other medicine food homology plants. 相似文献
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83.
Brasilicardin A (BraA)是从致病性放线菌巴西诺卡菌(Nocardia brasiliensis) IFM 0406中发现的具有显著免疫抑制作用(IC50=0.057μg/mL)的二萜糖苷类化合物。BraA发挥免疫抑制活性的作用机制与现有临床常用的免疫抑制剂不同,BraA通过抑制氨基酸转运体L系统的转运进而影响T-淋巴细胞对氨基酸的摄入而发挥免疫抑制作用。相比目前已知的免疫抑制剂环孢菌素A、子囊霉素和他克莫司等,BraA在小鼠混合淋巴细胞反应中显示低毒、高效的优势。因此,BraA作为新型的免疫抑制剂,极具开发潜力,已成为全球免疫抑制剂发现新领域。但其结构复杂、合成困难,原菌种产率低且具有致病性,BraA及其类似物的获得已成为此类新型免疫抑制剂研究的瓶颈。本文综述了BraA的分子特征、药理活性、作用机制、目前获得的BraA类似物和衍生化方面的研究进展,以期为BraA及其类似物的高效生产提供参考。 相似文献
84.
我国山水林田湖草沙生命共同体及其保护和修复工程的理论研究和实践正逐渐开展,需要系统的学科理论支撑,景观生态学作为地理学和生态学的交叉科学,能够以其宏观空间理论和技术体系满足这一需求。本文将景观生态学作为山水林田湖草沙一体化保护和修复工程的支撑学科,首先,明确了山水林田湖草沙生命共同体是镶嵌的异质景观、具有景观的所有特征并遵循景观生态学原理;其次,阐述了景观生态建设理论如何应用于山水林田湖草沙一体化保护和修复工程的规划和评价;最后,总结景观生态建设研究的新趋势,提出待解决的理论和实践问题,并论述山水林田湖草沙一体化保护和修复工程如何为解决这些问题提供广阔的研究空间。景观生态学和山水林田湖草沙一体化保护和修复工程实践相结合,将为实现我国乃至全球生态、经济、社会可持续发展提供极为有效的途径。 相似文献
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86.
Antim K. Maurya Gaurav Aggarwal Sachin Vashisath Vikas Kumar Prof. Dr. Vijai K. Agnihotri 《化学与生物多样性》2023,20(8):e202300223
The aim of current work was to determine essential oils (EOs) composition from three Eucalyptus species, including E. citriodora, E. camaldulensis and E. globulus and assess their α-glucosidase inhibitory activity. The EOs were collected using the hydrodistillation technique and characterized by GC/MS, GC-FID and NMR. The isolated EOs from leaves parts of Eucalyptus species varied from 0.56 to 1.0 % on fresh weight basis. The content of the EOs was distinct according to the species. The most abundant metabolites were identified as citronellal (0–83.0 %), 1,8-cineole (0.2–44.8 %), spathulenol (0.4–16.1 %) α-pinene (0.4–15.9 %), p-cymene (3.7–11.9 %), citronellol (0–8.6 %), β-eudesmol (5.3–8.6 %) and β-pinene (0–7.1 %). The EOs obtained from targeted samples exhibited strong α-glucosidase inhibitory activity. These results are encouraging and underline that the EOs of Eucalyptus species may be a promising alternative source of natural antidiabetic. 相似文献
87.
Souad El Hafidi Khadija Bakhy Mohammed Ouhssine Abderrahim Benzakour Hamid Khamar Joseph Casanova Mathieu Paoli Félix Tomi 《化学与生物多样性》2023,20(1):e202201022
Cladanthus scariosus (Ball) Oberpr. & Vogt is endemic to Moroccan High Atlas. It is known under the vernacular names Irezghi or Irezgui. Three essential oil samples have been isolated from aerial parts and analyzed by combination of chromatographic and spectroscopic techniques [gas chromatography (GC) in combination with retention indices (RI), gas chromatography-mass spectrometry (GC/MS) and 13C-NMR spectroscopy]. The compositions of oil samples were dominated by monoterpenes: α-pinene sabinene, and terpinen-4-ol. Chamazulene and dihydrochamazulene isomers as well as various hemiterpene esters and analogs have been identified. To evidence a chemical variability, statistical analysis performed on 13 oil sample compositions allowed partitioning into three groups, mainly differentiated by their contents of sabinene, camphor, borneol, terpinen-4-ol, and germacrene D. 相似文献
88.
Eya Khemis Mayssa Ben Mustapha Ikbel Chaieb Roberta Ascrizzi Guido Flamini Abdel Halim Harrath Hichem Ben Jannet Afifa Zardi-Bergaoui 《化学与生物多样性》2023,20(2):e202200646
Due to the several side effects of synthetic pesticides, including environmental pollution, threats to human health, and the development of pest resistance to insecticides, the use of alternative healthy, available and efficient agents in pest management strategies is necessary. Recently, the use of essential oil obtained from aromatic plants has shown significant potential for insect pest management. For this reason, the essential oil isolated from seeds of Thapsia garganica L. was investigated for the first time for its chemical profile, and its toxicity and repellency effects against Tribolium castaneum adults. Qualitative and quantitative analyses of the chemical composition by gas chromatography coupled to mass spectrometry (GC/MS) revealed the presence of 18 organic volatiles representing 96.8 % of the total constituents. The main compounds were 1,4-dimethylazulene (51.3 %) followed by methyl palmitate (8.2 %), methyl linoleate (6.2 %) and costol (5.1 %). Concerning the repellent effect, results revealed that SEO (Seed Essential Oil) was very repellent towards T. castaneum adults, with 100 % repellency after 2 h of exposure. Furthermore, the essential oil exhibited remarkable contact toxicity against T. castaneum (93.3 % of mortality) at the concentration of 10 % (v/v). The median lethal dose (LD50) of the topical application of the seed essential oil was 4.4 %. These encouraging outcomes suggested that the essential oil from T. garganica seeds could be considered a potent natural alternative to residual persistent and toxic insecticides. 相似文献
89.
Alan V. Di Vittorio Kanishka B. Narayan Pralit Patel Katherine Calvin Chris R. Vernon 《Global Change Biology Bioenergy》2023,15(2):185-207
Projection of land use and land-cover change is highly uncertain yet drives critical estimates of carbon emissions, climate change, and food and bioenergy production. We use new, spatially explicit land availability data in conjunction with a model sensitivity analysis to estimate the effects of additional land protection on land use and land cover. The land availability data include protected land and agricultural suitability and is incorporated into the Moirai land data system for initializing the Global Change Analysis Model. Overall, decreasing land availability is relatively inefficient at preserving undeveloped land while having considerable regional land-use impacts. Current amounts of protected area have little effect on land and crop production estimates, but including the spatial distribution of unsuitable (i.e., unavailable) land dramatically shifts bioenergy production from high northern latitudes to the rest of the world, compared with uniform availability. This highlights the importance of spatial heterogeneity in understanding and managing land change. Approximately doubling the current protected area to emulate a 30% protected area target may avoid land conversion by 2050 of less than half the newly protected extent while reducing bioenergy feedstock land by 10.4% and cropland and grazed pasture by over 3%. Regional bioenergy land may be reduced (increased) by up to 46% (36%), cropland reduced by up to 61%, pasture reduced by up to 100%, and harvested forest reduced by up to 35%. Only a few regions show notable gains in some undeveloped land types of up to 36%. Half of the regions can reach the target using only unsuitable land, which would minimize impacts on agriculture but may not meet conservation goals. Rather than focusing on an area target, a more robust approach may be to carefully select newly protected land to meet well-defined conservation goals while minimizing impacts to agriculture. 相似文献
90.
摘要 目的:观察右美托咪定联合芬太尼对心脏瓣膜置换术患者细胞免疫功能的影响及在心脑保护中的作用。方法:纳入海南医学院第二附属医院2019年4月~2021年6月间接收的体外循环(CPB)下心脏瓣膜置换术患者97例,根据信封抽签法将患者分为对照组(芬太尼,48例)和观察组(右美托咪定联合芬太尼,49例)。对比两组血流动力学指标[平均动脉压(MAP)、心率(HR)]、心肌损伤指标[肌钙蛋白(cTnI)、肌酸激酶同工酶(CK-MB)、心型脂肪酸结合蛋白(HFABP)]、脑损伤指标[神经元特异性烯醇化酶(NSE)、S-100β]、细胞免疫功能、镇痛情况及不良反应发生率。结果:观察组CPB开始后10 min(T2)时间点HR、MAP低于对照组,CPB结束(T3)、术毕(T4)时间点HR、MAP高于对照组(P<0.05)。两组术前(T1)、术后24 h、术后48 h视觉模拟评分法(VAS)评分升高后降低(P<0.05),观察组术后24 h、术后48 h VAS评分低于对照组(P<0.05)。观察组术后48 h CD4+、CD4+/CD8+高于对照组,CD8+低于对照组(P<0.05)。观察组术后48 h cTnI、CK-MB、HFABP低于对照组(P<0.05)。观察组术后48 h NSE、S100B低于对照组(P<0.05)。观察组的不良反应发生率低于对照组(P<0.05)。结论:心脏瓣膜置换术患者选用右美托咪定联合芬太尼麻醉方案,有助于减轻疼痛,稳定血流动力学,减轻免疫抑制,同时还可发挥心脑保护效果,降低不良反应发生率,是一种可靠的麻醉方案。 相似文献