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排序方式: 共有4903条查询结果,搜索用时 20 毫秒
1.
目的研究羌活Notopterygium incisum的香豆素类成分及其抗炎活性。方法采用硅胶、HPLC等柱色谱方法进行分离纯化,通过质谱、核磁共振波谱数据鉴定化合物的结构;采用脂多糖(LPS)诱导的小鼠巨噬细胞RAW 264.7炎症反应模型,考察羌活中香豆素类成分对炎症反应模型一氧化氮(NO)生成的影响。结果从羌活甲醇提取物分离得到24个香豆素类化合物,分别鉴定为异欧前胡素(1)、川白芷素(2)、补骨脂素(3)、香柑内酯(4)、茵陈素(5)、欧芹酚(6)、5-去氢羌活醇(7)、环氧脱水羌活醇(8)、7″-O-甲基异羌活醇(9)、佛手柑素(10)、7-异戊烯氧基-6-甲氧基-香豆素(11)、栓翅芹烯醇(12)、羌活醇(13)、去甲呋喃羽叶芸香素(14)、异羌活醇(15)、蛇床夫内酯(16)、6-异戊烯氧基伞形花内酯(17)、紫花前胡苷元(18)、异虎耳草素(19)、紫花前胡苷(20)、前胡苷V(21)、前胡苷I(22)、印枳苷元-11-O-β-D-吡喃葡萄糖基-(1→6)-β-D-吡喃葡萄糖苷(23)、羌活苷(24)。化合物7~10、13和15抑制LPS诱导的RAW 264.7细胞NO生成活性最强,最大半数抑制浓度(IC_(50))值为8.50~35.12μmol/L。结论化合物7为新的天然产物,化合物17为首次从羌活中分离得到;C-5位上具有多烯烃结构的香豆素抑制LPS诱导的RAW 264.7细胞NO生成活性较强。 相似文献
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Hale Z Toklu Judy Muller-Delp Zhihui Yang ?ehkar Oktay Yasemin Sakarya Kevin Strang Payal Ghosh Michael D Delp Philip J Scarpace Kevin KW Wang Nihal Tümer 《Journal of cerebral blood flow and metabolism》2015,35(12):1950-1956
Overpressure blast-wave induced brain injury (OBI) leads to progressive pathophysiologic changes resulting in a reduction in brain blood flow, blood brain barrier breakdown, edema, and cerebral ischemia. The aim of this study was to evaluate cerebral vascular function after single and repeated OBI. Male Sprague-Dawley rats were divided into three groups: Control (Naive), single OBI (30 psi peak pressure, 1 to 2 msec duration), and repeated (days 1, 4, and 7) OBI (r-OBI). Rats were killed 24 hours after injury and the basilar artery was isolated, cannulated, and pressurized (90 cm H2O). Vascular responses to potassium chloride (KCl) (30 to 100 mmol/L), endothelin-1 (10−12 to 10−7 mol/L), acetylcholine (ACh) (10−10 to 10−4 mol/L) and diethylamine-NONO-ate (DEA-NONO-ate) (10−10 to 10−4 mol/L) were evaluated. The OBI resulted in an increase in the contractile responses to endothelin and a decrease in the relaxant responses to ACh in both single and r-OBI groups. However, impaired DEA-NONO-ate-induced vasodilation and increased wall thickness to lumen ratio were observed only in the r-OBI group. The endothelin-1 type A (ETA) receptor and endothelial nitric oxide synthase (eNOS) immunoreactivity were significantly enhanced by OBI. These findings indicate that both single and r-OBI impairs cerebral vascular endothelium-dependent dilation, potentially a consequence of endothelial dysfunction and/or vascular remodelling in basilar arteries after OBI. 相似文献
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《Transfusion Clinique et Biologique》2020,27(4):229-236
BackgroundRed blood cell (RBC), which is the most commonly transfused blood component, due to its ability to save a life in absence of any other blood components, can be stored up to maximum 6 weeks by following standard preservation procedure. During storage, RBC undergoes various biophysical and biochemical changes (commonly known as storage lesion) for which blood transfusion with “old RBC” shows a lot of clinical problems especially relevant to critically ill patients. Recent research on S-nitrosylation of haemoglobin to improve oxygen delivery of banked blood revealed the important role of nitric oxide (NO) in protecting storage lesion.Materials and methodsIn the present study, we used various “NO donating” chemicals with different NO release dynamics and chemistries in RBC storage cocktails to test the effects of NO on storage lesion. Changes in different storage markers were evaluated after 7 days storage of pre-treated RBC.ResultsAll the NO donors have shown protection against hemolysis. However, S-nitroso glutathione (GSNO) ranks first in shielding RBCs from storage lesion and additionally, it helps in elevating the value of 2, 3-di phosphoglycerate (2, 3-DPG), improving the RBC membrane fluidity and decreasing the adhesion towards endothelial monolayer.DiscussionPresent study reveals that NO released from NO donors confers protection against storage lesions of the RBC. Further, the study confirms that pre-treatment with GSNO, a NO donor and a nitrosylating agent, ensures the best protection to RBC during low temperature storage, when compared to other NO donor treatments. 相似文献
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目的 对泽泻中原三萜、降三萜和倍半萜化学成分分离和鉴定及其抗炎活性进行研究;方法 采用硅胶柱色谱、凝胶柱色谱、高速逆流色谱、中压制备色谱和半制备色谱法对泽泻中各类化合物进行分离,利用1H和13C NMR对分离化合物进行结构鉴定;通过测定各单体对LPS(1 μg·mL-1)诱导Caco-2细胞中NO生成的抑制作用评价其抗炎活性。结果 从泽泻中分离得到19个化合物,包括8个原三萜类成分:alisol A 23 acetate (1),alisol G (2),16-oxo-11-anhydroalisol A (3),16-oxo-11-anhydroalisol A 24 acetate (4),alisoma A (5),alisoma B (6),alismanol J (7),alismanol B (8);1个降三萜类成分:17-nor-protostane (9);9个倍半萜类成分:orientalol L (10),orientalol M (11),orientalol N (12),orientalol O (13),orientalol P (14),alismanoid A (15),heyneanones D (16),leptocladol B (17),chabrolidione B (18);1个木脂素类成分:pnoresinol (19)。原三萜类成分均具有显著的抑制活性,化合物1-8 的IC50分别为2.1、0.9、7.3、10.0、11.0、16.0、13.5和10.5 μmol·mL-1,降三萜及倍半萜活性较弱,化合物10、11、13、15、16和17的IC50分别为24.0、26.2、30.6、15.7、17.2和15.2 μmol·mL-1。结论 化合物16、17、18和19为该植物首次分离得到。首次报道了倍半萜类成分对LPS诱导Caco-2细胞中NO生成的抑制作用,其中alisol A 23 acetate和alisol G的抑制活性最强。 相似文献
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M.C.P.M. da Cunha M. Weber F.C. Nart 《Journal of electroanalytical chemistry (Lausanne, Switzerland)》1996,414(2):163-170
The adsorption of nitrate ions on gold and platinum electrodes in acid solution has been studied in acidic solution using in situ FURS. It is found that nitrate is adsorbed probably with a two-fold coordination on gold electrodes as suggested by the adsórbate potential-dependent spectral feature centered between 1440 and 1460 cm?1. In addition, partial reduction of the nitrate ions at more negative potentials (ca. 0.05 V) generates nitrite ions in solution. These ions are co-adsorbed with nitrate ions in the double layer region of potentials. The nitrite ions seem to be adsorbed O-down with a one-fold or two-fold coordination. Platinum electrodes are found to be much more active catalytically to nitrate reduction than gold electrodes. The reduction of nitrate ions at potentials below 0.8 V generates an adsorbed product presenting a potential-dependent band at 1540 to 1580 cm?1 which has been identified as adsorbed NO. 相似文献
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槟榔碱对血管内皮细胞增殖和分泌NO的影响 总被引:1,自引:2,他引:1
目的:观察去除槟榔碱干预后血管内皮细胞(EC)增殖和分泌一氧化氮(NO)的变化。方法:采用MTT法检测去除槟榔碱干预后的EC存活率,硝酸还原酶法检测EC分泌NO量。结果:30μg/ml~90μg/ml槟榔碱干预EC 24h,去除刺激并继续孵育48h,EC的增殖能力可恢复,且分泌NO增多(p〈0.05);但120μg/ml槟榔碱干预24h、30μg/ml~120μg/ml槟榔碱干预48h并继续孵育48h,EC的增殖能力难以恢复(P〈0.05)。结论:去除低浓度、短时间槟榔碱干预后EC增殖能力的恢复可能与具有自我保护效应的NO分泌量增加有关。 相似文献
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目的:探讨生脉注射液对心肌缺血Beagle犬血压、心率、心电图及血清C-反应蛋白、NO水平的影响。方法:30只Beagle犬随机分为5组,即空白对照组、模型对照组、生脉注射液小剂量组(0.80 mL·kg -1 )、生脉注射液大剂量组(3.20 mL·kg -1 )和单硝酸异山梨酯组(0.07 mL·kg -1 )。采用皮下注射盐酸异丙肾上腺素制备心肌缺血模型,同时给予药物治疗。记录给药后1、6、12、24 h,犬血压、心率和心电图变化,并检测血清C-反应蛋白和NO含量。结果:与空白对照组比较,模型组Beagle犬平均动脉压(MBP)明显降低(P<0.01),心率(HR)明显加快(P<0.01或P<0.05),心电图ΔST值明显增大(P<0.01),生脉注射液能改善上述症状,但作用趋缓。生脉注射液对血清C-反应蛋白含量降低和NO含量升高有明显的对抗作用,与模型组比较,差异有统计学意义(P<0.01或P<0.05)。结论:生脉注射液能改善心肌缺血Beagle犬生理指标,其机制可能与调节C-反应蛋白代谢,抑制NO分泌有关。 相似文献