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《高校化学工程学报》2021,35(5)
为了有效利用油茶资源,提高茶皂苷元的抗氧化活性,对其进行结构修饰制备了茶皂苷元缩氨基硫脲及其锌配合物,使用紫外光谱(UV)、红外光谱(IR)、元素分析和核磁共振氢谱表征其结构,对合成工艺进行了优化,以DPPH·、ABTS~+·、·OH清除率为指标评价其抗氧化活性,并与抗氧化调节因子Keap1进行了分子对接,探讨其作用机制。结果表明,优化后的反应条件为:茶皂苷元与硫代氨基脲的量比为1:1.2,冰乙酸为催化剂,温度75℃,反应时间8 h,茶皂苷元缩氨基硫脲产率79.6%,纯度92%;茶皂苷元缩氨基硫脲与二水合醋酸锌的量比为1:0.6,甲醇为溶剂,温度65℃,时间6h,茶皂苷元缩氨基硫脲锌配合物产率72.1%,纯度90%。对3种自由基的清除能力强于茶皂苷元,与Keap1-Nrf2有显著的相互作用。茶皂苷元缩氨基硫脲及其锌配合物改善了茶皂苷元的活性,可以增强机体的抗氧化能力。 相似文献
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《精细与专用化学品》2017,(6)
对海燕皂苷P1的分离纯化及海燕总皂苷的制备方法进行了研究。海燕经70%乙醇进行提取,石油醚、乙酸乙酯、正丁醇梯度萃取,经多种柱色谱对海星正丁醇层部分进行分离纯化,结合理化常数的测定和核磁共振光谱,鉴定了化合物结构为海燕皂苷P1(5’-O-硫酸酯24(-3-O-甲基-L-阿拉伯呋喃糖基)-5-胆甾-3,6,8,15-24-五醇),并采用闪式萃取结合热回流提取法制备海燕总皂苷,其适宜提取条件为以甲醇作为溶剂,闪式破碎5min,甲醇浓度100%,料液比1∶50(即1g海燕加入50mL提取液),加热回流时间1.5h。 相似文献
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皂苷提取纯化及其抗氧化活性的研究进展 总被引:1,自引:0,他引:1
皂苷是一种重要的天然产物,与水混合振摇时可生成持久性的似肥皂泡沫状物,具有很强的抗氧化性,即任何以低浓度存在就能有效抑制自由基的氧化反应。高纯度的皂苷有利于皂苷的抗氧化性的研究。本文对皂苷提取纯化和其抗氧化性方面的研究报道进行了综述,总结了9种提取方法和5种纯化方法,并说明优缺点。对抗氧性的测定方法和影响因素进行总结。 相似文献
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由于IIR具有良好的气密性 ,透气率仅为NR的 1 / 1 0 ,是制造自行车内胎的良好材料 ,欧美等发达国家均采用IIR制造自行车内胎 ,而国内仍以NR内胎为主。为赶上国际先进水平 ,提高产品档次 ,增加新的经济增长点 ,厦门海燕橡胶股份有限公司购买了具有国内先进水平的IIR力车内胎挤出生产线和接头机。从2 0 0 0年 3月开始试验 ,经技术部门与力车内胎分厂几个月的攻关 ,开发出 2 8× 1 12 ,2 6×1 38,2 4× 1 38,2 4× 1 75等规格IIR内胎。目前生产工艺稳定 ,产品外观合格率超过原部颁标准 ,产品质量超过国家标准 ,达到国内先进厂… 相似文献
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Natasja de Bruin Ann-Kathrin Schneider Philipp Reus Sonja Talmon Sandra Ciesek Denisa Bojkova Jindrich Cinatl Imran Lodhi Bruce Charlesworth Simon Sinclair Graham Pennick William F. Laughey Philip Gribbon Aimo Kannt Susanne Schiffmann 《International journal of molecular sciences》2022,23(3)
SARS-CoV-2 uses the human cell surface protein angiotensin converting enzyme 2 (ACE2) as the receptor by which it gains access into lung and other tissue. Early in the pandemic, there was speculation that a number of commonly used medications—including ibuprofen and other non-steroidal anti-inflammatory drugs (NSAIDs)—have the potential to upregulate ACE2, thereby possibly facilitating viral entry and increasing the severity of COVID-19. We investigated the influence of the NSAIDS with a range of cyclooxygenase (COX)1 and COX2 selectivity (ibuprofen, flurbiprofen, etoricoxib) and paracetamol on the level of ACE2 mRNA/protein expression and activity as well as their influence on SARS-CoV-2 infection levels in a Caco-2 cell model. We also analysed the ACE2 mRNA/protein levels and activity in lung, heart and aorta in ibuprofen treated mice. The drugs had no effect on ACE2 mRNA/protein expression and activity in the Caco-2 cell model. There was no up-regulation of ACE2 mRNA/protein expression and activity in lung, heart and aorta tissue in ibuprofen-treated mice in comparison to untreated mice. Viral load was significantly reduced by both flurbiprofen and ibuprofen at high concentrations. Ibuprofen, flurbiprofen, etoricoxib and paracetamol demonstrated no effects on ACE2 expression or activity in vitro or in vivo. Higher concentrations of ibuprofen and flurbiprofen reduced SARS-CoV-2 replication in vitro. 相似文献
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以牛胸腺和猪胸腺为原料,利用饱和(NH4)2SO4沉淀、超滤和层析技术,获取淋巴细胞增殖抑制因子。提取物分子量在10KDa左右,对人T淋巴细胞增殖反应具有明显的抑制作用,平均抑制率达77.63±9.37%,对自然杀伤细胞的细胞毒活性无明显影响。提示所提取的淋巴细胞增殖抑制因子对T细胞增殖抑制具有相对特异性。 相似文献
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Protein by-products from the extraction of lecithin from egg yolk can be converted into value-added products, such as bioactive hydrolysates and peptides that have potential health enhancing antioxidant, and antihypertensive properties. In this study, the antioxidant and angiotensin converting enzyme (ACE) inhibitory activities of peptides isolated and purified from egg yolk protein were investigated. Defatted egg yolk was hydrolyzed using pepsin and pancreatin and sequentially fractionated by ultrafiltration, followed by gel filtration to produce egg yolk gel filtration fractions (EYGF). Of these, two fractions, EYGF-23 and EYGF-33, effectively inhibited the peroxides and thiobarbituric acid reactive substance (TBARS) in an oxidizing linoleic acid model system. The antioxidant mechanism involved superoxide anion and hydroxyl radicals scavenging and ferrous chelation. The presence of hydrophobic amino acids such as tyrosine (Y) and tryptophan (W), in sequences identified by LC-MS as WYGPD (EYGF-23) and KLSDW (EYGF-33), contributed to the antioxidant activity and were not significantly different from the synthetic BHA antioxidant. A third fraction (EYGF-56) was also purified from egg yolk protein by gel filtration and exhibited high ACE inhibitory activity (69%) and IC50 value (3.35 mg/mL). The SDNRNQGY peptide (10 mg/mL) had ACE inhibitory activity, which was not significantly different from that of the positive control captopril (0.5 mg/mL). In addition, YPSPV in (EYGF-33) (10 mg/mL) had higher ACE inhibitory activity compared with captopril. These findings indicated a substantial potential for producing valuable peptides with antioxidant and ACE inhibitory activity from egg yolk. 相似文献
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对柚子不同部位进行类黄酮的提取,同时对柚子类黄酮提取液的抗氧化活性进行了研究。结果表明:柚果皮中类黄酮的含量较柚果肉中类黄酮的含量要高。柚类黄酮提取液具有明显的清除羟自由基和超氧阴离子自由基作用,清除率与浓度之间存在着量效关系。柚类黄酮抗氧自由基的能力强于VC,证明了柚类黄酮是一种很强的抗氧化剂。 相似文献
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对花椒提取物在化妆品中的抗菌活性进行了研究,并将其应用于化妆品配方体系中,与目前市售防腐剂进行了抗菌对比试验。结果表明花椒提取物具有良好的抗菌活性,可作为化妆品防腐剂使用,为其以后在化妆品行业中的应用提供依据。 相似文献