期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
区域选择性地电化学氧化自由基参与的邻位-(4+2)/原位-(3+2)环化
1
作者 关志朋 杨东锋 +7 位作者 刘钊 朱书祥 仲星星 王华敏 李向伟 戚孝天 易红 雷爱文 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2023年第9期144-153,共10页
碳环化合物,特别是五元环和六元环骨架,广泛存在于天然产物和生物活性分子中.Diels-Alder环加成反应是构建这些功能型分子的有效方法,但其底物适用范围有限,且反应条件(如热、微波和过渡金属的使用)苛刻,限制了该方法的应用.自由基物种... 碳环化合物,特别是五元环和六元环骨架,广泛存在于天然产物和生物活性分子中.Diels-Alder环加成反应是构建这些功能型分子的有效方法,但其底物适用范围有限,且反应条件(如热、微波和过渡金属的使用)苛刻,限制了该方法的应用.自由基物种含有不成对的价电子,表现出高活性,在温和的反应条件下提供了新的反应途径.因此,自由基介导的反应为复杂环状分子的合成提供了一个新平台.然而,如何实现选择性自由基环化仍然是一个挑战.鲍德温规则为自由基物种与烯烃炔烃的加成提供了指导,研究人员设计并开发了一系列反应模式构建所需的五元和六元环分子.但是,自由基物种,特别是烷基和烯基与芳基之间选择性的邻位原位环化仍然不明确.本文利用苄基丙二酸酯为自由基源,烯烃和炔烃分别为自由基受体,分别获得烷基和烯基自由基中间体,并探究烷基自由基和烯基自由基与芳基之间的选择性环化.利用二茂铁介导的电化学氧化策略,进行了烷基/烯基自由基与芳基的选择性环化实验.结果表明,烷基自由基与芳环发生选择性邻位-(4+2)环化,烯基自由基与芳环发生选择性原位-(3+2)环化.理论研究结果表明,促进烯烃优先邻位加成的主要原因是有利的相互作用能;炔烃优先原位加成区域选择性由形变能量控制.重要的是,该策略被认为是鲍德温自由基环化规则的重要补充.此外,对二茂铁介导的电化学氧化苄基丙二酸酯的C-H键官能团化进行了深入的机理研究.自由基捕获实验证明了苄基丙二酸酯碳自由基的存在.循环伏安测试结果表明,苄基丙二酸酯碳负离子与二茂铁之间存在电子转移.阳极电势实验证明了二茂铁在该自由基反应中的作用;同位素实验揭示了螺环化合物氧的来源.本文合成了一系列四氢萘和螺环衍生物,表现出较好的底物适用范围和官能团耐受性,且该方法避免了化学氧化剂/碱/贵金属的使用、底物的预官能团化以及底物的过氧化.综上,本文为实现自由基的区域选择性环化提供了参考. 展开更多
关键词 区域选择性 自由基 邻位-(4+2)/原位-(3+2)环化 电化学氧化 碳环化合物
下载PDF
Hypoxia response element-directed expression of bFGF in dental pulp stem cells improve the hypoxic environment by targeting pericytes in SCI rats 被引量:2
2
作者 Sipin Zhu Yibo Ying +13 位作者 Yan He xingxing zhong Jiahui Ye Zhiyang Huang Min Chen Qiuji Wu Yifan Zhang Ziyue Xiang Yurong Tu Weiyang Ying Jian Xiao Xiaokun Li Qingsong Ye Zhouguang Wang 《Bioactive Materials》 SCIE 2021年第8期2452-2466,共15页
Cell-based transplantation strategies possess great potential for spinal cord injury(SCI)repair.Basic fibroblast growth factor(bFGF)has been reported to have multiple neuro-promoting effects on developing and adult ne... Cell-based transplantation strategies possess great potential for spinal cord injury(SCI)repair.Basic fibroblast growth factor(bFGF)has been reported to have multiple neuro-promoting effects on developing and adult nervous system of mammals and considered a promising therapy for nerve injury following SCI.Human dental pulp stem cells(DPSCs)are abundant stem cells with low immune rejection,which can be considered for cell replacement therapy.The purpose of this study was to investigate the roles of DPSCs which express bFGF under the regulation of five hypoxia-responsive elements(5HRE)using an adeno-associated virus(AAV-5HRE-bFGF-DPSCs)in SCI repairing model.In this study,DPSCs were revealed to differentiate into CD13^(+)pericytes and up-regulate N-cadherin expression to promote the re-attachment of CD13^(+)pericytes to vascular endothelial cells.The re-attachment of CD13^(+)pericytes to vascular endothelial cells subsequently increased the flow rate of blood in microvessels via the contraction of protuberance.As a result,increased numbers of red blood cells carried more oxygen to the damaged area and the local hypoxia microenvironment in SCI was improved.Thus,this study represents a step forward towards the potential use of AAV-5HRE-bFGF-DPSCs in SCI treatment in clinic. 展开更多
关键词 Spinal cord injury Adeno-associated virus Basic fibroblast growth factor Dental pulp stem cell Vascular regulation Hypoxic microenvironment
原文传递
Myocardial protection by heparin-based coacervate of FGF10 被引量:2
3
作者 Zhouguang Wang Yan Huang +5 位作者 Yan He Sinan Khor xingxing zhong Jian Xiao Qingsong Ye Xiaokun Li 《Bioactive Materials》 SCIE 2021年第7期1867-1877,共11页
Heart disease is still the leading killer all around the world,and its incidence is expected to increase over the next decade.Previous reports have already shown the role of fibroblast growth factor10(FGF10)in allevia... Heart disease is still the leading killer all around the world,and its incidence is expected to increase over the next decade.Previous reports have already shown the role of fibroblast growth factor10(FGF10)in alleviating heart diseases.However,FGF10 has not been used to treat heart diseases because the free protein has short half-life and low bioactivity.Here,an injectable coacervate was designed to protect growth factor from degradation during delivery and the effects of the FGF10 coacervate were studied using a mice acute myocardial infarction(MI)model.As shown in our echocardiographic results,a single injection of FGF10 coacervate effectively inhibited preserved cardiac contractibility and ventricular dilation when compared with free FGF10 and the saline treatment 6 weeks after MI.It is revealed in histological results that the MI induced myocardial inflammation and fibrosis was reduced after FGF10 coacervate treatment.Furthermore,FGF10 coacervate treatment could improve arterioles and capillaries stabilization through increasing the proliferation of endothelial and mural cells.However,with the same dosage,no statistically significant difference was shown between free FGF10,heparin+FGF10 and saline treatment,especially in long term.On another hand,FGF10 coacervate also increased the expression of cardiac-associated the mRNA(cTnT,Cx43 and α-SMA),angiogenic factors(Ang-1 and VEGFA)and decreased the level of inflammatory factor(tumor necrosis factor-α).The downstream signaling of the FGF10 was also investigated,with the western blot results showing that FGF10 coacervate activated the p-FGFR,PI3K/Akt and ERK1/2 pathways to a more proper level than free FGF10 or heparin+FGF10.In general,it is revealed in this research that one-time injection of FGF10 coacervate sufficiently attenuated MI induced injury when compared with an equal dose of free FGF10 or heparin+FGF10 injection. 展开更多
关键词 Fibroblast growth factor-10 ANGIOGENESIS Controlled release Myocardial infarction COACERVATE
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部