首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   13篇
  免费   1篇
  国内免费   5篇
化学   19篇
  2020年   2篇
  2019年   1篇
  2018年   1篇
  2016年   1篇
  2012年   1篇
  2011年   2篇
  2010年   1篇
  2009年   2篇
  2006年   5篇
  2002年   2篇
  1994年   1篇
排序方式: 共有19条查询结果,搜索用时 31 毫秒
1.
分子印迹壳聚糖膜和柚皮苷模板分子间相互作用的研究   总被引:2,自引:0,他引:2  
以壳聚糖为膜材料,以柚皮苷为模板分子,通过硫酸交联在水相中制备了水相识别柚皮苷分子印迹壳聚糖膜。通过高效液相色谱(HPLC)、紫外光谱(UV)和红外光谱(FT-IR)初步研究了模板分子和功能单体之间的相互作用,表明体系产生了新的氢键。  相似文献   
2.
高效液相色谱法测定福丽生发液中柚皮甙的含量李文莉,梁建国(湖南省药品检验所长沙410001)1前言福丽生发液是一种治疗脂溢性脱发、斑秃等症的新药,因其疗效显著而被广泛应用,并已进入国际市场。根据骨碎补是其主要药味之一,而它的有效成分柚皮甙有杀菌、消炎...  相似文献   
3.
高效液相色谱法测定柑橘汁中的柠檬苦素和柚皮苷   总被引:9,自引:0,他引:9  
陈静  高彦祥  吴伟莉  李绍振 《色谱》2006,24(2):157-160
柑橘汁的苦味主要是由于柚皮苷和柠檬苦素的存在所致,其含量的测定可用于控制柑橘类果汁的质量。采用高效液相色谱法在KR100-5C18(4.6 mm i.d.×250 mm,5 μm)上,分别以乙腈-四氢呋喃-水(体积比为17.5∶17.5∶65)和甲醇-冰醋酸-水(体积比为40∶1∶59)为流动相(流速均为1 mL/min),在207 nm和283 nm检测波长下分别测定了柠檬苦素和柚皮苷。实验结果表明,柠檬苦素在1.00~50.00 mg/L时线性关系良好(r=0.9992),检出限为0.07 μg,平均加标回收率为98.69%,相对标准偏差(RSD)为2.5%;柚皮苷在20.00~160.00 mg/L时线性关系良好(r=0.9988),检出限为0.14 μg,平均加标回收率为100.13%,RSD为1.5%。用该法检测柑橘汁样品中的柠檬苦素与柚皮苷,方法简便、快速、准确。  相似文献   
4.
《先进技术聚合物》2018,29(1):470-480
The flavonoid‐based macromolecule initiator was prepared for the first time by the transesterification reaction of naringin with 2‐bromoisobutyryl bromide. In accordance with the “grafting from” methodology, a naringin‐based copolymer brush with a polar naringenine‐7‐rhamnosidoglucoside core and an amphiphilic poly(methyl methacrylate)‐block‐poly(N‐isopropylacrylamide) (PMMA‐b‐PNIPAM) side chains was synthesized for the first time via a simplified electrochemically mediated ATRP (seATRP), utilizing only 40 ppm of catalytic complex. The rate of the polymerizations was controlled by applying optimal potential or current values during preparative electrolysis to prevent the possibility of intermolecular coupling of the growing polymer brushes. Naturally derived polymer brushes showed narrow molecular weight distributions (Đ = 1.06−1.08). 1H NMR spectral results confirm the formation of citrus‐based polymer brushes. These new naringin‐based polymer materials may find biomedical applications as thermo‐sensitive drug delivery systems, membranes, and biologically active thin films in tissue engineering.  相似文献   
5.
儿童指画印泥样品用甲醇与0.02mol·L^-1磷酸二氢钾溶液以体积比3∶7组成的混合液超声萃取20min,冷却至室温,于16 000r·min^-1转速下离心15min,取上清液过0.22μm过滤膜过滤,采用超高效液相色谱法测定滤液中柚皮苷和苯甲酸地那铵的含量。以C18色谱柱为分离柱,用乙腈和pH 4.3的0.02mol·L^-1磷酸二氢钾溶液以不同比例混合的溶液为流动相进行梯度洗脱,用二极管阵列检测器测定。柚皮苷和苯甲酸地那铵的质量浓度均在0.1~5.0mg·L^-1内与其对应的峰面积呈线性关系,检出限(3S/N)依次为0.75,1.15mg·kg^-1。以空白样品为基体进行加标回收试验,所得回收率为73.5%~104%,测定值的相对标准偏差(n=6)为4.2%~6.6%。  相似文献   
6.
The aims of this study were to prepare different sizes of electrospun naringin‐loaded microspheres (Ng‐ms) and investigate the effects of the particle size of these microspheres on drug release from naringin‐loaded microsphere/sucrose acetate isobutyrate (Ng‐m‐SAIB) hybrid depots to develop an improved drug delivery system for tissue engineering. Different sizes of microspheres were produced using electrospray methods by controlling electrospinning parameters. The Ng‐m‐SAIB depots were prepared by dispersing Ng‐ms in SAIB depots. The morphology and size distributions of the electrospun Ng‐ms were characterized by polarizing microscopy and scanning electron microscopy (SEM). To better understand the release behavior of Ng‐m‐SAIB, the porosity of SAIB depots was measured. Consequently, both small (2.51 ± 0.191 μm) and large (5.03 ± 0.172 μm) microspheres exhibited smooth surfaces and good monodispersity. The initial and long‐term drug release rates of the large microspheres were lower than those of small microspheres. On the first day after 2.5‐μm and 5‐μm Ng‐m‐SAIB depots were produced, the burst release reduced dramatically from 68.79% to 3.30% and from 63.20% to 0.00%, respectively. After 92 days of release, the drug release rate of 5‐μm Ng‐m‐SAIB was still lower than that of 2.5‐μm Ng‐m‐SAIB, with values of 58.54% and 63.93%, respectively. These results demonstrate that drug release from Ng‐m‐SAIB depots can be tailored solely by varying the size of the microspheres and that good drug release behavior occurred.  相似文献   
7.
柚皮苷半合成生物活性黄酮醇和橙酮类化合物研究   总被引:1,自引:0,他引:1  
吴峥  蔡双莲  范文金  汪秋安 《有机化学》2012,32(7):1296-1302
以柚皮苷为原料,经过糖苷水解、脱氢、苄基保护、O-甲基化、过氧丙酮(DMDO)氧化或阿尔格-弗林-大山田(Algar-Flynn-Oyamada)反应和脱苄基保护等反应步骤,半合成了山萘酚(1,Kaemferol),5,7,4’-三甲氧基黄酮醇(2)、3,5-二羟基-7,4’-二甲氧基黄酮醇(3),鼠李柠檬素(4,Rhamnocitrin)等4种天然黄酮醇类和4,6,4’-三羟基二氢橙酮(5)、4-羟基-6,4’-二甲氧基二氢橙酮(6)两种新的橙酮类化合物.重点探讨了过氧丙酮(DMDO)直接氧化黄酮制备黄酮醇和Algar-Flynn-Oyamada反应制备橙酮的合成方法,改进优化了反应条件.所有合成化合物的结构已通过1H NMR,MS和IR等波谱方法进行了确认.该合成途径原料易得,工艺简便,收率较高,具有较高的应用价值.  相似文献   
8.
建立了固相萃取-高效液相色谱检测饲料中新橙皮苷二氢查耳酮(NHDC)和柚皮苷二氢查耳酮(Naringin DC)的方法。采用纯甲醇溶液进行超声辅助萃取样品,经HLB固相萃取柱净化后在XB-C18(150 mm×4.6 mm,5 μm)色谱柱上分离,用甲醇/水作为流动相进行梯度洗脱,光电二极管阵列检测器进行检测。结果表明,新橙皮苷二氢查耳酮和柚皮苷二氢查耳酮在0.2~49.0 mg/L范围内具有良好的线性关系,相关系数均>0.999,定量限分别为0.02和0.01 mg/kg。日内和日间精密度分别为0.7%~4.1%和0.9%~6.0%。方法的加标回收率为86.2%~105.0%,相对标准偏差(RSDs)为1.0%~6.3%(n=3)。该方法能有效降低饲料基体成分的干扰,灵敏度高,重现性好,适用于饲料中新橙皮苷二氢查耳酮和柚皮苷二氢查耳酮的定量检测。  相似文献   
9.
以柚皮苷(NG)为印迹分子, β-环糊精为功能体, 六亚甲基二异氰酸酯为交联剂, 采用乳液聚合法制备了对NG具有特定识别能力的吸附材料: 棒状印迹聚合物. 扫描电镜及比表面分析仪测试结果表明印迹聚合物具有较大的孔隙及比表面积|红外及核磁共振谱研究证实了识别位点来自β-环糊精与NG羟基间的氢键作用. 采用平衡吸附实验方法研究了聚合物的吸附性能和选择性能. 实验结果表明, 棒状印迹聚合物(RMIP)对NG具有较高的亲和性和选择性. Scatchard分析表明, MIP在识别NG过程中存在2类结合位点: KD1=0.016 mmol/L, Bmax1=15.31 μmol/g, KD2=0.24 mmol/L, Bmax2=98.41 μmol/g. 当NG浓度为 0.02 mg/mL时, MIP及相应NIP对 NG的分配系数 KD 分别为4.38和2.86, 印迹因子α为1.53.  相似文献   
10.
Study on Adsorption and Separation of Naringin with Macroporous Resin   总被引:1,自引:0,他引:1  
X-5 resin, with higher adsorption and easier desorption of naringin, was selected from five kinds of macroporous resins through static adsorption and desorption experiments. Effects of concentration, pH value, and flow rate of naringin extract on the adsorption of naringin by X-5 resin were studied. Meanwhile, the effect of these factors on the desorption of naringin from X-5 resin was also investigated. The experimental results show that the adsorption isotherm of naringin by X-5 resin can be described by the Langmuir isotherm equation. The static maximum adsorption capacity of naringin is 32.6 mg/g with naringin concentration at 2.7 g/L, while the dynamic adsorption capacity of naringin is 23.8 mg/g with naringin extract flow rate at two times that of resin volume per hour. The optimal eluant is 60% (v/v) ethanol-water with pH value of 10. The desorption ratio will rise to more than 85% when the flow rate of this optimal eluant is one to two times that of resin volume per hour. Translated from Journal of Central South University (Science and Technology)  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号