基于己二胺修饰荧光碳点的中药大黄素检测研究

以己二胺为表面修饰剂,水热法合成荧光碳点。利用红外光谱、紫外-可见吸收光谱和荧光光谱研究了碳点与大黄素之间的相互作用。基于大黄素在p H 8.8的PBS缓冲溶液中对合成碳点的荧光猝灭效应,建立一种简便灵敏的测定大黄素的方法。此方法中减弱的荧光强度与大黄素浓度在1.352~21.63 mg/L范围内呈线性关系,检出限为0.906 9 mg/L。     

Surface enhanced fluorescence of anti-tumoral drug emodin adsorbed on silver nanoparticles and loaded on porous silicon

Fluorescence spectra of anti-tumoral drug emodin loaded on nanostructured porous silicon have been recorded. The use of colloidal nanoparticles allowed embedding of the drug without previous porous silicon functionalization and leads to the observation of an enhancement of fluorescence of the drug. Mean pore size of porous silicon matrices was 60 nm, while silver nanoparticles mean diameter was 50 nm. Atmospheric and vacuum conditions at room temperature were used to infiltrate emodin-silver nanoparticles complexes into porous silicon matrices. The drug was loaded after adsorption on metal surface, alone, and bound to bovine serum albumin. Methanol and water were used as solvents. Spectra with 1 μm spatial resolution of cross-section of porous silicon layers were recorded to observe the penetration of the drug. A maximum fluorescence enhancement factor of 24 was obtained when protein was loaded bound to albumin, and atmospheric conditions of inclusion were used. A better penetration was obtained using methanol as solvent when comparing with water. Complexes of emodin remain loaded for 30 days after preparation without an apparent degradation of the drug, although a decrease in the enhancement factor is observed. The study reported here constitutes the basis for designing a new drug delivery system with future applications in medicine and pharmacy.     

Study on the electrochemical behaviour of the anticancer herbal drug emodin

The electrochemical behaviour of the anticancer herbal drug emodin was investigated by cyclic voltammetry (CV) at glassy carbon electrode. In 0.05 M NH₃-NH₄Cl (50% ethanol, pH 7.2) buffer solution, a pair of quasi-reversible redox peaks at potentials of Ep1 = −0.688 V and Ep2 = −0.628 V and one irreversible anodic peak, which was a typical anodic peak of emodin, at Ep3 = −0.235 V appeared at a scan rate of 100 mV/s. The irreversible anodic peak currents are linearly related to the emodin concentrations in a range from 8.9 × 10⁻⁸ M to 7.8 × 10⁻⁶ M with a pre-concentration time of 80 s under −0.620 V. Using the established method without pretreatment and pre-separation, emodin in herbal drug was determined with satisfactory results. Moreover, the electrode process dynamics parameters were also investigated by electrochemical techniques.     

Preparation of Emodin‐Polyethylene Glycol Composite Microparticles Using a Supercritical Antisolvent Process

Emodin‐polyethylene glycol (PEG) composite microparticles were obtained from a dichloromethane‐methanol mixture via the solution‐enhanced dispersion by supercritical fluids through prefilming atomization (SEDS‐PA) process. Morphologies, particle sizes (PSs), and emodin contents of the composite microparticles were analyzed by scanning electron microscopy and UV‐visible spectrophotometry. The crystallinity change of emodin before and after the SEDS‐PA process was demonstrated by X‐ray powder diffraction (XRD). The composite microparticles present nubbly, rod‐like emodin dispersed in PEG or a nubbly, sheet emodin inlay on PEG, with PSs ranging between 3 and 12 μm. The PSs of the composite microparticles increase with the increase of temperature, decrease with the increase of pressure, and do not seem to depend on the emodin content of the initial solute and on the solution flow rate. The emodin contents of the composite microparticles increase with the increasing emodin content in the initial solute and temperature and decrease with increasing solution flow rate.     

HPLC法测定保健食品中蒽醌类成分的含量

目的建立测定保健食品中大黄酸、芦荟大黄素、1,8-二羟基蒽醌、大黄素、大黄酚、大黄素甲醚含量的高效液相色谱法。方法使用Symmetry@C18(250mm×4.6mm,5μm)为色谱柱,以甲醇+0.1%磷酸水溶液(80+20)为流动相,检测波长为254nm。结果大黄酸、芦荟大黄素、1,8-二羟基蒽醌、大黄素、大黄酚、大黄素甲醚在0.014～0.280、0.014～0.280、0.0126～0.0252、0.0156～0.104、0.025～0.500和0.025～0.500μg/ml浓度范围内具有良好线性关系;平均加标回收率分别为91.5%、90.2%、85.3%、105.3%、87.7%和102.1%;相对标准偏差分别为6.21%、5.82%、7.11%、8.50%、7.35%和9.42%。结论该方法简便、准确,有良好的重现性,技术参数指标符合食品理化分析的要求,可用于蒽醌类保健食品的质量控制。     

虎杖有效成份的开发现状及展望

本文分析了虎杖的化学成分 ,并对其有效成分白藜芦醇 (白藜芦醇甙 )、大黄素、虎杖黄色素的功能、提取及利用情况进行了探讨。     

高效液相色谱法测定胆清胶囊中大黄素含量的研究

采用高效液相色谱法，对制剂中大黄所含大黄素的含量测定进行了方法研究。实验结果表明，本法快速、简便、回收率高，结果准确可靠。     

高效液相色谱法测定八正泡腾片中大黄素的含量

目的建立八正泡腾片质量标准的含量测定项目。方法采用高效液相色谱法测定八正泡腾片中大黄素的含量,色谱柱为Dikma C18(250mm×4.6mm,5μm),流动相为甲醇-0.1%磷酸溶液(85:15),检测波长为290nm,流速为1mL·min-1,柱温为40℃。结果大黄素的线性范围为0.04992～0.3328μg(r=0.9999),平均回收率为100.88%(n=6,RSD=2.02%)。结论高效液相色谱法简便、准确,可以有效控制八正泡腾片的质量。     

反相高效液相色谱法同时测定洁康舒洗剂中三组分的含量

建立反相高效液相色谱法同时测定洁康舒洗剂中大黄酸、大黄素和大黄酚含量的方法。采用反相高效液相色谱法。symmctry C18柱(3.9×150mm,5μm)流动相为甲醇—水—磷酸(80:20:0.1);流速为1.0mL·min-1;检测波长为432nm。大黄酸、大黄素和大黄酚的回归方程分别为:C1=7.3159×10-1+1.8966×10-5A,r=9994,C2=1.0513+1.5680×10-5A,r=0.9999C3=1.2260-1.4684×10-5A,r=0.9999三者分别在7.60~38.0μg·mL-1、1.75~8.75μg·mL-1、2.4~12.OOμg·mL-1范围内呈线性关系。平均回收率和RSD分别为98.02%、96.63%、97.05%和1.78%、1.20%、1.15%。该方法操作简便,测定结果准确可靠,可用于测定洁康舒洗剂中大黄酸、大黄素和大黄酚的含量。     

Supercritical fluid extraction of piceid, resveratrol and emodin from Japanese knotweed

In the present study, the use of supercritical fluid extraction was investigated for selected compounds from the plant Japanese knotweed (Polygonum cuspidatum Siebold & Zucc.). The effects of parameters such as type of modifier, pressure, temperature and time on the extraction efficiency of piceid, resveratrol and emodin were studied. The optimal conditions were found as follows: modifier acetonitrile, 40 MPa, 100 °C and 45 min. SFE results were compared with those obtained by conventional Soxhlet extraction carried out for 4 h. The extracts obtained using these two techniques were analysed by liquid chromatography coupled with UV detection. LiChrospher^® 100, RP-18 column (125 mm × 4 mm, 5 μm) coupled with gradient elution acetonitrile in acidified water was used for the separation of compounds at flow rate 0.5 mL min⁻¹. Detection was carried out at 306 nm. Limits of detection were 21, 8 and 52 μg L⁻¹ for piceid, resveratrol and emodin, respectively. The linear range was 0.5-10 mg L⁻¹ for piceid and resveratrol, and 1-50 mg L⁻¹ for emodin with correlation coefficients above 0.9981. Based on the comparison of both methods extracted amount of piceid by Soxhlet extraction is approximately 10 times higher than by SFE method, while the extraction yield of emodin by Soxhlet extraction in approx. 2.5 times lower than by SFE. The advantage of SFE over Soxhlet extraction method is more than 5 times shorter extraction time period.