基于2-羟丙基-β-环糊精修饰的CdTe荧光探针定量分析结晶紫及机理探讨

在稳定剂巯基乙酸(TGA)和修饰剂2-羟丙基-β-环糊精(2-Hp-β-CD)存在下,获得的2-Hp-β-CDCdTe量子点具有高的荧光强度、水溶性和光稳定性,以及对结晶紫(CV)的良好包含能力。利用紫外-可见吸收光谱、荧光光谱及TEM图谱,研究了2-Hp-β-CDCdTe量子点与CV的相互作用情况。通过十六烷基三甲基溴化铵(CTAB)作用,显著降低了供体与受体之间的距离,促使量子点与结晶紫发生能量转移,且量子点的荧光光谱与CV的吸收光谱有效重叠,据此建立了量子点与CV的荧光共振能量转移(FRET)体系,并用于CV含量的测定。结果表明,在pH 8.0的Tris-HCl缓冲液中,当存在CTAB时,CV能对2-Hp-β-CDCdTe量子点的荧光峰发生猝灭,且CV浓度在1.0×10^-7~1.0×10^-5 mol/L范围内与量子点的荧光强度变化(ΔF)呈良好线性关系(r^2=0.9952),检出限为1.74×10^-8 mol/L,平均回收率为99.0%~106%。

Increased stability and solubility of dihydroartemisinin in aqueous solution through the formation of complexes with 2-hydroxypropyl-β-cyclodextrin

The effect of various concentrations of 2-hydroxypropyl-β-cyclodextrin （HP-β-CD） on the solubility of dihydroartemisinin （DHA） in aqueous solution at different pHs was investigated. The influence of different concentrations of 2-hydroxypropyl-β- eyclodextrin on the stability of dihydroartemisinin at 50, 60, 70 and 80 ℃ was also studied. Inclusion complex of dihydroartemisinin with 2-hydroxypropyl-β-cyclodextrin was prepared and characterized by X-ray diffraction and differential scanning calorimetry. The 2-hydroxypropyl-β-cyclodextrin effectively inhibited the hydrolysis of dihydroartemisinin and greatly increased its solubility. Furthermore, we showed that the higher concentrations of 2-hydroxypropyl-β-cyclodextrin, the better stability and solubility of dihydroartemisinin. When the temperature was increased, the stability of dihydroartemisinin decreased. Our results indicated that 2-hydroxypropyl-β-cyclodextrin can be used as a stabilizer and solubilizer of dihydroartemisinin.

Gallic Acid/2-Hydroxypropyl-β-cyclodextrin Inclusion Complexes Electrospun Nanofibrous Webs:Fast Dissolution,Improved Aqueous Solubility and Antioxidant Property of Gallic Acid

Gallic acid(GA)is a kind of natural polyphenolic compound,but its low aqueous solubility restricts its application in the fields of food and medicine.Cyclodextrin can form inclusion complexes with guest molecules(e.g.,essential oils,food supplements)through cavities with special properties to improve aqueous solubility,thermal stability,and bioavailability of guest molecules.In this research,gallic acid/2-hydroxypropyl-β-cyclodextrin inclusion complexes(GA/2-HP-β-CD/ICs)were formed in a highly concentrated solution of 2-HP-β-CD.Bead-free and uniform nanofibrous webs(GA/2-HP-β-CD/IC-NWs)were produced successfully by electrospun GA/HP-β-CD/IC aqueous solution.The initial molar ratio(GA:2-HP-β-CD=1:1)of GA/2-HP-β-CD/IC in the solutions was largely maintained in GA/2-HP-β-CD/IC-NW.The aqueous solubility of GA was enhanced and GA/2-HP-β-CD/IC-NW has displayed fast dissolution property.Furthermore,in comparison with GA powder,GA/2-HP-β-CD/IC-NW demonstrated improved antioxidant capacity.The results suggested that GA/2-HP-β-CD/IC-NW have broad application prospects as orally fast dissolution systems for food supplements.

Synthesis of Atrazine-HPCD Inclusion and Its Bioactivity

The inclusion of atrazine with 2-hydroxypropyl-β-cyclodextrin(HPCD) was synthesized by ultrasonic method, and it was characterized by UV, XRD and 1H NMR. The solubility in water and the bioactivity of the inclusion were also studied here. The results indicated that the UV maximum absorption wavelength of the inclusion remained at 223 nm, while its intensity decreased. The XRD peaks of atrazine disappeared, weakened and shifted in the inclusion, and the chemical shift of H-3 and H-5 of cyclodextrin inner cavity led to the upfield. The characterization data showed that the atrazine-HPCD inclusion had already formed. At the same time, the solubility of the atrazineHPCD inclusion in water became 20.08 times as that of atrazine. Moreover, the atrazine-HPCD inclusion had better herbicidal activity. When the concentration of the inclusion was 6.5 mg/mL, the inhibition ratios of the inclusion to taproot length, taproot fresh weight, sprout length and sprout fresh weight of barnyard grass were 66.96%, 57.22%, 70% and 57.53%, respectively, which were all higher than those of atrazine.

A thorough analysis of the effect of surfactant/s on the solubility and pharmacokinetics of (S)-zaltoprofen

Until now, there are no publications about the preformulation studies on(S)-zaltoprofen((S)-ZPF). Hence, we first investigated the solubility of(S)-ZPF, screened solubilizers and performed the pharmacokinetic study of(S)-ZPF in the presence of the solubilizers. The measurement of the solubility of(S)-ZPF in 26 different solvents was carried out, including d-alpha tocopheryl polyethylene glycol 1000 succinate(TPGS), 2-hydroxypropyl-β-cyclodextrin(HPCD), and mixtures of individual solvent. The plasma concentration of(S)-ZPF and the amount of(S)-ZPF retained in stomach were determined after oral(35.0 mg/kg) and intravenous(5.0 mg/kg) administration. The solubility of(S)-ZPF showed an increase of 484-fold in TPGS compared to its aqueous solubility. There was a significant increase of AUC 0-24 h for pure(S)-ZPF in the TPGS group(813.59 ± 64.17 μg h/ml) in comparison with AUC 0-24 h in the HPCD group(595.57 ± 71.76 μg h/ml) and water group(465.57 ± 90.89 μg h/ml). In addition, the T max of(S)-ZPF in the TPGS group was 2 h, much faster than that in the HPCD or water groups(5.50 or 5.67 h, respectively). This suggested that TPGS played a significant role in the increase of solubility and bioavailability of(S)-ZPF.