Acid–base equilibrium of puerarin in CTAB micelles

Preparation and properties of Pue-loaded HA-ADH-PS nanomicelles

Puerarin (Pue) is the most abundant isoflavonoid in kudzu root. It has been widely used as a therapeutic agent for the treatment of cardiovascular diseases. However, poor-bioavailability of puerarin is the main obstacle to its widespread clinical applications. In this paper, HA-ADH-PS nanomicelles were prepared by chemical modification, noncovalent modification and etc, and characterized by means of FT-IR, ultraviolet (UV) and thermogravimetric analysis (TG). The encapsulation efficiency and drug loading of Pue-loaded HA-ADH-PS nanomicelles were 45.1% and 19.89% by UV, respectively. It could be observed from the transmission electron microscopy (TEM) images that HA-ADH-PS micelles appeared obvious spherical structure in the water. The particle size of HA-ADH-PS nanomicelles and Pue-loaded HA-ADH-PS nanomicelles were about 136.8 nm and 119.5 nm with a PDI of 0.237 and 0.272, respectively. The fluorescence probe method was used to characterize the critical micelle concentration, the critical micelle concentration (CMC) value of the nanomicells was 0.002 g/L and the results met the requirements and ensured the stability of micelles after dilution. DPPH assay suggested that Pue-loaded HA-ADH-PS nanomicelles had an obvious radical scavenging effect in vitro. MTT test showed that Pue-loaded HA-ADH-PS nanomicelles was non-toxic and had good biocompatibility. Thus, Pue-loaded HA-ADH-PS nanomicelles could be used as a potential drug carrier for puerarin.

Furosemide–Cetyltrimethylammonium Bromide Interactions in Aqueous Dimethylsulfoxide Solutions: Physico–Chemical Studies

Interaction of a cardiovascular drug, Furosemide with cetyltrimethylammonium bromide (CTAB) has been studied in aqueous solutions of Dimethylsulfoxide (DMSO) with the help of density, speed of sound and conductivity measurements over a range of temperatures 293.15–313.15 K at interval of 5 K. The interaction parameters viz. apparent molar volume, Vϕ and apparent molar isentropic compression, κs , ϕ have been enumerated from density and speed of sound data. Also, variation in the micellization behavior has been explored by calculating critical micelle concentration, CMC. It has been observed that micellization tendency of the surfactant decreases in the presence of DMSO as compared to pure aqueous system. Moreover, the CMC values shift toward lower concentration with increase in Furosemide content because of increase in hydrophobic hydration which may be to hydrophobicity of drug molecule. The dependence of CMC in mole fraction (Xcmc ) values on the temperature has been analyzed in terms of thermodynamics of the system by reporting the standard thermodynamic parameters i.e. standard Gibb’s free energy ( Δ G m o ) , $(\Delta G_m^o),$ enthalpy ( Δ H m o ) $(\Delta H_m^o)$ and entropy ( Δ S m o ) $(\Delta S_m^o)$ of micellization for CTAB in mixed solvent systems. The entropies of micellization are all positive, and they compensate the enthalpies of the process. Compensation temperature, Tc has also been evaluated from enthalpy–entropy compensation whose values lies in Lumrys range (270–300 K).

Studies on the interaction of 2-amino-3-hydroxy-anthraquinone with surfactant micelles reveal its nucleation in human MDA-MB-231 breast adinocarcinoma cells

Structural, spectroscopic and biochemical studies on 2-amino-3-hydroxy-anthraquinone (AQ) were carried out.

Binding of puerarin to human serum albumin: a spectroscopic analysis and molecular docking

Puerarin is a widely used compound in Chinese traditional medicine and exhibits many pharmacological activities. Binding of puerarin to human serum albumin (HSA) was investigated by ultraviolet absorbance, fluorescence, circular dichroism and molecular docking. Puerarin caused a static quenching of intrinsic fluorescence of HSA, the quenching data was analyzed by Stern-Volmer equation. There was one primary puerarin binding site on HSA with a binding constant of 4.12 x 10(4) M(-1) at 298 K. Thermodynamic analysis by Van Hoff equation found enthalpy change (DeltaH(0)) and entropy change (DeltaS(0)) were -28.01 kJ/mol and -5.63 J/mol K respectively, which indicated the hydrogen bond and Van der Waas interaction were the predominant forces in the binding process. Competitive experiments showed a displacement of warfarin by puerarin, which revealed that the binding site was located at the drug site I. Puerarin was about 2.22 nm far from the tryptophan according to the observed fluorescence resonance energy transfer between HSA and puerarin. Molecular docking suggested the hydrophobic residues such as tyrosine (Tyr) 150, Tyr 148, Tyr 149 and polar residues such as lysine (Lys) 199, Lys 195, arginine 257 and histidine 242 played an important role in the binding reaction.