The interactions between Bovine Serum Albumin (BSA) and three flavonols, galangin, kaempferol and quercetin were studied by means of fluorescence spectroscopy. The fluorescence intensity of BSA exhibits remarkable decrease along with appreciable blue-shift of its maximum emission wavelength upon addition of the three compounds, respectively. The respective binding constant Ka and number of binding sites of each compound were calculated, and the quenching mechanism was proposed. Based on the values of thermodynamic parameters, the binding of each compound proceeds spontaneously with BSA. The binding distance between each and BSA was obtained by Foerster's dipole-dipole non-radiation energy transfer mechanism.

A method of bulk liquid membrane using complex of (S, S)-di-n-dodecyltartrate and boric acid was developed for the enantioselective transport of racemic propranolol. It was shown that l - propranolol can be effectively transported. The enantioselectivity of the complex for a specific propranolol enantiomer in BLM systems is mainly based on kinetics and is not thermodynamically driven. The effects of the concentration ratio of propranolol to chiral carrier and the buffer pH were studied, respectively. An appropriate choice for such concentration ratio and the pH in the aqueous solution result to be 1 : 20 and 5, respectively. The developed method is helpful for optimizing the transport of bulk liquid membrane systems and realizing the large-scale production of pure enantiomer.

Distribution behavior of mandelic acid enantiomers was examined in an aqueous-organic solvent of a two-phase system containing L-tartarate. The influences of pH, length of alkyl chain of L-tartarate, organic solvent, concentration of phosphate salt and time of chiral extraction on partition coefficient (k) and separation factor (α) were investigated, respectively. With the rise of pH, k decreases, but α increases. With the addition of length of alkyl chain of L-tartarate, k and α decrease. The organic solvent and concentration of phosphate salt also have a bigger influence on k and α. A new binary chiral selector system is presented, effective for the enantioselective extraction of racemic mandelic acid. The distribution coefficients of D- and L-mandelic acid as high as 14.9 and 7.0, respectively, and the enantioselectivity value of 2.1 were found.

Phosphatidylserine (PS) exposure occurs during the cell death program and fluorescein-labeled lactadherin permits the detection of PS exposure earlier than annexin V in suspended cell lines. Adherent cell lines were studied for this apoptosis-associated phenomenon to determine if PS probing methods are reliable because specific membrane damage may occur during harvesting. Apoptosis was induced in the human tongue squamous carcinoma cell line (Tca8113) and the adenoid cystic carcinoma cell line (ACC-2) by arsenic trioxide. Cells were harvested with a modified procedure and labeled with lactadherin and/or annexin V. PS exposure was localized by confocal microscopy and apoptosis was quantified by flow cytometry. The detachment procedure without trypsinization did not induce cell damage. In competition binding experiments, phospholipid vesicles competed for more than 95 and 90% of lactadherin but only about 75 and 70% of annexin V binding to Tca8113 and ACC-2 cells. These data indicate that PS exposure occurs in three stages during the cell death program and that fluorescein-labeled lactadherin permitted the detection of early PS exposure. A similar pattern of PS exposure has been observed in two malignant cell lines with different adherence, suggesting that this pattern of PS exposure is common in adherent cells. Both lactadherin and annexin V could be used in adherent Tca8113 and ACC-2 cell lines when an appropriate harvesting procedure was used. Lactadherin is more sensitive than annexin V for the detection of PS exposure as the physical structure of PS in these blebs and condensed apoptotic cell surface may be more conducive to binding lactadherin than annexin V.

Distribution behavior of ketoprofen enantiomers was examined in a two-phase system containing R, R-di-tartarates or S, S-di-tartarates. The influences of different alkyl chain of R, R-di-tartarates or S, S-di-tartarates, concentrations of R, R-di-tartarate, organic solvent and content of methanol on partition coefficient and separation factor were investigated, respectively. The experimental results show that R, R-di-tartarates studied all form more stable diastereomeric complexes with ketoprofen S-enantiomer than with R-enantiomer. The partition coefficients and enantioselectivity generally increase with the addition of length of alkyl chain of alcohol. The concentration of chiral selector and methanol also have bigger influences on enantioselectivity.