| In this paper, ibuprofen (IBU) enantiomers,2-phenylpropionic acid (PPA) enantiomers and flurbiprofen (FBF) enantiomers were separated by a new chiral separation technique—biphasic recognition chiral extraction. The main contents can be summarized as follows:1 Chiral extraction of ibuprofen (IBU) enantiomers, 2-phenylpropionic acid (PPA) enantiomers and flurbiprofen (FBF) enantiomers. The preferentially chiral recognition ability of extractant (tartrate derivatives andβ-CD derivatives), the influence of the kind organic solvent and concentration of extractant and pH on extraction performance were investigated. The experimental results indicate that biphasic recognition chiral extraction is of strong chiral separation ability. HP-P-CD, HE-β-CD and Me-β-CD have higher recognition ability for one-isomer than that for other-isomer, among which HP-P-CD has the strongest ability. But tartrate derivatives have reversed recognition ability for them. In the extraction system containing HP-β-CD and L-isobutyl tartrate, the extraction effect of IBU is optimum by one stage extraction, and the distribution ratio for R-IBU (kR), S-IBU(ks) and separation factor(α) are 5.85,4.39 and 1.33, respectively; the extraction effect of PPA is optimum by one stage extraction, and the distribution ratio for R-PPA(kR), S-PPA (ks) and separation factor (a) are 1.04,1.75 and 1.69, respectively. In the extraction system containing TM-P-CD and L-isobutyl tartrate, the extraction effect of FBF is optimum by one stage extraction, and the distribution ratio for R-FBF (kR), S-FBF (ks) and separation factor (a) are 11.35,9.19 and 1.24, respectively. Meanwhile, pH and concentration of extractants have great effects on chiral separation ability.2 The inclusion complex formation of ibuprofen withβ-cyclodextrin derivatives (HP-β-CD, HE-β-CD and Me-β-CD) was studied by using phase solubility method and fluorescence spectroscopy. The effects of type and concentration ofβ-CD and pH on inclusion behavior were investigated. Stable inclusion complex in solid state was characterized by DSC. The experimental results indicate:host-guest complexs with 1:1 molar ratio is formed, among which HP-β-CD has the strongest ability to enhance solution and complex with ibuprofen. The solubility of ibuprofen was enhanced with the increase ofβ-cyclodextrin concentration and increase of pH value, but the apparent stability constants and the formation constants decrease with increasing pH.3 The inclusion of 2-phenylpropionic acid (PPA) with P-cyclodextrin derivatives (HP-β-CD, HE-β-CD, Me-β-CD) in aqueous solution was studied by UV spectrophotometry. Effects of type of P-cyclodextrin derivative and presence state of PPA on inclusion. The results show that PPA andβ-cyclodextrin derivatives complex with 1:1 molar ratio is formed, and the order of binding ability of three hosts with PPA is HE-β-CD> HP-β-CD> Me-β-CD; the results also indicate that HP-P-CD is more suitable to complex with molecular state than ironic state.4 The inclusion behavior betweenβ-cyclodextrin derivatives and flurbiprofen was studied by fluorescence spectrophotometry. The effects of type and concentration ofβ-CD derivatives, pH, precentage of alcohol and ironic strength on inclusion behavior were investigated. The results indicate the fluorescence intensity of flurbiprofen increased with the rise of P-CDs concentration, among which HP-P-CD has the most obvious enhancement, namely HP-β-CD has the strongest ability to complex with flurbiprofen. Plot of 1/(F-F0) against 1/[CD] yields a straight line, indicating 1:1 stoichimetric complex formed between P-cyclodextrin derivatives and flurbiprofen. Inclusion behavior enhanced with the ingcrease of ironic strength of solution, whereas followed the opposite tendency with the rise of precentage of alcohol and pH value. |
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