摘要:

AbstractThe interaction of amino acids with ethoxylated stearic acid nonionic surfactants was studied by charge‐transfer reversed‐phase thin‐layer chromatography and the relative strength of interaction was calculated. In the majority of cases the surfactant has a negligible effect on the hydrophobicity of amino acids. Only the binding of Asn, Cys, Gln, Leu, Lys, Met, Nle, Phe, Ser, Trp and Tyr to the surfactants was observed, however, the strength of interaction was fairly low. Stepwise regression analysis proved that the electronic parameters of the amino acids have the highest impact on the strength of interaction. This finding supports the hypothesis that the binding of ethoxylated stearic acid nonionic surfactants to proteins involves more than one amino acid residues and that the hydrophilic forces have a considerable impact on the intera

ISSN:0269-3879    

DOI:10.1002/bmc.1130080112

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

Abstract(−)‐Isoproterenol (ISO), used as bronchodilator, and (−)‐(R)‐1‐(3,4‐dihydroxyphenyl)‐2‐ [(3,4‐dimethoxyphenethyl)amino]ethanol (T‐0509), a new cardiotonic agent, were determined in rat plasma (only 25 μL) using a fully automated catecholamine (CA) analyser that includes in‐line pre‐extraction of CAs, coupled with an HPLC–ethylenediamine condensation reaction and a peroxyoxalate chemiluminescence detection system (HPLC–ED–PO‐CL). The chromatographic conditions were: precolumn, SERUMOUT‐CEX; buffer for delivering CAs in the precolumn, 10 mMpotassium phosphate buffer (pH 7.5)/ethanol (92 + 8, v/v) (1 mL/min); precolumn clean‐up solution, 4% phosphoric acid/acetonitrile (50 + 50, v/v) (1 mL/min); analytical column, TSKgel ODS‐80Ts, 250 × 4.6 mm i.d.; eluent, 75 mMpotassium acetate buffer (pH 3.2)/50 mMpotassium phosphate buffer (pH 3.2)/acetonitrile (83.6 + 4.4 + 12, v/v/v for ISO and 76 + 4 + 20 v/v/v for T‐0509) (1 mL/min); fluorogenic reagent solution, 105 mMED and 175 mMimidazole in acetonitrile/ethanol (90 + 10, v/v) (0.25 mL/min); chemiluminogenic reaction solution, 0.25 mMTDPO, 150 mMhydrogen peroxide and 110 mMTFA in dioxane/ethyl acetate (50 + 50, v/v) (1.4 mL/min). Colterol, (±)‐1‐(3,4‐dihydroxyphenyl)‐2‐[(1,1‐dimethyl)ethylamino]ethanol, (±)‐N‐t‐butylnorepinephrine was used as an internal standard (IS) for ISO, and (±)‐1‐(3,4‐dihydroxyphenyl)‐2‐ [(3,4,5‐trimethoxyphenethyl)amino]ethanol, (±)‐(3,4,5‐trimethoxyphenethylaminomethyl)‐3,4‐dihydroxybenzylalcohol (T‐1583) for T‐0509.

ISSN:0269-3879    

DOI:10.1002/bmc.1130080113

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

ISSN:0269-3879    

DOI:10.1002/bmc.1130080114

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

ISSN:0269-3879    

DOI:10.1002/bmc.1130080101

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY