title: Elution profile of di-peptides on a sulfonated ethylstyrene-divinylbenzene copolymer resin column by high-performance liquid chromatography.
abstract: This study investigates the characteristics of a partially sulfonated ethylstyrene-divinylbenzene copolymer for the separation of di-peptides by high-performance liquid chromatography. Di-peptides (VE, VA, VH, VK, and VR) with different isoelectric points (pI, 4.0 to 9.7) and log P values (-1.63 to -0.72) were used to optimize the separation conditions of the columns packed with sulfonated copolymer resin. The retention factor (k) of the di-peptides on the column with a 0.81 wt% sulfo group content decreased with increasing concentrations of phosphate salts (2.5 - 20 mmol L(-1)) in the mobile phase. The complete separation of the five di-peptides was obtained with a gradient of 10% methanol containing 5 mmol L(-1) NaH2PO4 (pH 4.8) to 50% methanol containing 5 mmol L(-1) Na2HPO4 (pH 8.9) for 60 min at 0.5 mL min(-1) at 50°C. Under the optimal conditions, a good relationship between the k and pI values of the di-peptides, with the exception of VE (pI 4.0), was observed, suggesting that the retention of the di-peptides on the column packed with sulfonated copolymer resin was dependent on the pI value, when it was greater than 5. The log P value also influenced the separation characteristics of the column; peptides possessing the same pI value (6.4 for GH, VH, IH, and FH) showed a higher retention on the column with increasing log P values. In conclusion, the prototype sulfonated ethylstyrene-divinylbenzene copolymer column was applicable for the separation of basic di-peptides, and the separation depended on the pI and hydrophobicity of the di-peptides.
authors: Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School of Kyushu University.
authors: Jian
authors: J
authors: Guo
authors: Tomomi
authors: T
authors: Saiki
authors: Kumrungsee
authors: K
authors: Thanutchaporn
authors: Wanying
authors: W
authors: Liu
authors: Akihiro
authors: A
authors: Shimura
authors: Toshiro
authors: T
authors: Matsui
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004151:Dipeptides / Q000302:isolation & purification*; D057927:Hydrophobic and Hydrophilic Interactions; D007474:Ion Exchange; D011108:Polymers / Q000737:chemistry*; D012117:Resins, Synthetic / Q000737:chemistry*; D020058:Styrene / Q000737:chemistry*; D013451:Sulfonic Acids / Q000737:chemistry*; D014753:Vinyl Compounds / Q000737:chemistry*
chemical_list: D004151:Dipeptides; D011108:Polymers; D012117:Resins, Synthetic; D013451:Sulfonic Acids; D014753:Vinyl Compounds; D020058:Styrene; C004985:divinyl benzene