title: Rapid purification method for vitamin A-derived aging pigments A2E and iso-A2E using cation exchange resin.
abstract: A2E, known to be involved in the pathogenesis of age-related macular degeneration (AMD), is one of the major compounds that accumulate as fluorescent pigments in retinal pigment epithelial (RPE) cells with age and in some retinal disorders. While the biomimetic synthesis of A2E and its cis-isomer, iso-A2E is as simple as 'one-pot' reaction, the purification of these amphiphillic compounds has been a bottleneck for the mass production of these pathophysiologically important eye pigments. In order to provide a new method of rapid purification of A2E and iso-A2E, we employed a cation exchange resin for the separation of these pigments from crude reaction mixture. The reaction mixture was loaded on a weak acid resin and was eluted with 80% methanol with sodium hydroxide (pH 12), 100% methanol, and 100% methanol with 0.1% trifluoroacetic acid (TFA) in sequence. A2E and isoA2E were eluted only with 100% methanol solution containing TFA. Most of unreacted starting materials and intermediates were removed with 80% methanol containing sodium hydroxide. The new method can be used as a relatively simple and economic way to purify A2E and iso-A2E compared to conventional HPLC technique.
authors: Division of Pharmacognosy, College of Pharmacy, Kyung Hee University, Hoegi-dong, Dongdaemun-gu, Seoul 130-701, South Korea.
authors: Eun Hye
authors: EH
authors: Jee
authors: Department of Optometry, Seoul National University of Science and Technology, Gongneung-gil 138, Seoul 139-743, South Korea.
authors: So Ra
authors: SR
authors: Kim
authors: Division of Pharmacognosy, College of Pharmacy, Kyung Hee University, Hoegi-dong, Dongdaemun-gu, Seoul 130-701, South Korea; Department of Life and Nanopharmaceutical Sciences, College of Pharmacy, Kyung Hee University, Hoegi-dong, Dongdaemun-gu, Seoul 130-701, South Korea. Electronic address: ypjang@khu.ac.kr.
authors: Young Pyo
authors: YP
authors: Jang
mesh_terms: D002411:Cation Exchange Resins / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange / Q000295:instrumentation / Q000379:methods*; D019856:Ethanolamine / Q000737:chemistry; D000432:Methanol; D011726:Pyridinium Compounds / Q000737:chemistry / Q000302:isolation & purification*; D012117:Resins, Synthetic / Q000737:chemistry; D012176:Retinoids / Q000737:chemistry / Q000302:isolation & purification*; D012972:Sodium Hydroxide; D013056:Spectrophotometry, Ultraviolet; D014269:Trifluoroacetic Acid; D014801:Vitamin A / Q000737:chemistry
chemical_list: C112040:A2-E (N-retinylidene-N-retinylethanolamine); D002411:Cation Exchange Resins; D011726:Pyridinium Compounds; D012117:Resins, Synthetic; D012176:Retinoids; D014801:Vitamin A; D012972:Sodium Hydroxide; D019856:Ethanolamine; C024946:Amberlite IRC50; D014269:Trifluoroacetic Acid; D000432:Methanol