丙二醛(MDA)是生物分子氧化的典型羰基中间体,是脂质过氧化的典型终末产物.这类活性羰基中间体引起组织蛋白的老化与恶化及DNA损伤.牛磺酸在人体内具有非常广泛的生理功能,而γ-氨基丁酸(GABA)是神经系统的一种重要抑制性神经递质,因此二者是两种很重要的非蛋白氨基酸.研究了在生理条件下牛磺酸或GABA是否直接诱捕MDA从而保护组织蛋白不受伤害.将牛磺酸或GABA与MDA在生理条件下温浴48 h,经高效液相、质谱等分析手段分析,发现牛磺酸或GABA与MDA直接反应,通过HPLC分离,都生成两种主产物,一种是没有荧光的紫外吸收峰为274~278 nm的产物,一种是有荧光的产物,这种类似脂褐素(Ex.392~395 nm/Em.456~364 nm)的荧光产物是1,4-二氢吡啶衍生物.牛磺酸或GABA与MDA的反应表明它们在生理条件下具有清除活性羰基的功能,而这种毒性羰基与很多羰基紧张相关的疾病及衰老有关.
Malondialdehyde is a typical product of biomolecule oxidation,and it is also a major product of lipid peroxidation reactions.Tissue deterioration and aging have long been associated with the accumulation of such a compound which induces protein and DNA damage.Taurine(2-aminoethanesulfonic acid) is also involved in a number of crucial physiological processes,and GABA(γ-aminobutyric acid) is a important inhibitory neurotransmitter in nervous system,both of them are two important non-protein amino acids.The purpose of this study is to determine if taurine or GABA can trap MDA directly and thereby prevent advanced lipoxidation end products(ALEs) formation.Direct reaction between MDA and taurine or GABA was researched by using different analytical methods,such as high performance liquid chromatography(HPLC),liquid chromatography/mass spectrometry(LC/MS).The results indicated that taurine or GABA reacted readily with MDA at supraphysiological conditions to form different products.Two nonfluorescent enamines with an absorption peak at 274~278 nm were obtained,and two lipofuscin-like fluorescent(Ex.392~395 nm/Em.456~364 nm) 1,4-dihydropyridine products were derived from reaction of equimolar of taurine+MDA or GABA+MDA using HPLC separation within 48 h.The reaction of taurine or GABA with MDA suggested a novel scavenging reactive carbonyl function of taurine or GABA in pathophysi-ological situations related to carbonyl stress related diseases.