The Epimerization Of Sesamin And Asarinin And Their Application On Cellular Aging

Sesamin and asarinin have been shown to have a wide variety of antioxidant activities. Sesame oil lignans undergo transformations, including decomposition, epimerization, and hydrolysis during acid clay refining of the oil. For example, sesamin is epimerized to asarinin. The objective of this paper was to attempt to study the epimerization and separation of sesamin and asarinin and their effect on cellular aging. Sesamin sample containing sesamin of 95% purity for biological applications extracted from unroasted sesame oil by the means of solvent extraction. The yield of asarinin was greatly influenced by operating parameters such as concentration of sesamin, temperature, reaction time and catalyst. We investigate the effect of sesamin and asarinin effect on cellular aging finally.Extraction and purification of sesamin. The methanol extract of unroasted sesame oil was concentrated and purified with the assistance of conventional solvent recrystallization to afford several compounds including two furofuran lignans. Under the optimized conditions, namely, sesame oil: methanol=1: 75(g/mL), crystallization time 45 min, crystallization temperature 65 ℃, the purity of sesamin can be 98.7% by recrystallization analyzed with high performance liquid chromatography(HPLC).The epimerization of sesamin and asarinin. In this part, we have presented that, sesamin can epimerize under acidic conditions. The epimerization can be rationalized as Lewis acid promoted ring fragmentation and leads to the most stable exo-exo furofuran. The epimerization of sesamin increased with the rise of reaction time. Then we found that such reaction was usually occurred in the boiling points in an unexpected way. The reaction equilibrium between sesamin and asarinin may be depend on the hydrogen-bonding nature of the solvents.Separation and purification of asarinin. We first removed the acid with solid phase extraction column. Then we purified the asarinin by medium-pressure preparative liquid chromatography(MPLC). A appropriate method was developed as follows: The mobile phase was methanol–water, the chromatographic flow rate was 20 mL/min, injections volumes were generally 500 u L, the wavelengths of the UV detector were 287 nm. Under this operating conditions, we obtained the purity asarinin.Effect on cellular aging. We compared effect of several antioxidant components served as a cellular model of aging. The results revealed that sesamin and asarinin play significant role in the antioxidant activities; with asarinin, T-AOC content of cells were increased by 292.6%, SOD were increased by 307.3% and MDA decreased by41.3%; with sesamin, the content were 305.2%、339.4% and 41%, respectively. It is suggested that sesamin and asarinin can be delay the cell aging.