The Asymmetric Synthesis Of S-Adenosyl-L-Methionine

S-Adenosyl-methionine (SAM, AdoMeto or SAMe) is an important physiologically active substance in a variety of biochemical reactions, and shows extensive and diversified role in the treatment of arthritis, depression, liver dysfunction, and so on. Though the worldwide demands for it are very large, SAM mainly produced through the fermentation, with low yield, thus its price quite high.S-adenosyl-L-methionine is a chiral substance, only the (S, S) -SAM, also (-) -SAM has physiological activities. This study focuses on (S, S) -SAM chemical asymmetric synthesis. The main results are as follows:(1)The asymmetric synthesis of S-adenosyl-L-methionine. This section is based on adenosine and L-methionine for raw materials, through 5-step reaction to get the S-adenosylmethionine.(2)In the preparation of L- homocysteine sodium salts, taking into account the long reacting time and the low yield, we appropriately improve its reacting conditions by reducing the reaction time and increase the efficiency of the reaction; In the formation of S-adenosyl-L-homocysteine, the literature caused the product a certain loss, in order to improve its yield, we removed the use of KI and the activated carbon, thereby increasing the yield. In addition, in asymmetric methylation process, we used boron trifluoride dietheyl etherate as the raw material instead of boron trifluoride gas. The reaction was easy to control and the yield was satisfying. Finally, in the methylation reaction of S-adenosyl methionine, anisole was used in the extraction process of trifluoroacetic acid, then distilled to recover the trifluoroacetic acid.(3)The preparation and confirmation of adenosylmethionine 1, 4-butanedisulphonic acid. Extraction of the S-adenosylmethionine with methanol, the crystal was filtered, dissolved in water and then washed with dichloromethane, Then passed through the cation exchange resin column, eluted with 1,4- butanedisulphonic acid. Then the water solution received was rotary evaporated to receive solid products. The products were confirmed through HPLC,UV,IR,¹HNMR,¹³CNMR,MS etc.