二甲基巯基丙酸

二甲基巯基丙酸（英語：Dimethylsulfoniopropionate，缩写DMSP）是一种化学式为(CH3)2S+CH2CH2COO−的有机化合物，常以內盐形式存在于海洋浮游植物、海藻以及某些陆生及水生维管植物中。 已隱藏部分未翻譯内容，歡迎參與翻譯。 It functions as an osmolyte as well as several other physiological and environmental roles have also been identified. DMSP was first identified in the marine red alga Polysiphonia fastigiata by Frederick Challenger and Margaret Simpson (later Dr. Whitaker) 已隱藏部分未翻譯内容，歡迎參與翻譯。 In higher plants, DMSP is biosynthesized from S-Methylmethionine. Two intermediates in this conversion are dimethylsulfoniumpropylamine and dimethylsulfoniumpropionaldehyde. In algae, however, the biosynthesis starts with removal of the amino group from Methionine, rather than from S-Methylmethionine. 已隱藏部分未翻譯内容，歡迎參與翻譯。 DMSP is broken down by marine microbes to form two major volatile sulfur products, each with distinct effects on the environment. Its major breakdown product is methanethiol (CH3SH), which is assimilated by bacteria into protein sulfur. Its second volatile breakdown product is dimethyl sulfide (CH3SCH3; DMS). Most DMS in seawater is cleaved from DMSP by the enzyme DMSP-lyase, although many non-marine species of bacteria convert methanethiol to DMS.[來源請求] DMS is also taken up by marine bacteria, but not as rapidly as methanethiol. Although DMS usually consists of less than 25% of the volatile breakdown products of DMSP, the high reactivity of methanethiol makes the steady-state DMS concentrations in seawater approximately 10 times those of methanethiol (~3 nM vs. ~0.3 nM). Curiously, there have never been any published correlations between the concentrations of DMS and methanethiol. This is probably due to the non-linear abiotic and microbial uptake of methanethiol in seawater, and the comparatively low reactivity of DMS. However, a significant portion of DMS in seawater is oxidized to dimethyl sulfoxide (DMSO). Relevant to global climate, DMS is thought to play a role in the Earth's heat budget by decreasing the amount of solar radiation that reaches the Earth's surface. DMSP has also been implicated in influencing the taste and odour characteristics of various products. For example, although DMSP is odourless and tasteless, it is accumulated at high levels in some marine herbivores or filter feeders. Increased growth rates, vigour and stress resistance among animals cultivated on such diets have been reported.[來源請求] DMS, is responsible for repellent, 'off' tastes and odours that develop in some seafood products because of the action of bacterial DMSP-lyase, which cogenerates acrylate. 存档副本. [2013-02-05]. （原始内容存档于2013-03-06）.  DeBose, Jennifer L.; Sean C. Lema; Gabrielle A. Nevitt. Dimethylsulfoniopropionate as a foraging cue for reef fishes (abstract). Science. 2008-03-07, 319 (5868): 1356 [2008-03-21]. PMID 18323445. doi:10.1126/science.1151109. （原始内容存档于2008-12-02）. Vila-Costa, Maria; Rafel Simo; Hyakubun Harada; Josep M. Gasol; Doris Slezak; Ronald P. Kiene. Dimethylsulfoniopropionate uptake by marine phytoplankton (abstract). Science. 2006-10-27, 314 (5799): 652–654 [2008-03-21]. PMID 17068265. doi:10.1126/science.1131043. （原始内容存档于2009-12-11）.  Challenger, Frederick; Margaret Isabel Simpson. Studies on biological methylation. Part XII. A precursor of the dimethyl sulphide evolved by Polysiphonia fastigiata. Dimethyl-2-carboxyethylsulphonium hydroxide and its salts. (pdf). Journal of the Chemical Society (London). 2014-07-14, 1948: 1591–1597 [2014-07-14]. PMID 18101461. doi:10.1039/JR9480001591. （原始内容存档于2018-10-03）.  Scott D. McNeil, Michael L. Nuccio, and Andrew D. Hanson "Betaines and Related Osmoprotectants. Targets for Metabolic Engineering of Stress Resistance" Plant Physiology, August 1999, Vol. 120, pp. 945–949. doi:10.1104/pp.120.4.945 DMS and Climate