Feeding experiments of C-13-labeled compounds to dinoflagellates have unveiled existence of methionine cascade pathway from methionine to sulfonium compounds such as 3-dimethylsulfoniopropionate, gonyauline and gonyol in a dinoflagellate. (C) 1997 Elsevier Science Ltd.
l-methionine related l-amino acids by acylase cleavage of their corresponding
作者:Andreas S. Bommarius、Karlheinz Drauz、Kurt Günther、Günter Knaup、Michael Schwarm
DOI:10.1016/s0957-4166(97)00400-x
日期:1997.10
Acylase I from Aspergillus oryzae is an even more useful enzyme than suggested so far. Besides standard amino acids such as L-Met, L-VaI and L-Phe, a number of additional sulfur-and selenium-containing amino acids can be obtained at useful reaction rates and in very high enantiomeric purity by kinetic resolution of the respective N-acety-DL-amino acids. (C) 1997 Elsevier Science Ltd.
Aldehyde-catalysed carboxylate exchange in α-amino acids with isotopically labelled CO2
作者:Odey Bsharat、Michael G. J. Doyle、Maxime Munch、Braeden A. Mair、Christopher J. C. Cooze、Volker Derdau、Armin Bauer、Duanyang Kong、Benjamin H. Rotstein、Rylan J. Lundgren
DOI:10.1038/s41557-022-01074-0
日期:2022.12
The isotopiclabelling of small molecules is integral to drug development and for understanding biochemical processes. The preparation of carbon-labelled α-amino acids remains difficult and time consuming, with established methods involving label incorporation at an early stage of synthesis. This explains the high cost and scarcity of C-labelled products and presents a major challenge in 11C applications
小分子的同位素标记对于药物开发和理解生化过程至关重要。碳标记 α-氨基酸的制备仍然困难且耗时,现有方法涉及在合成的早期阶段掺入标记。这解释了 C 标记产品的高成本和稀缺性,并在11 C 应用中提出了重大挑战( 11 C t 1/2 = 20 分钟)。在这里,我们报道醛催化天然α-氨基酸与*CO 2 (* = 14, 13, 11) 的同位素羧酸酯交换。蛋白质α-氨基酸和许多含有不同官能团的非天然变体经过标记。该反应可能通过亚胺-羧酸盐中间体捕获*CO 2进行,生成易于单脱羧的亚氨基丙二酸盐。回火催化剂的亲电性是防止不可逆醛消耗的关键。亚胺羧酸盐中间体的预生成允许在[ 11 C]CO 2存在的情况下对α-氨基酸进行快速和后期的11 C放射性标记。