On the Biosynthetic Origin of Methoxymalonyl-Acyl Carrier Protein, the Substrate for Incorporation of “Glycolate” Units into Ansamitocin and Soraphen A
作者:Silke C. Wenzel、Rachel M. Williamson、Christian Grünanger、Jun Xu、Klaus Gerth、Rodolfo A. Martinez、Steven J. Moss、Brian J. Carroll、Stephanie Grond、Clifford J. Unkefer、Rolf Müller、Heinz G. Floss
DOI:10.1021/ja064408t
日期:2006.11.1
the metabolic source of methoxymalonyl-ACP, the substrate for incorporation of "glycolate" units into ansamitocin P-3, soraphen A, and other antibiotics. They point to 1,3-bisphosphoglycerate as the source of the methoxymalonyl moiety and show that its C-1 gives rise to the thioester carbonyl group (and hence C-1 of the "glycolate" unit), and its C-3 becomes the free carboxyl group of methoxymalonyl-ACP
用同位素标记的前体喂养实验排除了羟基丙酮酸和 TCA 循环中间体作为甲氧基丙二酰-ACP 的代谢来源,这是将“乙醇酸”单位掺入安丝菌素 P-3、soraphen A 和其他抗生素的底物。他们指出 1,3-二磷酸甘油酸酯是甲氧基丙二酰部分的来源,并表明其 C-1 产生硫酯羰基(因此“乙醇酸酯”单元的 C-1),其 C-3 成为甲氧基丙二酰-ACP 的游离羧基,在 I 型模块化聚酮化合物合酶 (PKS) 的后续克莱森缩合中丢失。d-[1,2-(13)C(2)]Glycerate 也被特异性地掺入到 soraphen A 的“乙醇酸”单元中,但不是安丝菌素 P-3,表明生产生物体激活甘油酸的能力存在差异。提出了从 1,3-二磷酸甘油酸到甲氧基丙二酰-ACP 的生物合成途径。作为这项工作的一部分,开发了 R-和 S-[1,2-(13)C(2)] 甘油的两种新合成方法。
Chemo-Enzymatic Synthesis of Thymidine13C-Labelled in the 2′-Deoxyribose Moiety
作者:Niels Ouwerkerk、Jacques H. van Boom、Johan Lugtenburg、Jan Raap
A synthesis of [3′,4′-13C2]thymidine (1) is described in which [13C2]acetic acid (2) is converted into the nucleoside in twelve steps with 9% overall yield. D-2-Deoxyribose-5-phosphate aldolase (DERA, EC 4.1.2.4) and triosephosphate isomerase (TPI, EC 5.3.1.1) are used for the stereocontrolled formation of D-[3,4-13C2]-2-deoxyribose-5-phosphate (8) from [2,3-13C2]dihydroxyacetone monophosphate (DHAP