Total Synthesis of the Diglycosidic Tetramic Acid Ancorinoside A
作者:Markus Petermichl、Rainer Schobert
DOI:10.1002/chem.201704379
日期:2017.10.20
Sweet ′n sour: The marine sponge metabolite ancorinoside A was synthesised in 18 steps and 1.6 % yield as the first natural diglycosylated pyrrolidin-2,4-dione. Remarkably, it is comprised of a d-configured aspartic acid, a galacturonic acid and a 3-acyltetramic acid.
The first synthesis of a natural N‐glycosylated 3‐acyltetramic acid is reported. Aurantoside G (1 g), a deep‐red metabolite of the marine sponge Theonella swinhoei, is highly delicate in the pure state. It features a chlorinated dodecapentaenoyl sidechain at an l‐asparagine‐derived tetramic acid, the ring nitrogen atom of which is linked to a β‐configured d‐xylose. The sidechain was built through
In this work, two enzymes responsible for the biogenesis of possible [4 + 2] reaction precursors in the quartromicin biosynthetic pathway were characterized: acetylation of 1 to yield 2 was catalyzed by QmnD3, and subsequent acetic acid elimination of 2 to form double bond product 3 was catalyzed by QmnD4. Site-directed mutagenesis assay of QmnD3 and QmnD4 was investigated, and a general base-catalyzed mechanism for QmnD4 is proposed.
LEY S. V.; WOODWARD P. R., TETRAHEDRON LETT., 28,(1987) N 3, 345-346