related to the known poecillastrin C (4). The absolute configuration of the β-hydroxyaspartic acid (OHAsp) residue was determined to be D-threo by Marfey's analysis of the hydrolysate. The mode of lactone ring formation of OHAsp residue in 1–3 was determined by selective reduction of the ester linkage followed by acid hydrolysis.
Poecillastrin E(1),F(2)和G(3)从海洋海绵Poecillastra sp。作为细胞毒性成分。通过分析MS和NMR光谱确定它们的平面结构。它们与已知的poecillastrin C(4)密切相关。通过
水解产物的Marfey分析确定β-羟基
天冬氨酸(OHAsp)残基的绝对构型为D-苏式。的OHAsp的内酯环的形成模式中残基1 - 3是由酯键,接着通过酸
水解的选择性还原测定。