del Sol Jiménez María, Garzón Sandra P, Rodríguez Abimael D
Department of Chemistry, University of Puerto Rico, P.O. Box 23346, San Juan, Puerto Rico 00931-3346.
J Nat Prod. 2003 May;66(5):655-61. doi: 10.1021/np030021h.
From a small specimen of the marine sponge Plakortis halichondrioides collected in Puerto Rico we have isolated the known unsaturated ester methyl (2Z,6R,8R,9E)-3,6-epoxy-4,6,8-triethyl-2,4,9-dodecatrienoate (1) along with the known cyclic peroxide plakortide F (2). In addition, the structures of two new polyketide endoperoxides, namely, plakortide O (3) and plakortide P (4), were fully characterized by spectroscopic and chemical methods. The absolute stereochemistry of plakortide O methyl ester (3a) has been determined by analysis of the (R)- and (S)-MTPA esters of the acyclic derivative 5 obtained by hydrogenolysis. Plakortide O (3) and plakortide P (4) exhibited potent cytotoxicity in the NCI human cancer screening program, whereas plakortide O methyl ester, 3a, displayed strong antimalarial activity against Plasmodium falciparum [corrected].
从在波多黎各采集的小型海洋海绵类动物扁海绵（Plakortis halichondrioides）标本中，我们分离出了已知的不饱和酯甲基(2Z,6R,8R,9E)-3,6-环氧-4,6,8-三乙基-2,4,9-十二碳三烯酸酯（1）以及已知的环状过氧化物扁海绵素F（2）。此外，通过光谱和化学方法对两种新的聚酮类内过氧化物，即扁海绵素O（3）和扁海绵素P（4）的结构进行了全面表征。通过对经氢解得到的无环衍生物5的(R)-和(S)-MTPA酯进行分析，确定了扁海绵素O甲酯（3a）的绝对立体化学结构。在NCI人类癌症筛查项目中，扁海绵素O（3）和扁海绵素P（4）表现出强大的细胞毒性，而扁海绵素O甲酯（3a）对恶性疟原虫显示出很强的抗疟活性[已修正]。
