Varoglu M, Peters B M, Crews P
Department of Chemistry and Biochemistry, University of California, Santa Cruz 95064.
J Nat Prod. 1995 Jan;58(1):27-36. doi: 10.1021/np50115a003.
A morphologically distinct Fijian sponge, Plakortis sp., has yielded two new peroxides, plakortolide E [5] and plakoric acid [12]. After standing for approximately one year, plakortolide E rearranged to plakortolide ether [10]. The structures of plakortolide E [5] and plakortolide ether [10] were established from 2D nmr data and by analogy to a known compound, plakortolide [3]. The stereochemistry of the bicyclic ring substituents of 5 was established using nOe and NOESY nmr data along with comparisons to 3. The absolute stereochemistry at the three chiral sites of 5 was assigned by preparing acyclic compounds 6-9, and both 8 and 9 were investigated using the modified Mosher's method. This represents the first absolute stereochemistry determination for a sponge-derived polyketide peroxide. The characterization of plakoric acid [12] was based on spectral analogies to known polyketides such as plakortin. Plakortolide E [5] exhibited selective potency against the melanoma and breast tumor cell lines in the in vitro 60-cell line panel of the National Cancer Institute.
一种形态独特的斐济海绵，即扁海绵属（Plakortis sp.），产生了两种新的过氧化物，即扁海绵醇内酯E [5]和扁海绵酸[12]。放置约一年后，扁海绵醇内酯E重排为扁海绵醇内酯醚[10]。扁海绵醇内酯E [5]和扁海绵醇内酯醚[10]的结构通过二维核磁共振数据并与已知化合物扁海绵醇内酯[3]类比得以确定。利用核Overhauser效应（nOe）和核Overhauser效应相关光谱（NOESY）核磁共振数据以及与3进行比较，确定了5的双环环取代基的立体化学。通过制备无环化合物6 - 9确定了5的三个手性位点的绝对立体化学，并且使用改良的莫舍尔方法对8和9进行了研究。这是首次对源自海绵的聚酮过氧化物进行绝对立体化学测定。扁海绵酸[12]的表征基于与已知聚酮化合物如扁海绵素的光谱类比。在国立癌症研究所的体外60细胞系面板中，扁海绵醇内酯E [5]对黑色素瘤和乳腺癌细胞系表现出选择性效力。
