Disidea pallescens

The structures of several new sesquiterpenoids isolated from a marine sponge (Disidea pallescens) have been assigned on the basis of spectral characteristics and... 

UV, IR, PMR, Mass Spec organism Disidea pallescens (Porifera) reference 85... 

Five more furanosesquiterpenes have recently been isolated from acetone extracts of the sponge Disidea pallescens, all of which, on a preliminary spectral examination, contain a 2,3-disubstituted furan ring 61). For the major components pallescensin-G and -F, the isomeric structures (43) and (44) have been proposed, respectively, on spectral grounds and biogenetic considerations 46). The spectral arguments are briefly summarized below. 

A cyclic sesterterpene linked to a hydroxyhydroquinone ring has recently been isolated as the sodium calcium salt of the disulphate, from Disidea pallescens 44). For the free phenol, disidein, formula (140) can be proposed as the most probable structure, mainly on spectral and bio-genetic grounds. 

Even more significant is the co-occurrence in Disidea pallescens of the pentaprenyl-/7-benzoquinone (115, n = 5) 44). 

Cimino, G., S. De Stefano, and L. Minale Occurrence of 4-hydroxyphenylpyruvic acid oxime in the marine sponge Hymeniacidon sanguinea. Experientia 31, 756 (1975). Cimino, G., S. De Stefano, A. Guerriero, and L. Minale Furanosesquiterpenoids in sponges-I Pallescensin-1, -2, and -3 from Disidea pallescens. Tetrahedron Letters 1975, 1417. 

Cimino, G., S. De Stefano, and L. Minale /1 Chromazonarol, a Chroman-Sesquiterpenoid from the sponge Disidea pallescens. Experientia 31, 1117 (1975). 

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