A Sesterterpene

Retigeranic acid (480), isolated from the Lobaria retigera and related species, is the first example of a lichen sesterterpene. As sufficient information could not be obtained from routine spectral data 205), the structure (and absolute configuration) of (480) was determined by X-ray diffraction of the / -bromoanilide derivative of retigeranic acid 204). A possible biosynthetic route to (480) has also been outlined 205). 

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A Californian sponge of the Halichondriidae family contained a sulfated sesterterpene hydroquinone and five sulfated sesterterpenes. The structures of the halisulfates 1-5 (359-363) were determined by interpretation of spectral data and a structure was proposed for halisulfate 6 (364). The halisulfates are antimicrobial and antiinflammatory [318]. The absolute configuration of halisulfate 3 (361), which was also isolated from Ircinia sp. from the Philippines, has been determined by application of the chiral amide method and by chemical degradation techniques [319]. Halisulfate 7 (365) is a sesterterpene sulfate from a Coscinoderma sp. from Yap, Micronesia [320]. 

Schmitz and co-workers next published a pair of papers that dealt with the isolation and characterization of sesterterpenes from two different sponges. The first of these reports described the structural characterization of phyllofolactones C and D, minor homoscalarane sesterterpenes from the Chinese sponge Phyllospongia foliascens.117 The structure of phyllofolactone-C (54) is shown. The second report detailed the characterization of halisulfate-7 (55), a sesterterpene sulfate from a sponge, Coscinoderma sp.118... 

Problem 29.1 2 Manoalide, a sesterterpene isolated from the Pacific marine sponge Luffariella veriabills by Scheuer and co-workers at the University of Hawai i at Manoa, has anti-inflammatory, analgesic, and antifungal properties. Find the isoprene units in manoalide. 

Luffalactone (95) from the Pacific Luffariella variabilis is a sesterterpene with a labdane type skeleton, related to manoalide (53). Luffalactone showed 52% inhibition of oedema in the mouse ear assay at 50 pg/ear [87],... 

Meroterpenes are fotmd almost exclusively in the genus Dysidea and they involve either a sesquiterpene of the drimane series, a sesterterpene of the scalarane series, with an aromatic moiety that is most often a hydroquinone or quinone, sometimes substituted with a taurine (the melemeleones of Dysidea amra). There are, however, some atypical structures of the dimeric type, containing an aminoquinone. Figures 19.98-19.104 present some examples of terpenes and meroterpenes of dendroceratid sponges some of these have been found, with or without... 

Figure 19.119 (a) Sesterterpenes of the scalarane family isolated from dictyoceratid sponges (b) Further sesterterpenes of the scalarane family... 

Hofheinz, W. and Schdnholzer, P. (1977) Irdnianin a sesterterpene from a sponge, genus Ircinia. Hdv. Chim. Acta, 60,1367-1370. 

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