Pinna muricata

Three novel related marine alkaloids, halichlorine (1148) from the sponge Halichondria okadai (1177, 1178) and pinnaic acid (1149) and tauropinnaic acid (1150) from the bivalve Pinna muricata (1179), have been the objects of much synthetic interest in view of their pronounced biological activity (inhibition of the vascular cell adhesion molecule-1) (1180). Synthesis of these alkaloids led to both revision and confirmation of the original structures (1181,1182). The syntheses of the previously known chlorine-containing cylindricines have been reviewed (1183). 

Chou T, Kuramoto M, Otani Y, Shikano M, Yazawa K, Uemura D (1996) Pinnaic Acid and Tauropinnaic Acid Two Novel Fatty Acids Composing a 6-Azaspiro[4.5]decane Unit from the Okinawan Bivalve Pinna muricata. Tetrahedron Lett 37 3871... 

Chou, T., Haino, T., Kuramoto, M., and Uemura, D., Isolation and structure of pinnatoxin D, a new shellfish poison from the Okinawan bivalve Pinna muricata, Tetrahedron Lett., 37, 4027, 1996. 

A seventh novel alkaloidal toxin, pinnamine, was isolated and pnrified from the viscera of the Okinawan bivalve Pinna muricata (Takada et al. 2000). Its gross stmctnre, clarified by a detailed analysis of NMR and CD spectra, includes a 9-azabicyclo[4.2.1]nonane pharmacophoric element (Fig. 18.6A). Further synthetic studies have not only confirmed the absolute stereochemistiy of the molecule, but have also allowed stereocontrolled access to a non-natural congener, 5-epi-pinnamine, of the natural product (Kigoshi et al. 2001 Hjelmgaard et al. 2005). 

Uemura, D., Chou, T, Haino, T, Nagatsu, A., Fukuzawa, S., Zheng, S.Z. and Chen, H., 1995. Pinnatoxin A atoxic amphoteric macrocycle from the Okinawan bivalve Pinna muricata. JAm Chem Soc 117, 1155-1156. 

Chou, T, Kamo, O., and Uemura, D. Relative stereochemistry of pinnatoxin A, a potent shellfish poison from Pinna muricata. Tet. Lett., 37, 4023 026, 1996b. 

Takada, N. et al., Pinnatoxins B and C, the most toxic components in the pinnatoxin series from the Okinawan bivalve Pinna muricata. Tetrahedron Lett. 42(20), 3491-3494, 2001. 

Pinnatoxins A and D have been isolated from the Pen Shell, Pinna muricata, from Japan [31-33], Pinnatoxins B and C, which are stereoisomers, were isolated as a 1 1 mixture from the same source... 

Pinnatoxins. Mussel toxins from the genus Pinna Pinna attenuata, P. pectinata). These mussels are precious food in the coastal regions of Japan and China and contain varying amounts of P. Poisonings are common but only rarely lethal. The P. are spirocyclic acetals, e.g., P. A C41H61NO, Mr 711,94, [a]n +2.5° (CH,OH), LD99 (mouse i.p.) 180 pg/kg isolated from Pinna muricata see also PSP. 

Pinnatoxin A (197), isolated from the shellfish Pinna muricata, is an important toxic principle in Pinna shellfish intoxieation outbreaks in China and Japan. Its unique molecular architecture, accompanied by its pronounced biological activity as a Ca " -channel activator, makes pinnatoxin an intriguing synthetic target. A MBH analogous reaction, namely, Ni(ii)/Cr(ii)-mediated coupling between aldehyde 198 and 2-iodoacrylic add derivative 199 to give MBH adduct 200 in 88% yield, was utilized as a key step in the total synthesis of (-)-pinnatoxin A (Scheme 5.37). As part of the synthetic strategy, a biomimetic intramolecular Diels-Alder reaction was developed to construct the macrocyclic structure of (-)-pinnatoxin A. 

Pinnamine, an Alkaloidal Marine Toxin from Pinna muricata. 163... 

Uemura D, Chou T, Haino T, Nagatsu A, Fukuzawa S, Zheng SZ, Chen H (1995) Pinnatoxin A a toxic amphoteric macrocycle from the Okinawan bivalve Pinna muricata. J Am Chem Soc 117 1155... 

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