Pinnamine

Hjelmgaard, T, Sotofte, 1., and Tanner, D. 2005. Total synthesis of pinnamine and anatoxin-avia a common intermediate. 

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). 

Kigoshi, H., Hayashi, N. and Uemura, D., 2001. Stereoselective synthesis of pinnamine, an alkaloidal marine toxin from... 

Schwarz, S., Kampchen, T, Tilotta, M.C., Gundisch, D, and Seitz, G. 2003. Synthesis and nicotinic binding studies on enan-tiopure pinnamine variants with an 8-azabicyclo[3.2.1]octane moiety. Pharmazie 58, 295-299. 

Takada, N., Iwatsuki, M., Suenaga, K., and Uemura, D. 2000. Pinnamine, an alkaloidal marine toxin, isolated from Pinna... 

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

In a continuation of our work on pinnatoxins, a novel marine alkaloid, pinnamine (10), was isolated from the Okinawan bivalve P. muricata. Pinnamine exhibited acute toxicity against mice, with characteristic toxic symptoms, such as scurrying around and convulsion (LD99 0.5 mg/kg) [17]. The structure of pinnamine (10) was determined to be a unique alkaloid containing a 9-azabicyclo[4.2.1]nonane moiety and a dihydro-y-pyrone ring. The absolute stereostructure was determined by an analysis of the circular dichroism spectrum [18]. 

The structure and toxic symptoms of pinnamine resemble those of anatoxin-a (11) [19,20], a potent postsynaptic depolarizing neurotoxin known as very fast death factor (VFDF), and atropine [21], a representative suppressor of the... 

Recently, an enantioselective synthesis of pinnamine (10) has been achieved (Scheme 3) [22]. The 9-aza-bicyclo[4.2.1]nonane moiety in 10 was constructed by convergence of the /3-keto ester into the silyl enol ether followed by Lewis acid treatment. Synthetic pinnamine was found to correspond uniquely to the natural compound based on a comparison of their spectral data including their CD spectra. 

Cyclic imines, with different chemical structures Pinnatoxins, Pteriatoxins, Pinnamine, ProrocentroHdes, Spiroprorocentrimine, Symbioimines)... 

Pinnamine and oxazinins 1-6 were isolated from the bivalves Pinna muricata (pinnamine) harvested in Japan (Okinawa) and Mytilus galloprovincialis (oxazanins) harvested in the Adriatic Sea. Pinnamine is toxic (LD99 O.Smgkg ) by intraperitoneal injection in mice, and oxazinin-1 is moderately cytotoxic to murine fibrosarcoma WEHI-164 cells, with an IC50 of 16.5 [xgml. ... 

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