Synthesis of saxitoxins

Saxitoxin (STX), a neurotoxin isolated from Alaskan butter clam, Saxidomus giganteus, inhibits voltage-gated sodium channels by binding to the pore-forming p-loop region. Here we describe stereospecific syntheses of STX and its natural derivatives, (+)-decarbamoylsaxitoxin (dcSTX) and (+)-gonyautoxin3 (GTX3).

Growth Rates and Nitrogen and Carbohydrate Contents of Juvenile Clams, Saxidomus giganteus, Fed Three Species of Algae

Estimates were made of the increase in live and dry weights and in the content of ash, organic matter, carbohydrate (as glucose), and nitrogen when juveniles of the clam Saxidomus giganteus were fed for 21 days at various concentrations of Tetraselmis chui, Isochrysis galbana, and Phaeodactylum tricornutum. The condition index (organic weight as a percent of total dry weight) increased in all the experimental conditions with a mixture of I. galbana and T. chui, yielding a significantly higher index than either species on its own. The relative gain in glucose was greater than the increase in live weight or in nitrogen. The increase in live weight was such that the nigrogen content was approximately constant at 6–7 μgN/mg live weight irrespective of the feeding conditions. The N:glucose ratio decreased with increasing concentrations of I. galbana and P. tricornutum, and at the higher concentrations, where the maximum growth rate of clams occurred, the ratios were lower than in any of the clams fed on T. chui.

Paralytic Shellfish Poison and Melanin Distribution in Fractions of Toxic Butter Clam (Saxidomus giganteus) Siphon

Frozen toxic butter clam (Saxidomus giganteus) siphons were fractionated and each fraction was bioassayed for paralytic shellfish poison (PSP) and chemically analyzed for melanin. Sonication removed over 50% of the melanin from the siphons and this fraction contained nearly 50% of the PSP initially present in the siphons. The data presented further implicate melanin as a PSP binding agent in vivo.