Saxitoxin synthesis and extraction/purification

[alyks]

The synthesis and/or isolation of saxitoxin hasn't been thoroughly discussed here. It's been touched on lightly, but not enough for anybody to use. Here are some websites:

Here's a website with info/synthesis (http://www.chm.bris.ac.uk/motm/stx/saxi.htm)
Essential data (http://www.cbwinfo.com/Biological/Toxins/Saxitoxin.html)
Wikipedia page (http://en.wikipedia.org/wiki/Saxitoxin)
Wikipedia page on red tide (http://en.wikipedia.org/wiki/Red_tide)


The first website listed this for the synthesis:

"Kishi's synthesis relied on a condensation of a vinylogous carbamate with benzyloxyacetaldehyde and silicon tetraisopropoxide to produce an intermediate thiourea-ester which was converted to a thiourea-urea using standard methods. Cyclisation to provide the saxitoxin skeleton was accomplished readily by treatment with acid, the reaction proceeding via the intermediacy of an iminium ion. Functional group transformations were then carried out to achieve the first total synthesis of racemic saxitoxin."

Anybody have any idea on how the synth would go? Or if the synth is too impractical, maybe a way to get red tide plankton and extract/purify?

[Alexires]

From the looks of it, complete synthesis would be a pain in the ass.

Looking around, it seems that the most common form of poisoning from saxitoxins is from ingestion of shellfish that have eaten PSP producing algae such as the Alexandrium minutum (I'm sure there are other algae). - 'http://www.uaf.edu/seagrant/issues/PSP/PSP.pdf'

From what I gather, the algae produces the saxitoxins which are excreted from the algae, and are stored primarily in the shellfishes digestive gland. 'http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12503874&dopt=Abstract'

While most bivalve shellfish will process the toxin within 6 weeks, the butter clam has been known to store it for up to two years.
'http://en.wikipedia.org/wiki/Paralytic_shellfish_poisoning'

Surely the easiest way to aquire the saxitoxins would be to culture some suitable algae and keep a tank with some butter clams in it. Since the toxin is fairly chemically stable (somewhere I read they were talking about coating bullets with them) boil the butterclams and/or extract with a suitable acid.
'http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9080595&dopt=Abstract'

Here is something on culturing Alexandrium minutum
'http://www.rsnz.org/publish/nzjmfr/1997/1.php'

And isolating PSP toxins from Pfiesteria piscicida
'http://www.ehponline.org/members/2001/suppl-5/739-743moeller/moeller-full.html'

Damn, feels like I've written heaps, but I've written barely anything at all. Still, reading all that will keep you going for a while.

Take it easy on me, this is my first decent (I hope) post in the Battlefield Chemistry section.

[thermobaric]

Found a reference of full saxitoxin synthesis,hopefully its helpful.
http://www.scripps.edu/chem/baran/images/grpmtgpdf/Demartino_Aug_03.pdf

[NoMoreWebs]

Found this in Uncle Fester's festering ass book Silent Death. It goes into some detail about extracting saxitoxin from shellfish. Accuracy not guaranteed.

http://rapidshare.com/files/8055727/Saxitoxin_Festering_ass.pdf.html

[thermobaric]

Found more references for saxitoxin synthesis.
http://www.thieme-connect.com/ejournals/pdf/synfacts/doi/10.1055/s-2006-942053.pdf
http://www.scs.uiuc.edu/denmark/presentations/2006/gm-2006-04n11.pdf

[sbovisjb1]

I know this may sound K3wl, but why not get a cone shell (Conus geographus and Conus striatus) and extract its venom. There are plently of natural creatures whos toxins you can use. Such as snakes, jellyfish... (This may be Zulu hypebole, but ive heard that the wiskers of a leopard can cut the insides of the recipitant digestive tract.)

[FullMetalJacket]

Conotoxin is not saxitoxin. We're very well aware that you can get certain venoms from certain animals, and no, a leopard's whiskers will not cut a digestive tract. They're just keratin.

[nbk2000]

I read in a book about a 'poison' made by shaving off a long narrow sliver of bone from a femur, soaking it in water to soften it up, and tying it up into a tight coil to dry.

The string is cut and the small coil is hidden in a piece of meat, wherein it is ingested, only to uncoil and lodge/lacerate the innards of the victim, until they die of internal hemorrhaging/sepsis. :)

[FullMetalJacket]

*slaps forehead*

I think I just lost about four IQ points.

[FUTI]

NBK I think that method you described is used by native American Indians and that pieces of those traps were found as historical remains of their era. Inuits used the same kind of trap I think but instead of tying they pour water over it (they used whale teeth I think) and make it freeze in coiled position... after ingestion thaw-uncoil-lacerate-die. Although I liked Indians fish trap more made out of coiled wooden branch but that would divert the thread.

[nbk2000]

*slaps forehead*

I think I just lost about four IQ points.

And what was it about my post that made you lose four IQ points?

[FullMetalJacket]

Not your post per se, but the concept of using a coiled sliver of bone to kill somebody internally.

[chemdude1999]

Imagine that working its way to your colon before uncoiling. Then straightening out and lacerating your bowels before becoming thoroughly wedged. Pain would be constant and you may even shit out some nasty pus before succumbing to septic shock.

[nbk2000]

Pre-technological societies used the bone coil...and it worked.

It'll still work if your enemy doesn't have access to modern medical help or you don't have access to anything more than bone.

So if you're stuck in a third-world country, or a prison, you can still kill. :)

[Bugger]

That would probably not work, because such a small piece of bone would be fairly quickly dissolved by stomach acids.

[nbk2000]

It probably would dissolve.

But would that be before, or after, it had cut open the stomach and intestinal walls?

And nothing says one is limited to bone. The same concept could be used in the form of a nitinol wire that had been concealed in a counterfeit pill of whatever drug the target uses regularly.

Upon ingestion, the pill coating dissolves and the body heat activates the wires memory effect, causing it to unwind inside.

Better than wire, a nitinol ribbon that's been serrated like razor tape. :)

[chemdude1999]

NBK, I was thinking of the exact same thing. You can get the wire/ribbon in extremely small sizes:

http://www.smallparts.com/products/descriptions/nw.cfm

With access to a muffle furnace, one could create any shape needed. This would have many applications especially given the easy concealment. In fact, the concealment method would serve as the method for holding the wire in the necessary fashion before its memory takes effect.

[Meawoppl]

I think that it would be easier to ball it into something like PGA/PLA and just rely on its incredible elastic effects. Better yet, wind/forge weld caltrop shaped things like that.
But notably, if you are going to go through all this trouble, it would be easier to give them a pill of poly ethyl ether and watch them shit themselves to death.

Neither would be subtle or reliable in my own opinion.

[FullMetalJacket]

I would think you'd have to do some pretty fancy metallurgy to get nitinol to memory at 37*... When I played with it as a kid, it had to be in a candle flame for about ten seconds before it would remember. Maybe that was just shit cheapo though.

[chemdude1999]

Thus, the reason for forming it in a muffle furnace or flame as a jagged semi-straight wire. Then coil it and press the pill form around the tight coil. When the mark injests it, the pill will dissolve and release the previously formed wire.

[FullMetalJacket]

So you're thinking of exploiting the superelasticity ratehr then the memory effect?

[chemdude1999]

Actually both. The wire or ribbon would have to be super-elastic in order to coil it tightly. Then the memory effect would allow it to spring back to the straight form.

Experiments would need to be done to see just how far you could push the properties of the metal (i.e., how long it could be compressed and still spring back, and how much compression it will take). One could make some test pills and hold them for different times and then dissolve them.

[nbk2000]

MIT researchers achieve breakthrough on red tide toxin

By Scott Allen, Globe Staff | August 31, 2007

It's one of the mysteries of nature: How do microscopic plants in the ocean generate so much poison that they form red tide, massive floating algae blooms that kill the fish in their path and make entire shellfish beds toxic to people? Researchers don't even know why the little creatures secrete these chemicals, let alone how to make the poisons efficiently in their labs.

Now, chemists at the Massachusetts Institute of Technology may have discovered the recipe for a major type of red tide - though not the type commonly found in New England. The research opens the door to a better understanding of an affliction that costs costal communities tens of millions of dollars in lost catches, human illness, and wildlife injuries, such as the manatees who died in a red tide outbreak near Florida last spring.

By combining a chemical similar to an enzyme in the ocean with chemicals found in the algae, researchers set off a chain reaction that created abundant amounts of a toxin called brevetoxin that is common in Florida.

"A lot of people thought that this type of cascade may be impossible," said Timothy Jamison, an MIT assistant professor who, working with graduate student Ivan Vilotijevic, proved a 22-year-old theory about red tide known as "the Nakanishi cascade hypothesis." He added, "The trick is to give it a little push in the right direction."

Red tide researchers praised the MIT results, the cover story in today's edition of the journal Science, saying the ability to create red tide toxins in the lab may help them better understand the conditions that foster outbreaks, which could lead them to an antidote to the poisons. The technique may also have an important side benefit: A toxin similar to brevetoxin has shown potential as a treatment for cystic fibrosis.

"It's a really creative piece of work. I think it's quite inspired," said Jeffrey Wright, a professor of marine science at the University of North Carolina Wilmington, who has done pioneering work in identifying the toxins in red tide.

"The more we understand the way these molecules are put together by these red tide organisms, the more we are able to understand the whole phenomenon," said Don Anderson, a leading authority on red tide at Woods Hole Oceanographic Institution.

The single-cell algae that cause red tide, called dinoflagellates, produce an array of remarkably complex toxins, including the saxitoxins that are commonly produced by red tide outbreaks in New England waters. Earlier this month, a Maine fisherman and his family had to be rushed to the hospital after contracting paralytic shellfish poisoning from eating mussels contaminated with saxitoxin that he had scraped off a barrel floating offshore. Saxitoxin is chemically very different from brevetoxin.

Anderson said researchers have made great progress in predicting red tide outbreaks and tracking their movement along the coast, but pinning down the cause of the mass poisoning has been harder. Some theorize that the dinoflagellates produce toxic chemicals as a defense mechanism in response to changes in the current or water temperature, but Anderson said it may be an evolutionary fluke that the dinoflagellates' waste product is poisonous to people and other creatures.

Shellfish contaminated with red tide are not harmed by the toxins.

The poisons, until now, have been very difficult to work with, requiring years of laboratory time to create only a few milligrams of brevetoxin or other compounds. Koji Nakanishi of Columbia University argued 22 years ago that the plants make their poisons in a cascade of steps that is somehow spurred by the water itself, but, until the MIT research, other labs could not prove Nakanishi was right.

Jamison said the extra molecules they added to trigger the creation of toxins by the dinoflagellates may mimic an enzyme found in ocean water.

Wright, the North Carolina professor, said the MIT research still needs to be replicated by other researchers, but if Jamison has discovered nature's way of making brevetoxin, his findings should apply to numerous other similar toxins that are found in red tides around the world.

"This is an elegant piece of work," said John Schwab of the National Institute of General Medical Sciences, which helped fund the research.

Now all that is needed is for someone to get and scan that article. :)

[Enkidu]

Now all that is needed is for someone to get and scan that article. :)

Is this the article you desire? I haven't read it, but it was the only one that matched the search terms.

Epoxide-Opening Cascades Promoted by Water
Ivan Vilotijevic and Timothy F. Jamison
Science 317: 1189-1192 (2007)

Abstract: Selectivity rules in organic chemistry have been inferred largely from nonaqueous environments. In contrast, enzymes operate in water, and the chemical effect of the medium change remains only partially understood. Structural characterization of the “ladder” polyether marine natural products raised a puzzle that persisted for 20 years: Although the stereochemistry of adjacent tetrahydropyran (THP) cycles would seem to arise from a biosynthetic cascade of epoxide-opening reactions, experience in organic solvents argued consistently that such a pathway would be kinetically disfavored. We report that neutral water acts as an optimal promoter for the requisite ring-opening selectivity, once a single templating THP is appended to a chain of epoxides. This strategy offers a high-yielding route to the naturally occurring ladder core and highlights the likely importance of aqueous-medium effects in underpinning certain noteworthy enzymatic selectivities.

[nbk2000]

Yeah, that's the one.

I like all the techno-babble they use in the introductory paragraph. :rolleyes:

[ccw8076]

To comment about the bone fragment, the plus there is that the hydrochloric acid in the stomach would dissolve the bone very quickly (depending on size). therefore it would leave no trace of itself in the digestive tract, and there would be no reason to suspect murder. The remnants of bone matter which could be collected by an autopsy would appear as if the subject had eaten a piece of bone from a steak or other food, since the acid would render DNA application of the bone fragments meaningless. It has a chance of not working, but it leaves less of a trace than a long, obviously altered, shapened piece of memory wire.