Date: Tue, 27 May 1997 13:19:38 -0400 From: "kamikaze" <011114@hillstrath.on.ca> To: cp@opus.hpl.hp.com Message-Id: <aabcdefg2082$foo@default> Subject: Re: digestion in s. purpurea
Recently, I published an article concerning the secretions of S.
purpurea into the water bath they were as follows:
> I have noticed that ants that fall into the trap
> just after I have filled the pitchers with water easily escape, but
> after two days, the little critters are doomed. They can't even
> stuggle for more than 5-10 seconds before curling up and dying. Even
> larger insects are doomed. Adrian Slack says that this is because of
> the effects of a wetting agent, but I doubt this since the insects
> seem to retain their buoyancy and remain afloat in the water even
> after dying. What else could be added to the water, there might be a
> wetting agent, but I suspect there is more, and I have found s.
> purpurea to be quite an efficient insect catcher.
Mr. Jan Scheuler kindly replied by sending the following message:
----------------------------------------------------------------------
This phenomenon has been mentioned on the cp list a while ago. I have
asked the respective subscribers to perform some experiments but they
never replied again. Fortunately, you seem to have done some of the
tests instead. So there is obviously an intrinsic insect stunning
activity found in _S. purpurea_. This is particularly interesting
because usually it is assumed that cps trap their prey by mechanical
means and kill them by suffocation or squeezing (in the aquatic
representatives digestion probably begins when the prey is still
alive, so here it is killed by disintegration).
Now what is this stunning activity? The alkaloid Coniine has been
found in _Sarracenia_. It is toxic for humans but I do not know its
effects on ants. If _S. purpurea_ produces an insect neurotoxin, the
compound (or mixture of compounds) could be active at very low doses,
which in turn could complicate chemical analysis. Nevertheless, some
preliminary analyses could be useful. The first thing I would
investigate is inactivation of the agent. Is the pitcher liquid still
active after it was boiled (for a few minutes, for an hour)? Can the
compound/s be inactivated chemically (add conc. HCl, let act
overnight, neutralize with NaOH, and test for activity; add
NaOH, let act overnight, neutralize with HCl, etc.)? If the compond
survives all these treatments, it can be assumed to be a small and
fairly simple molecule. If it does not, the story is a bit more
complicated.
Now some chromatographic/spectroscopic investigations will be
necessary. Do you have access to a chemical laboratory? If not, I
could ask my boss if he is interested because we do tests for
biologically active natural products in our lab (we investigate the
naphthylisoquinoline alkaloids of _Triphyophyllum_ and its
relatives). For a reliable activity screening we would need a
sensitive test system. Perhaps you could look which insects _S.
purpurea_ is able to knock out. If the range is wide enough, there is
hope that we will find something similar in Europe (it will be too
much trouble to cultivate Canadian ants as test organisms here...).
I can unfortunately not help you much with your cultivation related
problems. But certainly someone on the cp list will.
Kind regards
Jan
----------------------------------------------------------------------
Mr. Adrian Slack said that perhaps S. purpurea has regressed
evolutionarily speaking because it uses water and bacterial decay
instead of enzymes and acids to digest prey. However, if the plant
does indeed have a neurotoxin present, as was suggested by Mr.
Scaheuler, then this would indicate that S. purpurea is atleast as
complex as if not more than the other Sarracenias. Any comments would
be appreciated.
Unfortunately I am not much of a chemist but the HCl and NaOH
(Hydrochloric acid and Sodium Hydroxide) are easy to obtain. This
weekend, I am going to set up a shallow bowl. In one bowl I am going
to place normal distilled water and in the other I am going to place
the water taken out of the S. purpurea pitcher and see if ants how
long two ants survive in each. I will also test what insects are
affected etc.
I will keep you all posted. I hope I didn't bore anyone to death. Any
comments or adivse or info. or speculations on what could be
contained within the S. purpurea digestive bath, would be appreciated.
Happy Cp'ing and thanks Jan for you input,
Adwait Kulkarni
This archive was generated by hypermail 2b30 : Tue Jan 02 2001 - 17:31:03 PST