Toxins in Nature - Natural Products Chemistry: Sources, Separations, and Structures - page 160

Chromatogram
β-amanitin
α-amanitin
8. 14.
Retention Time/Min
FIGURE 14.6 HPLC separation of the two toxins from Amanita mushroom: α- and
β- amanitin.
in mobile phase solution, was subjected to LC-MS analysis with a conventional octa-
decyl LC separation column. In the tandem mass spectrum, selected ion monitoring
of α- amanitin and β-amanitin at m/z 919-921 and m/z 920-922, respectively, gener-
ates good separation of both amanitin peaks (Figure 14.6).
14.3 MARINE TOXINS FROM ALGAE
Sources of toxin are found in the warm water areas covering the Gulf of Mexico,
from Florida to Texas. These species, which include Karenia brevis, formerly known
as Gymnodinium brevis and Ptychodiscus brevis , are seen as “red tides” caused by
algal blooms, which produce a toxic dinoflagellate. Examples of lipophilic toxins are
shown in Figure 14.7. They are remarkable chemicals, polytoxin (Figure 14.7a) and
brevitoxin (Figure 14.7b).
The isolation of toxins from algae can be achieved as follows: extraction of the
algae using a moderately polar solvent (e.g., acetone, methanol, or acetonitrile)
releases the toxins together with fats and nonpolar lipids. The concentrated solvent
extract is then partitioned between petroleum ether and aqueous 80% methanol to
HISTORICAL NOTE
Red tide toxins, which are produced from algal blooms, were found along
the Pacific Coast of the United States and led to paralytic shellfish poisoning
(PSP). An early description was given over 200 years ago by Captain George
Vancouver exploring the waters of Vancouver Island and Puget Sound in
Washington State. The crewmen became ill after eating mussels. This poi-
soning resulted in death by paralysis, due to collapse of the respiratory sys-
tem. However, the complete structure of the PSP toxin was only determined
30 years ago.