Ant toxins

Also in the activation of alkynes for nucleophilic attack, gold salts prove to be soft, exceptionally carbophilic Lewis acids, as confirmed by the examples shown in Scheme 3 [10]. According to Utimoto and Fukuda both the addition of water as well as of amines to alkynes are catalyzed by gold(III) salts, in particular by sodium tetrachloroaurate ketones such as 8 and imines such as the ant toxin 10 are obtained as products in excellent yields [10a-e]. In the cyclization reaction giving the 1,4-dioxane 12 developed by Teles et al.,... 

A number of groups have reported syntheses of various ant toxins see, for example, Y. Moriyama et al., Tetrahedron Letters, 1977, 825 R.K. Hill and T. Yuri, Tetrahedron, 1977, 33, 1559). A total synthesis of solenopsin-A is illustrative (K. Fuji, K. Ichikawa and E. Fujita, Chem.pharm. Bull., 1979, 27, 3183) (Scheme 5). 

Blum MS (1984) Poisonous ants and their venoms. In Tu AT (ed) Handbook of natural toxins, vol 2. Insect poisons, allergens, and other invertebrate venoms. Marcel Dekker, New York, p 225... 

Other zoodariid spiders that eat ants or termites possess a well-developed femoral organ, which is used to immobilize or kill prey. Even superficial contact with the organ results in paralysis or death, suggesting that the femoral organ contains a powerful toxin (Jocque and Billen, 1987 Jocque and Dippenaar-Schoeman, 1992). However, H. bradleyi does not have the femoral organs (Jocque and Billen, 1987). 

There is some controversy as to whether the frogs produce the toxins themselves as secondary metabolites or whether they are simply processing their food - ants. Dendrobatid frogs raised in captivity lose their toxicity. In fact, chemical analyses of ants similar (but not identical) to those found in the natural habitat show compounds structurally related to the toxins. 

Although relatively few insect species produce enough toxin to endanger humans, insects cause more fatal poisonings in the U.S. each year than do all other venomous animals combined. Most venomous insects are from the order Hymenoptera, which includes ants, bees, hornets, wasps, and yellow jackets. These insects deliver their toxins by a stinging mechanism. 

Actinidine (92), a plant alkaloid (see section 8), is also a minor component of the defence secretion of the Australian cock-tail ant Iridomyrmex nitidceps (G.W.K. Cavill et al.. Tetrahedron, 1982, 38, 1931), a fact which indicates that ants may obtain toxins (or at least their precursors) from dietary sources. Actinidine has been synthesised (M. Nitta, A. Sekiguchi and H. Koba, Chem.Letters, 1981, 933). Anabaseine (118), a dihydro derivative of anabasine a well known tobacco alkaloid, is present in the poison glands of Aphaenogaster ants for which it also an attractant (J.W. Wheeler et al.. Science, 1981, 211, 1051). Ants from Puerto Rico produce the simple tetrahydropyridine (119) (T.H. Jones, M.S. Blum and... 

Fig. 9.5.6 Direct detection and amplification of the protein toxin Clostridium botulinum toxin A (toxoid). The upper line is an average of three channels with ant -botulinum antibody on the surface.

Other medically important polyketides include the antibiotics doxorubicin (14-hydroxydaunomycin Fig. 5-23), rifamycin (Box 28-and the antifimgal pimaricin, griseofulvin, and amphotericin (Fig. 21-10), the HMG-CoA reductase inhibitor lovastatin, the 2-butanyl-4-methylthreonine of cyclosporin A (Box 9-F), and other immunosuppressants such as rapamycin. Many characteristic plant products, including stilbenes and chalcones (Box 21-E), are polyketides. A variety of different polyketides serve as phytoalexins. Some such as aflatoxin are dangerous toxins. Ants and ladybird beetles make toxic polyamine alkaloids using a polyketide pathway. ... 

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