Pheromones, alarm

The ant Iridomyrmex pruinosus utilizes 2-heptanone as an alarm pheromone. Figure 17 illustrates the existence of a close correlation of the similarity between 2-heptanone and its analogs in molecular model silhouettes with their alarm activity45. It is noteworthy that the replacement of the methylene group in position 3 of 2-heptanone by the ether linkage yields n-butyl acetate which has the same activity as the natural pheromone. Considerable activity is still retained even when the carbonyl group is replaced by the hydroxyl group. 

Fig. 17. Correlation of the molecular silhouettes of the natural alarm pheromone (2-heptanone) and its analogs with their alarm activity45 (Copyright 1969 by the AAAS)...

The reductive cleavage of the alkylcobalamine is facilitated by light irradiation and can then proceed at a much more positive potential. A demonstration photoelec-trochemical reactor for the Bij-catalyzed photoelectrochemical synthesis of Michael adduct 17, the alarm pheromone of the ant atta texana (Scheme 9) has been constructed where the complete device is driven solely by solar energy . Hopefully, mediated photoelectrochemical reactions of this type will also be realized at chemically modified electrodes. 

Example Optically active acid (16) was needed (p T 107 ) for the synthesis of an ant alarm pheromone. The branch point ( in 16) is also the chiral centre so it is better to avoid disconnections there. The 1,2 C-C disconnection (16a) is ideal as it gives synthon (17), for which we use a malonate ester, and halide (18), available from optically active alcohol (19), a major by-product from fermentation. 

Choose suitable starting materials for syntheses of the inseetioide base for diazinone (43) and the ant alarm pheromone (44). 

Brown G. and Godin J. (1997). Anti-predator responses to conspecific and heterospecific skin extracts by Three-spined Sticklebacks alarm pheromones revisited. Behaviour 134, 1123-1134. 

Graves B.M. and Duvall D. (1988). Evidence of an alarm pheromone from the cloacal secs of prairie rattlesnakes. Southwest Nat 33, 339-346. 

Many different functions of pheromones have been found since Butenandt. Aggregation pheromones attract both sexes to a special location, while sex pheromones are offered by one sex only to attract or arouse the other one. Trail pheromones used by ants mark food trails and alarm pheromones change the state of alertness of conspecifics. These are only some of the functions pheromones can have, and similar different functions can be found in allelochemicals as well. 

W-SA Previously identified alarm pheromone components that (a) change flight activity, (b) increase recruitment, or (c) help localize target Isopentyl acetate 91 (a,b,c),butan-l-ol 92 (b), hexyl acetate 95 (b),butyl acetate 93 (b,c), hexan-l-ol 94 (b,c),octan-l-ol 96 (b),octyl acetate 97 (c),nonan-2-ol 98 (a,b), benzyl acetate 99 (a) [151]... 

W- Antennal response of previously identified alarm pheromone component Heptan-2-one 69 4-methylheptan-3-one 70 [164]... 

Within Hymenoptera, pheromones produced by workers in social colonies are the best studied across many genera, principally in ants [6], with those eliciting trail following most extensively studied. The distinct behavior and the relative ease of the bioassay have resulted in chemical identifications in many species [ 113,114]. Those that have been recently identified are listed in Table 5. In addition, several alarm and recruitment signals have recently been identified. Many of the compounds recently identified in ants have previously been reported as trail or alarm pheromones in other ant species. For example, methyl 4-methylpyrrole-2-carboxylate 64, 3-ethyl-2,5-dimethylpyrazine 65, (9Z)-hexadec-9-enal 66,4-methylheptan-3-ol 67, and methyl 6-methylsalicy-late 68 have been identified as trail pheromone components, and heptan-2-one 69,4-methylheptan-3-one 70, formic acid 71, undecane 61,4-methylheptan-3-ol 67, methyl 6-methylsalicylate 68, and citronellal 72 have been identified as alarm pheromone components [6]. The use of the same chemicals across genera, with some used for very different functions, is an interesting phenomenon. 

P-Pinene (a component of turpentine) An aphid ( H) alarm pheromone... 

All navenones were secreted by Navanax from a specialized gland, the yellow gland , when molested, and also exhibited the capacity to induce an immediate escape reaction to other trail-following Navanax. A series of rigorous bioassays [32] carefully documented the intraspecific alarm pheromone properties of the navenones. 

B. striata, its secondary metabolic pattern, consisting of a series of uncommon polypropionates, is almost identical to that of its prey [36,37], On the contrary, if the mollusc, under maintenance in an aquarium, feeds on Haminoea navicula, it discharges [5] in the form of a yellow secretion two Haminoea metabolites, the haminols (8,9), structurally related to navenone-A (I), which possess alarm pheromone properties [38] for H. navicula. Studies on a third Aglajidae mollusc [39, 40], Philinopsis speciosa, led to the characterization of a 2-alkyl-pyridine, pulo upone (10), as a minor constituent co-occurring with two polypropionates closely related to the metabolites from the pair P. depicta-B. striata. 

Bowers, W.S., Nault, L.R., Webb, R.E. and Dutky, S.R. (1972) Aphid alarm pheromone isolation, idenfication, synthesis. Nature 177, 1121-1122. 

Alarm pheromones, consisting of typical components of bug defensive secretions (e.g., simple aldehydes and esters), have been reported for Leptoglos-sus zonatus [122] and Leptocorisa oratorius [123]. 

The pheromone of Leptocorisa chinensis illustrates the critical importance of the interplay between attractive and inhibitory chemicals [21]. Headspace extracts from males and females were qualitatively similar. From the eight compounds in headspace extracts that elicited strong antennal responses from males, four were discounted as being defensive chemicals or alarm pheromones. The remaining group of four chemicals, consisting of octanol,... 

Anthopleura elegantissima is a small, common sea anemone. It is a bit less than 1 inch across normally. However, it can do some interesting chemistry. If one is wounded, it emits an alarm pheromone as a warning to neighboring members of the same species. When this alarm pheromone hits its receptor, the recipient anemone reacts with a series of quick flexes of its basal tentacles, followed by withdrawing the tentacles into the mouth that then snaps shut. This takes a bit less than 3 seconds overall. 

The alarm pheromone from this sea anemone, anthopleurine, has been isolated and characterized. Like most pheromones, anthopleurine is highly potent. It is an effective alarm pheromone at a concentration of 74 picograms per milliliter (0.00(X)0000(X)74 grams/ml). 

Beale MH, Birkett MA, Bmce TJA, Chamberlain K, Field LM, Huttly AK, Martin JL, Parker R, PhiUips AL, Pickett JA, Prosser IM, Shewry PR, Smart LE, Wadhams LJ, Woodcock CM, Zhang YH (2006) Aphid alarm pheromone produced by transgenic plants affects aphid and parasitoid behavior. Proc Nad Acad Sci USA 103 10509-10513... 

FIGURE 2.1 Hypoxanthine oxide, a fish alarm pheromone. 

FIGURE 7.9 A field experiment to test alarm pheromone in minnows. The minnows were attracted to a feeding table and worms were fed through the tube. When minnows were feeding, macerated minnow skin, containing alarm pheromone, was dropped through the pipe. (From von Frisch, 1941.)... 

FIGURE 7.10 The sequence offish responces to an alarm pheromone. 

European minnow phoxinus Both sexes Alarm pheromone Bradycardia Pfeiffer and Lamour, 1976... 

Pearl dace Semotiltis margarita Both sexes Alarm pheromone ll Plasma cortisol, glucose Rehnberg etal., 1987... 

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