Comparison with pheromones

In rabbits, the as yet unidentified maternal signal during lactation has analogous properties in guiding the reliable orientation of suckling, mainly via MOS input (Hudson and Distel, 1986 Schaal et al., unpubl.). Minor fractions may still function as flag contributors, exemplified by the attractiveness of proestrous elephant urine. Male responses show that intact urine is conspicuously more attractive in comparison with the pure insect mammal pheromone (9.) presented in water (Rasmussen et al., 1996). 

Coupled GC-EAD detection analyses of pheromone gland extracts revealed one EAD active compound produced by female Lymentra lucescens and by female L. serva (Lepidoptera Lymantriidae). This compound was identified as 2-methyl-(Z )-7-octadecene by the usual analytical techniques and by comparison with an authentic synthetic compound. 

The extracts contained almost pure pheromone, with only minor amounts of other components. By comparison with synthetic samples, derivatization, and gas chromatography on a chiral cyclodextrin phase, the pheromone was identified as a 95 5 mixture of (5)- and (/ )-enantiomers of dimethyl citrate (cupilure (3), Fig. 4.2). Only the (5)-enantiomer was active (Tichy et al., 2001). Cupilure is probably present in ionized form on the silk (pK 3.5), because solvent extracts were neutral. The ionized carboxyl group may be conjugated to basic amino acids of the silk proteins. This would also explain why the pheromone is not volatile, despite its relatively low molecular weight, and is easily washed from the silk by water, including rain. In the tropical habitat of C. salei this would ensure the presence of cupilure only on freshly laid silk. 

In comparison with volatile pheromones, little is known about chemoreception of contact pheromones. There is some indication that the physical structure, or texture, of the antenna plays a role in the response to contact pheromones, but the processing of these signals has yet to be investigated. Further, ablation experiments suggest that the palpi may be involved in pheromone reception, but electrophysiological and behavioral experimental support to demonstrate this unambiguously is lacking. 

Viridifloric /3-lactone, 143, has been identified as one of the pheromone components of a complex mixture of volatiles released by the pheromone glands of the male Idea leuconoe butterfly during courtship <1996BMC341>. A racemic mixture of both diastereoisomers was synthesized in four steps from the dilithio salt of 3-methylbutyric acid 144 alkylation with ethanal, dehydration of the secondary alcohol with phosphorus pentoxide, dihydroxylation of the C-C double bond with osmium tetraoxide, and finally formation of the /3-lactone by cyclization with sulfonyl chloride. By comparison with the sample isolated from I. leuconoe, the absolute configuration was established to be (2V,3V)-2-hydroxy-2-(l-methylethyl)-3-butanolide 143. 

Bartelt, R. J., Kyhl, J. F Amboum, A.K., Juzwik, J. and Seybold, S. J. (2004). Male-produced aggregation pheromone of Carpophilus sayi, a nitidulid vector of oak wild disease, and pheromonal comparison with Carpophilus lugubris. Agric. For. Entomol., 6, 39—46. 

The structure of the sex pheromone for the Fucus species, fucoserratene (11), was elucidated in 1973.16 The positions and geometries of alkenes were revealed by comparison of the gas chromatographic behavior with those of the isomeric conjugated 1,3,5- and 2,4,6-octatrienes. To date, a series of hydrocarbons and epoxides 1-11 and their stereoisomers have been identified within the pheromone bouquets of more than 100 different species of brown algae.17-23 Identification of these compounds was based on a combination of gas chromatography-mass spectrometry (GC-MS) analysis and by comparison with authentic synthetic compounds. These sex pheromones were all lipophilic, volatile compounds that consisted of C8 or Cn linear or monocyclic hydrocarbons or their epoxides. The monocyclic compounds have a cyclopropane, cyclopentene, or cyclo-heptadiene structure. Interestingly, the relationships between the chemical structures of pheromones and the taxonomical classifications of algae are unclear (Table 1). 

A Comparison of Pheromone, Pheromone and Pyrethrold and Insecticides for Control of the Pink Bollworm In the Imperial Valley, CA." USDA, 1981, Butler G. D. and Barker R. J. Klassen, W. Rldgway, R. L. Inscoe, M., In "Insect Suppression With Controlled Release Pheromone Systems" Kydonleus,... 

The sandfly Lutzomyia longipalpis is the vector of the protozoan parasite Leishmania chagasi, the causative agent of visceral leishmaniasis in South and Central America. Population control of L. longipalpis is therefore of urgent importance to prevent the disease. In 1994, Hamilton and coworkers isolated the male-produced pheromone of L. longipalpis from Jacobina, Brazil, and proposed its structure as 3-methyl-a-himachalene (96, Figure 4.47) with unknown stereochemistry. We first synthesized ( R, 3R, 1 S )-( )-96.81 Enantiomer separation (optical resolution) of a synthetic intermediate enabled us to prepare both the enantiomers of 96, and their bioassay and GC comparisons with the natural pheromone showed the latter to be (lS,3S,lR)-96. 

The results of the hydrogenation of (-)-verbenone (2,6,6-trimethylbicyclo[3.1.1]hept-2-en-4-one) (3) are to be found in Table 3. This compound is a practically important molecule used as the starting material in the synthesis of a sex pheromone [15]. It is a conjugated unsaturated molecule with a hindered rigid bicyclic structure and as such offers a possibility for comparison with the behaviour of the open-chain nonconjugated unsaturated ketone 2. 

Haynes KF, Baker TC (1989) An analysis of anemotactic flight in female moths stimulated by host odour and comparison with the males response to sex pheromone. Physiol Entomol 14 279-289... 

P. A and B induce running and mating behavior in male cockroaches. P. C (previously D ) and D (previously D2) are about 100 times less active. The P. are found mostly in the insects excrements from which they can be isolated (0.2 mg of P. B are obtained from 75 OCX) female insects). The P. only act over short distances, possibly only on contact The biologically most active P. A and P. B occur in P. americana in a ratio of ca. 10 1. The unnatural epoxy epimer of P. A is about 10000-fold less active. The structures were elucidated by synthesis and comparison with the electroanten-nograms (EAG) of natui samples The conformation of the flexible, 10-membered getmacranoids has been studied in detail by NMR spectroscopy and X-ray diffraction. The P. are added to insecticide preparations for the protection of stored products. P. J is the sex pheromone of the Japanese cockroach Periplaneta ja-ponica. ... 

Chiral columns are also employed in pheromone research for the determination of the absolute configuration of stereoisomers. The configuration of 4-methylheptan-3-ol and 4-methylheptan-3-one, sex pheromones of the oak bark beetle, were determined using a fused silica column coated with octakis [6-0-methyl-2,3-di-0-pentyl]-7-cyclodextrin. The elution order of the ketone stereoisomers was determined according to the literature and the natural compound was found to be (S)-methylheptanone. The absolute configuration of the alcohol present in the insects was determined by comparison with authentic standards and was found to be (3R, 4S)-methylheptanol. 

All four possible diastereomers of 2-methyl-5-hydroxyhexanoic acid lactone (628) have been synthesized by Pirkle and Adams (641) and await comparison with natural material to determine which is the pheromone of the carpenter bee. 

Fig. 20.4 Comparison of secreted proteins in pheromone extracted (A) from mental glands of Desmognathus ocoee (which has non-olfactory pheromone delivery) with (B) pheromone extracted from Plethodon shermani (which has olfactory delivery). Lanes 1 and 3 are MW standards. SDS-PAGE (15% Tris-Tricine)... 

A combination of (.Z)-8-dodecenyl acetate and ( )-8-dodecenol was identified from the sex pheromones glands of the carambola fruit borer, Eucosma notanthes Meyrick (Lepidoptera Tortricidae). The ratio of the alcohol to the ester in the extracts was 2 7. GC, GC-MS, chemical deriva-tization, and comparison of retention times with authentic standards were used for identification. ... 

Removal of the auxiliary group from 12 (see p413) to give 13 followed by several steps yields (-)-(65)-tetrahydro-6-undecyl-2//-pyran-2-one (14), a pheromone of the wasp Vespa orientalis. Comparison of the optical rotation of the synthetic product with that of the natural product served to confirm the stereochemistry of the initial reduction to 12. 

Raffioni, S., Miceli, C., Vallesi, A., Chowdhury, S. K., Chait, B. T., Luporini, P., and Bradshaw, R. A., The primary structure of E. raikovi pheromones a comparison of five sequences of pheromones of cells with variable mating interactions, Proc. Natl. Acad. Sci. USA, 89, 2071, 1992. 

A microsomal FAS was implicated in the biosynthesis of methyl-branched fatty acids and methyl-branched hydrocarbon precursors of the German cockroach contact sex pheromone (Juarez et al., 1992 Gu et al., 1993). A microsomal FAS present in the epidermal tissues of the housefly is responsible for methyl-branched fatty acid production (Blomquist et al., 1994). The housefly microsomal and soluble FASs were purified to homogeneity (Gu et al., 1997) and the microsomal FAS was shown to preferentially use methylmalonyl-CoA in comparison to the soluble FAS. GC-MS analyses showed that the methyl-branching positions of the methyl-branched fatty acids of the housefly were in positions consistent with their role as precursors of the methyl-branched hydrocarbons. 

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