120 Improved synthesis of three methyl-branched pheromone components produced by the female lichen moth.
Female moths of
Lyclene dharma dharma (Arctiidae, Lithosiinae) produce a novel sex pheromone composed of three methyl-branched ketones: 6-methyl-2-octadecanone (I), 14-methyl-2-octadecanone (II), and 6,14-dimethyl-2-octadecanone (III). Their structures were confirmed by syntheses accomplished by a different route for each component. In order to obtain a sufficient amount of the synthetic pheromone, we developed new routes via methyl-branched 1-alkenes: 6-methyl-1-octadecene (1), 14-methyl-1-octadecene (2), and 6,14-dimethyl-1-octadecene (3). Compound 1 was synthesized by coupling between a C
10-chain bromide and a 3-methyl-branched C
8 unit (A) prepared from 3-methyl-1,5-pentanediol, 2, by coupling between a C
11-chain bromide and a 3-methyl-branched C
7 unit (B) prepared from 2-hexanone, and 3, by connecting A and B, using propargyl alcohol as a C
3 linchpin. The use of 3-chloro-1-propanol and tert-butyl acetoacetate as the linchpin was also examined to connect the two synthetic blocks in the synthesis of 3. Components I-III were obtained by Wacker oxidation of the corresponding 1-alkens 1-3 in good yields.
121 Positions and stereochemistry of methyl branches in the novel sex pheromone components produced by a lichen moth, Lyclene dharma dharma.
Female moths of
Lyclene dharma dharma (Arctiidae, Lithosiinae) produce three sex pheromone components (I-III), for which we assigned the following novel chemical structures; 6-methyl-2-octadecanone (1) for I, 14-methyl-2-octadecanone (2) for II, and 6,14-dimethyl-2-octadecanone (3) for III. In the Iriomote Islands where the insects were collected, a lure including racemic 1 and 2 attracted the male moths without mixing 3. In this study for further confirmation of the plane structures, the positional isomers with a methyl branch at the 4-, 5-, 7-, 13-, or 15-position (4-8, respectively) were synthesized. The GC-MS analyses revealed that natural components I and II were best fitted with those of 1 and 2, respectively, among the methyl-2-octadecanones examined, indicating the usefulness of this analytical instrument and authentic standards for the determination of the positions of methyl branches. In field trapping tests, 4-8 could not substitute for 1 or 2, nor did these compounds inhibit the active binary lure of 1 and 2, indicating that the males strictly recognized the 2-ketones with a methyl branch at the 6- or 14-positions. Next, the absolute configurations of I and II were determined by HPLC with a normal-phased chiral column (Chiralpak AD-H), which could separate the enantiomers of both 1 and 2. The chiral HPLC analysis of a crude pheromone extract indicated that the females exclusively produced (
S)-1 and (
S)-2. Furthermore, a field evaluation of each enantiomer revealed that (
S)-1 and (
S)-2 were bioactive but (
R)-1 and (
R)-2 were not.
122 Female sex pheromone of Glossosphecia romanovi (Lepidoptera: Sesiidae): identification and field attraction.
In field screening tests of synthetic pheromone candidates for Japanese sesiid species, a mixture of (3
Z,13
Z)-octadecadien-1-ol and (3
Z,13
Z)-octadecadienyl acetate successfully attracted male moths of
Glossosphecia romanovi, a harmful pest of vine trees. The GC-EAD and GC-MS analyses of the pheromone gland extract revealed that the female moths produced the alcohol and acetate in a ratio of about 20:1, in addition to three other minor structure-related components.
123 Female sex pheromone of a lichen moth Eilema japonica (Arctiidae, Lithosiinae): components and control of production.
Seven candidates for components of the female sex pheromone of
Eilema japonica (Arctiidae, Lithosiinae) were detected in an extract of pheromone glands with a gas chromatograph-electroantennographic detector. The compounds were identified as (
Z,Z)-6,9-icosadiene (D20), (
Z,Z)-6,9-henicosadiene (D21), (
Z,Z,Z)-3,6,9-henicosatriene (T21), (
Z,Z)-6,9-docosadiene (D22), (
Z,Z,Z)-3,6,9-docosatriene (T22), (
Z,Z)-6,9-tricosadiene (D23), and (
Z,Z,Z)-3,6,9-tricosatriene (T23). Assays using synthetic lures in a wind tunnel showed that D21 (proportion, 0.39), T21 (0.08), D22 (0.27), and T22 (0.26) are important for evoking full behavioral responses from the males. Titers of the pheromone components did not show clear temporal fluctuations. Moreover, decapitation of the female moth had no effect on the titers of pheromone components in the pheromone gland, suggesting that cephalic endocrine factors such as pheromone biosynthesis activating neuropeptide (PBAN) are not involved in the control of pheromone biosynthesis in this species.
124 Novel components of the sex pheromones produced by emerald moths: Identification, synthesis, and field evaluation.
The subfamily Geometrinae (Lepidoptera: Geometridae) includes many species called emerald moths. Based on our recent finding of novel polyenyl compounds, including a double bond at the 12-position from two geometrine species,
Hemithea tritonaria and
Thalassodes immissariaintaminata, (6
Z,9
Z,12
Z)-6,9,12-trienes and (3
Z,6
Z,9
Z,12
Z)-3,6,9,12-tetraenes with a C
17-C
20 straight chain were synthesized and analyzed by GC-MS. The 6,9,12-trienes, which were prepared by a double Wittig reaction between two alkanals and an ylide derived from (
Z)-1,6-diiodo-3-hexene, characteristically produced fragment ions at
m/z 79, 150, and M-98. The 3,6,9,12-tetraenes, which were prepared by a coupling between (
Z)-3-alkenal and an ylide derived from (3
Z,6
Z)-1-iodo-3,6-nonadiene, showed fragment ions at
m/z 79, 148, and M-96. These diagnostic ions were useful to distinguish these compounds from other known polyenyl pheromones, such as 4,6,9- and 6,9,11-trienes and 1,3,6,9-tetraenes. With reference to the GC-MS data, pheromone extracts of other species in Geometrinae inhabiting the Iriomote Islands were analyzed, and the 6,9,12-trienes were identified in the pheromone gland extracts of
Pamphlebia rubrolimbraria rubrolimbraria and
Maxates versicauda microptera. Furthermore, a field evaluation of the synthetic polyenes in a mixed forest of Tokyo revealed the following new male attractants for emerald moths:
Idiochlora ussuriaria by a C
17 6,9,12-triene and
Jodis lactearia by a C
20 3,6,9,12-tetraene, indicating the characteristic chemical structures of Geometrinae pheromones. On the other hand, through reexamination of the pheromone extract of
H. tritonaria, (3
E,6
E)-α-farnesene was identified as an electrophysiologically active component in addition to the C
17 6,9,12-triene. The binary mixture attracted more males than the single component lure baited with the triene in the Iriomote Islands.
125 Sex pheromone components and control of the citrus pock caterpillar, Prays endocarpa, found in the Mekong Delta of Vietnam.
The citrus pock caterpillar,
Prays endocarpa (Yponomeutidae; Praydinae), is a pest of pomelo (
Citrus grandis L.) in Vietnam. Gas chromatography-mass spectrometry analyses of pheromone gland extracts from female moths identified three monoenyl compounds, (
Z)-7-tetradecenal (Z7-14:Ald), (
Z)-7-tetradecenyl acetate (tentatively identified, Z7-14:OAc), and (
Z)-7-tetradecen-1-ol (Z7-14:OH), in a ratio of about 10:3:10. In the field, traps baited with synthetic Z7-14:Ald (0.5 mg) caught male
P. endocarpa. The other two compounds, either alone or when added to Z7-14:Ald, did not elicit increases in trap catch (relative to the appropriate treatment). Synthetic Z7-14:Ald was used to monitor and control this species in pomelo orchards in Vinh Long Province. Monitoring revealed that adults were present throughout the year with discernible peaks in December, March, and April. A mass-trapping trial, using 20 traps in a 0.1 ha pomelo orchard, effectively suppressed fruit damage to levels similar to that achieved by an insecticide (Karate 2.5EC). Mating disruption trials, using polyethylene-tube dispensers, each filled with 80 mg of Z7-14:Ald at a rate of 200 or 400 dispensers/ha, also controlled damage by this pest to levels below that achieved by an insecticide treatment. This work demonstrates the potential for pheromone-based control of this pest in Vietnam.
126 Biosynthetic pathways of the sex pheromone components and substrate selectivity of the oxidation enzymes working in pheromone glands of the fall webworm, Hyphantria cunea.
The fall webworm,
Hyphantria cunea Drury (Lepidoptera: Arctiidae), is a harmful polyphagous defoliator. Female moths produce the following four pheromone components in a ratio of about 5:4:10:2; (9
Z,12
Z)-9,12-octadecadienal (I), (9
Z,12
Z,15
Z)-9,12,15-octadecatrienal (II),
cis-9,10-epoxy-(3
Z,6
Z)-3,6-henicosadiene (III), and
cis-9,10-epoxy-(3
Z,6
Z)-1,3,6-henicosatriene (IV). Although
13C-labeled linolenic acid was not converted into trienal II at the pheromone glands of
H. cunea females, GC-MS analysis of an extract of the pheromone gland treated topically with
13C-labeled linolenyl alcohol showed the aldehyde incorporating the isotope. Other C
18 and C
19 fatty alcohols were also oxidized to the corresponding aldehydes in the pheromone gland, indicating a biosynthetic pathway of II via linolenyl alcohol and low substrate selectivity of the alcohol oxidase in the pheromone gland. On the other hand, epoxydiene III was expected to be produced by specific 9,10-epoxidation of the corresponding C
21 trienyl hydrocarbon, which might be biosynthesized from dietary linolenic acid in oenocytes and transported to the pheromone gland. The final biosynthetic step in the pheromone gland was confirmed by an experiment using deuterated C
21 triene, which was synthesized by the chain elongation of linolenic acid and LiAlD
4 reduction as key reactions. When the labeled triene was administered to the female by topical application at the pheromone gland or injection into the abdomen, deuterated III was detected in a pheromone extract by GC-MS analysis. Furthermore, the substrate selectivity of epoxidase and selective incorporation by the pheromone glands were examined by treatments with mixtures of the deuterated precursor and other hydrocarbons such as C
19-C
23 trienyl, C
21 dienyl, and C
21 monoenyl hydrocarbons. The 9,10-epoxy derivative of each alkene was produced, while the epoxidation of the C
21 monoene was poorer than those of the trienes and diene. The low selectivity indicated that the species-specific pheromone of the
H. cunea female was mainly due to the critical formation of the precursor of each component.
127 Analyses of lepidopteran sex pheromones by mass spectrometry.
Lepidoptera, including about 150,000 species in the world, comprise the second largest insect group, and sex pheromones have been identified from virgin female moths of more than 600 species. The chemical structures are simple, but diverse, because species-specific pheromones play an important role in the reproductive isolation of each species. The pheromone content in each female is quite low, and gas chromatography coupled to mass spectrometry (GC-MS) is most frequently utilized to reveal the chemical structure. Almost all pheromone components are straight-chain compounds and are classified into two major groups [i.e. unsaturated C
10-C
18 fatty alcohols and their derivatives (Type I) and C
17-C
23 polyenyl hydrocarbons and their epoxides (Type II)]. In addition to the unbranched compounds, some species secrete methyl-branched compounds (e.g., 2-ketones). For the identification of these compounds, determining the positions of the double bond, the epoxy ring, and the methyl group is an important key step. Copious spectral information measured by electron-impact ionization (70 eV) has been accumulated for these compounds. This review therefore deals with their spectral characteristics, namely, diagnostic ions, to apply them to pheromone studies on new target insects.
128 Synthesis and insecticidal activity of 1,2,4-oxadiazole and 1,2,4-thiadiazole derivatives.
A series of 5-substituted 1,2,4-oxadiazoles and 1,2,4-thiadiazoles were prepared as muscarinic acetylcholine receptor agonists and evaluated for their insecticidal activity. These derivatives were synthesized through sequential reactions consisting of the condensation of pyridinecarboamides or pyridinecarbothioamides with
N,N-dimethylacetamide dimethyl acetal, cyclization with hydroxylamine, quaternization by alkyl halide and reaction with sodium borohydride. All 1,2,4-oxadiazoles and 1,2,4-thiadiazoles synthesized were evaluated for insecticidal activity and their structure-activity relationships are discussed. It was discovered that many compounds were active against representative insects such as
Nilaparvata lugens,
Nephotettix cincticeps and
Aphis craccivora. In particular, it was also found that 3-pyridyl-substituted derivatives of 1,2,4-oxadiazole and 1,2,4-thiadiazole exhibited good insecticidal activity against all the insects tested. Among the compounds evaluated, 3-methyl-5-(1,2,5,6-tetrahydropyridin-3-yl)-1,2,4-thiadiazole (9m-2) showed the highest activity against
Nilaparvata lugens, and provided a high level of activity against the imidacloprid-resistant strain. Based on the preliminary binding assay using the binding inhibition of mAChR antagonist [
3H]NMS to the nerve-cord membranes as an index of the binding activity, 9m-2 exhibited a range of potencies for the insect muscarinic receptor.
129 (5R,7R)-5-Methylheptadecan-7-ol: A novel sex pheromone component produced by a female lichen moth, Miltochrista calamina, in the family Arctiidae.
A methyl-branched heptadecanol was found in the pheromone gland extract of a female lichen moth,
Miltochrista calamina (Arctiidae, Lithosiinae). GC-MS analyses of the alcohol and a hydrocarbon derived from it by subsequent treatments with methanesulfonyl chloride and LiAlD
4 in microscale reactions indicated 5-methylheptadecan-7-ol (1) as one possible structure. The four stereoisomers of 1 in a ratio of 4:4:1:1 were prepared from (
S)-β-citronellol with 60% ee, and were separated by a combination of achiral and chiral HPLC columns. The absolute configuration of each isomer was determined by comparison with the chromatographic behaviors of other samples synthesized by a different scheme, which applied the Jacobsen hydrolytic kinetic resolution of racemic 1,2-epoxydodecane to fix the configuration of the 7-hydroxy group. Only the (5
R,7
R)-isomer attracted male moths; thus, we concluded that
M. calamina females secrete (5
R,7
R)-1 as a sex pheromone, indicating a new chemical class of lepidopteran female sex pheromones.
130 Biosynthetic pathway for sex pheromone components produced in a Plusiinae moth, Plusia festucae.
While many Plusiinae species commonly secrete (
Z)-7-dodecenyl acetate (Z7-12:OAc) as a key pheromone component, female moths of the rice looper (
Plusia festucae) exceptionally utilize (
Z)-5-dodecenyl acetate (Z5-12:OAc) to communicate with their partners. GC-MS analysis of methyl esters derived from fatty acids included in the pheromone gland of
Plusia festucae showed a series of esters monounsaturated at the ω7-position, i.e., (
Z)-5-dodecenoate, (
Z)-7-tetradecenoate, (
Z)-9-hexadecenoate (Z9-16:Me), and (
Z)-11-octadecenoate (Z11-18:Me). By topical application of D
3-labled palmitic acid (16:Acid) and stearic acid (18:Acid) to the pheromone glands, similar amounts of D
3-Z5-12:OAc were detected. The glands treated with D
13-labeled monoenoic acids (Z9-16:Acid and Z11-18:Acid), which were custom-made by utilizing an acetylene coupling reaction with D
13-1-bromohexane, also produced similar amounts of D
13-Z5-12:OAc. These results suggested that Z5-12:OAc was biosynthesized by ω7-desaturase with low substrate specificity, which could introduce a double bond at the 9-position of a 16:Acid derivative and the 11-position of an 18:Acid derivative. Additional experiments with the glands pretreated with an inhibitor of chain elongation supported this speculation. Furthermore, a comparative study with another Plusiinae species (
Chrysodeixis eriosoma) secreting Z7-12:OAc indicated that the β-oxidation systems of
P. festucae and
C. eriosoma were different.
131 Identification and field evaluation of sex pheromone components of the pear barkminer moth, Spulerina astaurota.
The pear barkminer moth,
Spulerina astaurota Meyrick (Gracillariidae: Gracillariinae), is a harmful pest of the Asian-pear tree. Pheromone components of the female were analyzed by gas chromatography (GC) with an electroantennographic (EAG) detector and GC coupled with mass spectrometry. The analyses of a crude pheromone extract and those of a fractionated extract on a Florisil column indicated three EAG-active components, tetradecadien-1-ol, its acetate, and an aldehyde derivative. Characteristic fragment ions in the mass spectra of the dienyl compounds and derivatives with 4-methyl-1,2,4-triazoline-3,5-dione revealed double bonds at the 9- and 11-positions. By comparing the chromatographic behaviors to those of four authentic geometrical isomers, which were synthesized by three different routes starting from 1,8-octanediol or 1,9-nonanediol, the configuration of each natural component was assigned to be 9Z,11Z; i.e., it was concluded that the
S. astaurota females secreted (9
Z,11
Z)-9,11-tetradecadien-1-ol (Z9,Z11-14:OH) as a main pheromone component, and the acetate and aldehyde derivatives (Z9,Z11-14:OAc and Z9,Z11-14:Ald) as minor components. This identification was confirmed by a field evaluation of the synthetic pheromone. While the male moths could be attracted to a lure baited with Z9,Z11-14:OH alone, Z9,Z11-14:OAc showed a strong synergistic effect on the attraction. Among the lures tested, the mixture of alcohol and acetate in a ratio of 7:3 exhibited the strongest attraction. Addition of Z9,Z11-14:Ald in the mixture did not significantly increase the number of males attracted. Furthermore, the field test indicated that some contamination of a geometrical isomer of the alcohol did not impair the activity of the binary mixture with the 9Z,11Z configuration.
132 Female sex pheromone of Cystidia couaggaria couaggaria (Lepidoptera: Geometridae): identification and field attraction.
The plum cankerworm moth,
Cystidia couaggaria couaggaria (Geometridae: Ennominae), is a defoliator of Chinese plum trees (
Prunus mume). The pheromone components of the female were analyzed by gas chromatography (GC) with an electro-antennographic (EAG) detector and GC coupled with mass spectrometry. The crude pheromone extract included several EAG-active components, i.e., trienyl, dienyl, and saturated hydrocarbons, with a C
21-C
25 straight chain. The characteristic mass spectra indicated the unsaturated hydrocarbons to be (
3Z,6Z,9Z)-3,6,9-trienes and (6
Z,9
Z)-6,9-dienes. In the fields, mixtures of the synthetic C
21 and C
23 trienes in a ratio of 2:3 and 1:4 successfully attracted males of this diurnal species during daytime. While the male antennae responded to the C
25 triene and saturated hydrocarbons, their synergistic effects were not observed on the male attraction in the fields. Addition of the C
21 diene interestingly inhibited the activity of the triene mixture. Males of
Cystidia truncangulata, a sympatric diurnal congener of
C. c. couaggaria, showed similar EAG responses to the unsaturated hydrocarbons, but no
C. truncangulata males were attracted by the lures tested or
C. c. couaggaria males, indicating that the identified hydrocarbons comprised the species-specific pheromone of
C. c. couaggaria females.
133 Stereospecific inversion of secondary tosylates to yield chiral methyl-branched building blocks which were applied to the asymmetric synthesis of leafminer sex pheromones.
All four of the possible stereoisomers of 5,9-dimethylheptadecane, the major sex pheromone component secreted by female moths of the mountain-ash bentwing (
Leucoptera scitella), were synthesized by the coupling of two chiral blocks with a methyl branch at the 2- or 3-position. The blocks were prepared by applying the stereospecific inversion of secondary tosylates, which were derived from (
R)- and (
S)-propyleneoxide, and their enantiopurities were confirmed by chiral HPLC analysis.
134 Identification and field evaluation of sex pheromones of two hawk moths, Deilephila elpeno lewisii (Btuler) and Theretra oldenlandiae oldenlandiae (Fabricius).
The sex pheromones of two species of hawk moth,
D. elpenor lewisii (Btuler) and
Theretra oldenlandiae oldenlandiae (Fabricius) were analyzed by means of gas chromatography-electroantenographic detection (GC-EAD) and GC-mass spectrometry (GC-MS). Three EAD-active components, (
E)-11-hexadecenal (E11-16:Ald), (
E,E)-10,12-hexadecadienal (E10E12-16:Ald) and (or) (
E,Z)-10,12-hexadecadienal (E10Z12-16:Ald) were found in their pheromone gland extracts. In field trap tests, male moths of
D. e. lewisii were attracted to a binary blend of E11-16:Ald and E10E12-16:Ald at a ratio of 85:15, while males of
T. o. oldenlandiae were attracted to a ternary blend of E11-16:Ald, E10Z12-16:Ald and E10E12-16:Ald at a ratio of 30:40:30. No males of both species were attracted to any single components. We, therefore, concluded that sex pheromone of
D. elpenor lewisii is a mixture of E11-16:Ald and E10E12-16:Ald, and that of
T. o. oldenlandiae was E11-16:Ald, E10Z12-16:Ald and E10Z12-16:Ald.
135 Characterization of epoxytrienes derived from (3Z,6Z,9Z)-1,3,6,9-tetraenes, sex pheromone components of arctiid moths and related compounds.
Cis-9,10-epoxy-(
3Z,6Z)-1,3,6-henicosatriene has been identified from a pheromone gland of arctiid species, such as
Hyphantria cunea. Since the diversity of lepidopteran species suggests that structurally related compounds of the 9,10-epoxide are also utilized as a sex pheromone components, epoxytrienes derived from (
3Z,6Z,9Z)-1,3,6,9-tetraenes with a C
19-C
21 chain were systematically synthesized and characterized. While 1,2-epoxy-3,6,9-triene was not obtained, peracid oxidation of each tetraene produced a mixture of three
cis-epoxides (3,4-epoxy-1,6,9-triene, 6,7-epoxy-1,3,9-triene, and 9,10-epoxy-1,3,6-triene), which were separable by LC as well as GC. Detailed inspection of the mass spectra of the C
19-C
21 epoxides indicated the following diagnostic ions for determining the chemical structures:
m/z 79, M-70, and M-41 for the 3,4-epoxytrienes;
m/z 79, 95, 109, and 149 for the 6,7-epoxytrienes; and
m/z 79, 106, 120, M-121, and M-107 for the 9,10-epoxytrienes. Resolution of two enantiomers of each C
21 epoxytriene was accomplished by HPLC equipped with a chiral column, and analysis of the pheromone extracted from virgin females of
H. cunea revealed the
9S,10R configuration of the natural epoxytriene as the same configuration of C
21 9,10-epoxydiene, a main pheromone component of this species. GC-EAD analysis of the optically pure epoxides showed that the antennae of male
H. cunea were stimulated more strongly (100 times) by the (
9S,10R)-isomers than the antipodes.
136 Unsaturated cuticular hydrocarbons synergise responses to the sex attractant pheromone in the yellow peach moth.
Four trienyl hydrocarbons, (
Z3,Z6,Z9)-tricosatriene (Z3,Z6,Z9-23:HC), (
Z3,Z6,Z9)-pentacosatriene (Z3,Z6,Z9-25:HC), (
Z3,Z6,Z9)-heptacosatriene (Z3,Z6,Z9-27:HC) and (
Z3,Z6,Z9)-nonacosatriene (Z3,Z6,Z9-29:HC) were identified in the non-polar fraction of the body wax of male and female yellow peach moths. Their synergistic effects when combined with aldehyde sex attractant pheromone components were assessed with wind tunnel tests. The relative amounts and ratios of these hydrocarbons differed between males and females. In females, the ratios in body wax and crude pheromone gland extracts were similar, but lesser amounts were found in the gland extracts. Among the hydrocarbons, only Z3,Z6,Z9-23:HC strongly synergized the known pheromone blend of (
E)-10-hexadecenal (E10-16:Ald) and (
Z)-10-hexadecenal (Z10-16:Ald). Z3,Z6,Z9-23:HC and (
Z9)-heptacosene (Z9-27:HC) also additively increased responses to the blend of aldehyde pheromone components. The total activity of the mixture of the aldehydes with these two unsaturated hydrocarbons was similar to that of crude pheromone extracts. A positive dose response relationship between the aldehyde components and all trienyl hydrocarbons mixtures was found. The lowest doses for synergism of the two components and the unsaturated hydrocarbons mixture were respectively 10-1 and 10-2 female equivalent (body wax extracts). During calling, Z3,Z6,Z9-23:HC and Z9-27:HC released from a female's body wax may work in combination with the aldehydes from the pheromone gland to efficiently elicit copulation behavior by male moths.
137 Female sex pheromone secreted by Carmenta mimosa (Lepidoptera: Sesiidae), a biological control agent for an invasive weed in Vietnam.
Larvae of a clearwing moth,
Carmenta mimosa (Lepidoptera: Sesiidae), bore into the trunk of
Mimosa pigra L., which is one of the most invasive weeds in Vietnam. GC-EAD and GC-MS analyses of a pheromone gland extract revealed that the female moths produced (
3Z,13Z)-3,13-octadecadienyl acetate. In the field, a lure baited with the synthetic acetate alone successfully attracted the
C. mimosa males. While addition of a small amount of the corresponding alcohol did not strongly diminish the number of captured males, a trace of the aldehyde derivative or the (
3E,13Z)-isomer remarkably inhibited the attractiveness of the acetate. The diurnal males were mainly attracted from 6:00 am to 12:00 am.
138 Identification of the sex pheromone secreted by Synanthedon tenuis (Lepidoptera: Sesiidae).
The Japanese persimmon treeborer,
Synanthedon tenuis (Butler) (Lepidoptera: Sesiidae), is a harmful pest of persimmon trees (
Diospyros spp.). Because males of this species are known to be attracted by (
3Z,13Z)-3,13-octadecadienyl acetate (Z3,Z13-18:OAc), a mating disruptant composed of a 1:1 mixture of Z3,Z13-18:OAc and the (
3E,13Z) isomer, the original target of which is an allied pest,
S. hector (Butler), has been diverted to control
S. tenuis. However, the sex pheromone secreted by
S. tenuis females has not been characterized. Analyses of pheromone gland extracts using gas chromatography (GC) equipped with an electroantennographic detector (GC-EAD) and GC combined with mass spectrometry (GC-MS) detected only Z3,Z13-18:OAc, and no other known sesiid pheromone components were found. In a persimmon orchard,
S. tenuis males were selectively attracted by a lure baited with Z3,Z13-18:OAc among four geometrical isomers of 3,13-octadecadienyl acetate, indicating that males strictly discriminated among the configurations of the two double bonds. Lures baited with single Z3,Z13-18:OAc attracted only
S. tenuis. Further field experiments revealed that the attractiveness of Z3,Z13-18:OAc is significantly inhibited by the addition of the (
3E,13Z) isomer or the parent alcohol.
139 Propionates and acetates of chiral secondary alcohols: novel sex pheromone components produced by a lichen moth Barsine expressa (Arctiidae: Lithosiinae).
Females of a lichen moth,
Barsine expressa (Arctiidae, Lithosiinae), which inhabit Iriomote Island in Japan, were captured by a black-light trap, and the pheromone gland extract was analyzed by gas chromatography (GC) with an electroantennographic (EAG) detector, and by GC coupled with mass spectrometry. The females produced several EAG-active esters, and the mass spectrum of a major component indicated the mixture consists of propionates derived from C
17-saturated secondary alcohols, which were inseparable on the capillary GC column. In addition to these main components, the pheromone glands included two acetate derivatives of C
17 alcohols, and other propionates of C
16 and C
15 alcohols. The crude extract was treated with K
2CO
3, and a 1:1 mixture of C
17 alcohols with a C
6- or C
7-chain moiety was obtained. The two alcohols were uniformly converted into monodeuterated
n-heptadecane by mesylation and succeeding LiAlD
4 reduction. This result revealed a straight-chain structure of the C
17 alcohols with the acyl groups located at the 7- or 8-position. Field tests on Iriomote Island showed that the synthetic esters were behaviorally active. A 1:1 mixture of racemic 7-propioxyheptadecane and 8-propioxyheptadecane, which were prepared from the secondary alcohols synthesized by a Grignard coupling reaction, attracted male moths. Furthermore, propionates of the alcohols synthesized enantioselectively by using a hydrolytic kinetic resolution with Jacobsen's catalyst were evaluated. Only the traps baited with a mixture of the two esters with the same
S-configuration significantly attracted
B. expressa males. In the Tokyo area, the propionate mixture attracted a closely related species,
Barsine aberrans aberrans.
140 Identification of the sex pheromone secreted by a nettle moth, Monema flavescens, using gas chromatography/Fourier transform infrared spectroscopy.
The nettlemoth
Monema flavescens (Limacodidae) is a defoliator of fruit trees, such as Chinese plum and persimmon. The larvae of this species have spines that contain a poison that causes serious irritation and inflammation in humans. Coupled gas chromatography-electroantennogram detection and gas chromatography/mass spectrometry analyses of a crude pheromone extract, combined with derivatization, indicated that female moths produced 8-decen-1-ol and 7,9-decadien-1-ol at a ratio of approximately 9:1. The
E configuration of the double bonds was assigned for both components from infrared spectra, recorded on a gas chromatograph/Fourier transform-infrared spectrophotometer equipped with a zinc selenide disk cooled to -30 degree. The monoenyl and dienyl alcohols had absorptions characteristic of Egeometry at 966 and 951 cm
-1 , respectively. A band chromatogram at 951 cm
-1 was useful for distinguishing geometric isomers, because terminal conjugated diene are difficult to resolve, even on high polarity columns. Furthermore, we identified the
Z configuration of the same 7,9-dienyl alcohol secreted by another nettle moth,
Parasa lepida lepida , through the absence of this absorption. In field trials, lures baited with a 9:1 mixture of (
E)-8-decen-1-ol and (
E)-7,9-decadien-1-ol attracted
M. flavescensmales. Furthermore, the field trials indicated that contamination with the (
Z)-diene reduced catches to the pheromone mixture more than did contamination with the (
Z)-monoene.
141 Synthesis of all four stereoisomers of 6,10,13-trimethyltetradecan-2-one, a sex pheromone component produced by males of the stink bug Pallantia macunaima.
The stink bug,
Pallantia macunaima (Heteroptera: Pentatomidae), is a soybean pest in southern Brazil, and the males produce 6,10,13-trimethyltetradecan-2-one to communicate with females. All four stereoisomers of the sex pheromone were synthesized by coupling two chiral building blocks, which were synthesized from (
S)- and (
R)- propylene oxides using stereospecific inversion of secondary tosylates as a key reaction. The enantiomeric purities of the building blocks were confirmed by chiral HPLC analysis.
142 (6R,10S)-Pallantione: the first ketone identified as sex pheromone in stink bugs.
This work describes the structural elucidation of the sex pheromone of the soybean stink bug,
Pallantia macunaima The biological activity of the synthetic pheromone was demonstrated by behavioral and EAD experiments. Furthermore, the absolute configuration of the natural pheromone was determined as (
6R,10S)-6,10,13-trimethyltetradecan-2-one. This is the first ketone identified as a male-produced sex pheromone in Pentatomidae, and the trivial name, pallantione, was assigned to this novel pheromone molecule.
143 Sex pheromones of three citrus leafrollers, Archips atrolucens, Adoxophyes privatana and Homona sp. (Lepidoptera: Tortricidae), inhabiting the Mekong Delta of Vietnam.
Archips atrolucens,
Adoxophyes privatana, and
Homona sp. are serious defoliators of citrus trees in the Mekong Delta of Vietnam. In order to establish a sustainable pest-management program for the three species, their female-produced sex pheromones were investigated by GC-EAD and GC-MS analyses, and the following multicomponent pheromones were identified (
Z)-11-tetradecenyl acetate (Z11-14:OAc), (
E)-11-tetradecenyl acetate (E11-14:OAc), and tetradecyl acetate (14:OAc) in a ratio of 64:32:4 for
A. atrolucens ; Z11-14:OAc and (
Z)-9-tetradecenyl acetate (Z9-14:OAc) in a ratio of 92:8 for
A. privatana ; and Z11-14:OAc and (
Z)-9-dodecenyl acetate (Z9-12:OAc) in a ratio of 96:4 for
Homona sp. Each lure baited with synthetic components as a mimic of the natural pheromone attracted males of the target species specifically, indicating that each monounsaturated minor component plays a significant role for mating communication and reproductive isolation of the three species inhabiting the same citrus orchards. In an extract of the pheromone glands of
A. atrolucens females, the content of 14:OAc was very low, but a synergistic effect was observed clearly when the saturated compound was mixed at the same level as the E11-14:OAc. The synthetic lures will provide useful tools for monitoring flights of adults of the three species.
144 Characterization of posticlure and the structure-related sex pheromone candidates prepared by epoxidation of (6Z,9Z,11E)-6,9,11-trienes and (3Z,6Z,9Z,11E)-3,6,9,11-tetraenes.
trans-11,12-Epoxy-(
6Z,9Z)-6,9-henicosadiene (posticlure) has been identified from a pheromone gland of the lymantriid species,
Orgyia postica. Since the diversity of Lepidoptera suggests that some species utilize the structurerelated epoxy compound as a sex pheromone component, epoxydienes and epoxytrienes derived from (
6Z,9Z ,11E)-6,9,11-trienes and (
3Z,6Z,9Z,11E)-3,6,9,11-tetraenes with a C
19-C
21 chain were systematically synthesized and the chemical data were accumulated in order to contribute to a new pheromone research. Peracid oxidation of each triene and each tetraene produced, respectively, a mixture of three epoxydienes (
cis-6,7-epoxy-9,11-diene;
cis-9,10-epoxy- 6,11-diene; and
trans-11,12-epoxy-6,9-diene) and four epoxytrienes (
cis-3,4-epoxy-6,9,11-triene;
cis-6,7-epoxy-3,9,11-triene;
cis-9,10-epoxy-3,6,11-triene; and
trans-11,12-epoxy-3,6,9-triene). While the 9,10-epoxy compounds were unstable and, interestingly, converted into 9-ketone derivatives after chromatography over SiO
2, each positional isomer was isolated by HPLC equipped with an ODS column, and the chemical structure was determined by NMR analysis. On the GC-MS analysis with a DB-23 column, the positional isomers were also eluted separately and characteristic mass spectra were proposed. By comparing the spectral data of the epoxy compounds with a different carbon chain, diagnostic fragment ions reflecting the chemical structure were determined as follows:
m/z 79, 109, 113, and M-114 for the 6,7-epoxydienes;
m/z 69, 97, 111, 139, and M-111 for the 9,10-epoxydienes;
m/z 57, 79, 109, 136, M-151, and M- 111 for the 11,12-epoxydienes;
m/z 79, 91, 105, and 119 for the 3,4-epoxytrienes;
m/z 79, 124, M-124, M-96, and M-69 for the 6,7-epoxytrienes;
m/z 79, 95, 109, 137, and M-108 for the 9,10-epoxytrienes; and
m/z 79, 134, M-149, M-109, and M-95 for the 11,12-epoxytrienes.
145 Synthesis of four stereoisomers of (S)-2-methylpent-3-yl 3,13-dimethylpentadecanoate, a sex pheromone of the bagworm moth Clania variegate, using stereospecific inversion of secondary sulfonates as a key step.
Females of some lepidopteran species produce novel sex pheromones with a methyl-branched structure, such as 2-methylpent-3-yl 3,13-dimethylpentadecanoate secreted by the bagworm moth
Clania variegate. Recently, we have established a simple preparative method for the synthesis of methyl-branched building blocks by utilizing an SN
2 reaction of chiral secondary tosylates derived from (
S)-and (
R)- propyleneoxides. The usefulness of these building blocks was demonstrated by their application in the synthesis of all four stereoisomers of an acid moiety in the bagworm pheromone. The enantiomeric purities of all building blocks were confirmed by enantioselective HPLC analysis. We found that a secondary mesylate was superior to the corresponding tosylate because it avoided an elimination side reaction, and racemization in the SN
2 reaction was not observed even at high temperature (150°C). Finally, each optically active acid was esterified with (
S)-2-methyl-3-pentanol, which was synthesized by a new route starting from (
S)-valine.
146 Identification of conjugated pentadecadienals as sex pheromone components of the sphingid moth, Dolbina tancrei.
Homologs of bombykal, (
10E,12Z)-10,12-hexadecadienal, have been reported to be sex pheromones or sexual attractants of several species of sphingid moths. In this study, we identified novel bombykal analogs as sex pheromone components from a Japanese sphingid moth,
Dolbina tancrei Staudinger (Sphingidae: Lepidoptera). Sex pheromone gland extracts from calling female moths were subjected to gas chromatography/electroantennograhic detection (GC/EAD), gas chromatography/mass spectrometry (GC/MS), and gas chromatography (GC) analyses. GC/EAD analyses showed two active components in the crude pheromone extracts. GC/MS analysis determined these two components to be pentadecadienals. GC/MS of their MTAD derivatives showed conjugated double bonds at the 9- and 11-positions, indicating 9,11-pentadecadienals. The isomeric configurations of these candidates were determined by comparison of their Kovats retention indices with those of synthetic compounds. Field bioassays with the four isomers of 9,11-pentadecadienal and their mixtures confirmed that the two sex pheromone components of
D. tancrei are (
9E,11Z,9Z)-9,11-pentadecadienal and (
9Z,11Z)-9,11-pentadecadienal, with the highest male catches observed for a 90:10 blend. This is the first report of 9,11-pentadecadienals as sex pheromone components in lepidopteran species.
147 Discovery of a disused desaturase gene from the pheromone gland of the moth Ascotis selenaria, which secretes an epoxyalkenyl sex pheromone.
Female
Ascotis selenaria (Geometridae) moths use 3,4-epoxy- (
Z,Z)-6,9-nonadecadiene, which is synthesized from linolenic acid, as the main component of their sex pheromone. While the use of dietary linolenic or linoleic fatty acid derivatives as sex pheromone components has been observed in moth species belonging to a few families including Geometridae, the majority of moths use derivatives of a common saturated fatty acid, palmitic acid, as their sex pheromone components. We attempted to gain insight into the differentiation of pheromone biosynthetic pathways in geometrids by analyzing the desaturase genes expressed in the pheromone gland of
A. selenaria. We demonstrated that a Δ11-desaturase-like gene (Asdesat1) was specifically expressed in the pheromone gland of
A. selenaria in spite of the absence of a desaturation step in the pheromone biosynthetic pathway in this species. Further analysis revealed that the presumed transmembrane domains were degenerated in Asdesat1. Phylogenetic analysis demonstrated that Asdesat1 anciently diverged from the lineage of Δ11-desaturases, which are currently widely used in the biosynthesis of sex pheromones by moths. These results suggest that an ancestral Δ11-desaturase became dysfunctional in
A. selenaria after a shift in pheromone biosynthetic pathways.
148 Synthesis and field evaluation of stereoisomers and analogues of 5-methylheptadecan-7-ol, an unusual sex pheromone component of the lichen moth, Miltochrista calamine.
Females of the lichen moth,
Miltochrista calamine (Arctiidae, Lithosiinae), were previously shown to produce 5-methylheptadecan-7-ol (1) as a sex pheromone. In field tests, males were attracted only by the (
5R,7R)-isomer of the four stereoisomers that were prepared by separation from two mixtures of diastereoisomers. A new route to (
5R,7R)-1 starting from (
S)-propylene oxide was developed utilizing the SN
2 reaction of an optically active secondary tosylate and the Jacobsen hydrolytic kinetic resolution of an epoxide intermediate as key steps. Enantioselective HPLC analysis of the product and the antipode synthesized from (
R)-propylene oxide confirmed their high enantiomeric excess (> 99 %). Using this stereospecific synthesis, six analogues with the same configuration as (
5R,7R)-1 but with different alkyl chain(s) connected to the stereogenic centers were prepared in order to obtain GC/MS data and to examine the ability of
M. calamina males to discriminate between them. The mass spectra of the synthetic analogues revealed characteristic fragment ions derived by cleavage around the methyl group in addition to that at the hydroxyl group. In field trapping tests, five out of the six compounds were attractive to male
M. calamina moths, indicating that the males distinguished the configurations of methyl and hydroxyl groups but were less able to perceive differences in the lengths of the two alkyl chains in the pheromone.
149 Enantiospecific synthesis and filed evaluation of four stereoisomers of 10,14-dimethyloctadec-1-ene, a sex pheromone component secreted by female moths of the apple leafminer.
All four stereoisomers of 10,14-dimethyloctadec-1-ene, a sex pheromone component of the apple leafminer (
Lyonetia prunifoliella: Lepidoptera), were synthesized starting from (
R)- and (
S)-propylene oxide by applying stereospecific inversion of chiral secondary tosylates as a key step. Field evaluation showed that male moths of the Japanese population were selectively attracted by the (
10S,14S)-isomer and that the activity was not inhibited by the enantiomer.
150 Reexamination of the female sex pheromone of the sweet potato vine borer moth: identification and field evaluation of a tricosatriene.
The sweet potato vine borer moth,
Omphisa anastomosalis (Pyraloidea: Crambidae), is a serious pest in tropical and subtropical Asia-Pacific regions. In previous work using a population from Okinawa, Japan, (
10E,14E)-10,14-hexadecadienal (E10,E14-16:Ald) was identified as the major pheromone component, with hexadecanal, (
E)-10-hexadecenal, and (
E)-14-hexadecenal as minor components. However, traps baited with the synthetic compounds were less effective at attracting males in the field than those baited with virgin females. While Pyraloidea females usually produce only Type I pheromone components (unsaturated fatty alcohols and their derivatives), the pheromones of some Pyraloidea species have been shown to involve a combination of both Type I and Type II components (unsaturated hydrocarbons and their epoxides). We examined an extract of the pheromone glands of female
O. anastomosalis from Vietnam by gas chromatography coupled to mass spectrometry and detected (
3Z,6Z,9Z)-3,6,9-tricosatriene (Z3,Z6,Z9-23:H) in addition to the compounds identified previously. All four isomers of 10,14-16:Ald were synthesized. A mixture of synthetic E10,E14-16:Ald and Z3,Z6,Z9-23:H in a ratio of 1:0.2-1:2 was attractive to male moths in Vietnam, indicating the strong synergistic effect of the Type II compound. Addition of the other minor pheromone components to the binary blend did not increase the number of male moths captured. Combinations of Z3,Z6,Z9-23:H with the other three geometrical isomers of E10,E14-16:Ald attracted no males, further substantiating the 10E,14E configuration of the natural diene component. E10,E14-16:Ald mixed with other polyunsaturated hydrocarbons showed that mixtures that included a C
21 triene, a C
22 triene, or a C
23 pentaene attracted as many males as did the mixture with Z3,Z6,Z9-23:H. The identification of a highly attractive sex pheromone will help in developing efficient strategies for monitoring and control of
O. anastomosal is populations in sweet potato fields.
151 Carbonyl reduction in the biosynthesis of amale sex pheromone secreted by the grape borer Xylotrechus pyrrhoderus.
Males of the cerambycid beetle
Xylotrechus pyrrhoderus release a mixture of (
S)-2-hydroxy-3-octanone [(
S)-1] and (
2S,3S)-2,3-octanediol [(
2S,3S)-2] as a sex pheromone that attracts conspecific females. The chemical structures of these pheromone components include a common motif and are assumed to be biosynthetically related. Here, we show that deuterated (
S)-1, applied on the cuticle of a pronotal pheromone gland, was converted into (
2S,3S)-2, that included deuterium atoms, but a reverse conversion did not take place. These results reveal a carbonyl reductase to be active in the pheromone gland, and that the ketol is a biosynthetic precursor of the diol. Males did not produce (
R)-1; however, deuterated (
R)-1 was converted into (
2R,3R)-2, indicating an attack of the enzyme from the opposite side of the hydroxyl group at the 2-position. Furthermore, to understand the substrate specificity of the enzyme, racemates of 2-hydroxy-3-hexanone and 2-hydroxy-3-decanone were synthesized and applied to the gland. Their conversion into the corresponding diols suggests that the enzyme reduces the carbonyl group at the 3-position, regardless of the chain length.
152 CYP341B14: A cytochrome P450 involved in the specific epoxidation of pheromone precursors in the fall webworm Hyphantria cunea.
Two of the four sex pheromone components in the fall webworm
Hyphantria cunea (Lepidoptera: Arctiidae),
cis-9,10-epoxy-(
3Z,6Z)-3,6-henicosadiene and
cis-9,10-epoxy-(
3Z,6Z)-1,3,6-henicosatriene, possess an epoxy ring within their molecules. These compounds have been suggested to be biosynthesized from dietary linolenic acid via the following enzymatic reactions; chain elongation, terminal desaturation (in the case of the latter component), decarboxylation, and epoxidation. The last step of this biosynthesis, epoxidation, is known to occur specifically in the sex pheromone gland of females. We identified the enzyme involved in the epoxidation of pheromone precursors by focusing on cytochromes P450, which are known to catalyze the oxidation of various compounds. Three P450-like sequences (Hc_epo1, Hc_epo2, and Hc_epo3) were identified in the cDNA library prepared from the sex pheromone gland of
H. cunea. Among these clones, only Hc_epo1 was specifically expressed in the pheromone gland. The full-length sequence of Hc_epo1 contained an ORF of 1527 bp, which encoded a protein of 509 amino acids with a predicted molecular weight of 57.9 kDa. The deduced Hc_epo1 amino acid sequence possessed the characteristics of P450. A phylogenetic analysis of the sequence indicated that Hc_epo1 belonged to the CYP341B clade in the CYP341 family. Therefore, it was named CYP341B14. A subsequent functional assay using Sf-9 cells transiently expressing CYP341B14 demonstrated that this P450 protein was able to specifically epoxidize a (
Z)-double bond at the 9 position in the pheromone precursor, (
3Z,6Z,9Z)-3,6,9-henicosatriene.
