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- Hansson, B. S., et al.
(author)
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Sex pheromone perception in male pine sawflies, Neodiprion sertifer (Hymenoptera; Diprionidae)
- 1991
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In: Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology. - 0340-7594. ; 168:5, s. 533-538
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Journal article (peer-reviewed)abstract
- Electroantennographic and single sensillum recordings were performed on male pine sawfly, Neodiprion sertifer, antennae. Responses to the sex pheromone component (2S, 3S, 7S)- 3,7-dimethyl-2-pentadecenyl (diprionyl) acetate (SSS:OAc), to the behavioral inhibitor (2S, 3R, 7R)-diprionyl acetate (SRR:OAc), to the six other enantiomers of diprionyl acetate, and to the biosynthetic precursor diprionol were recorded. Responses to trans-perillenal, a monoterpene identified in female gland extracts and to (2S, 3S, 7S)-diprionyl propionate (SSS:OPr), a field attractant for N. sertifer and some related sawfly species were also recorded. EAG recordings demonstrated a high antennal sensitivity to SSS:OAc and to SSS:OPr. A somewhat lower response was elicited by SRR:OAc. Single sensillum recordings revealed 8–12 different cells firing in each sensillum, corresponding to the number of cells observed in earlier morphological investigations. Out of these cells all, except one, responded to SSS:OAc and to SSS:OPr. No differences in the response to the two components could be observed. The largest amplitude cell in each sensillum was specifically tuned to the behavioral antagonist, SRR:OAc. The pheromone perception system encountered in male pine sawflies thus differs clearly from that observed in moths.
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- Hedenström, Erik, et al.
(author)
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Sex Pheromone of pine sawflies. Chiral syntheses of some active minor components isolated from neodiprion sertifer and of some chiral analogues of diprionyl acetate.
- 1992
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In: Tetrahedron. - 0040-4020. ; 48:15, s. 3139-3146
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Journal article (peer-reviewed)abstract
- The chiral syntheses of some analogues, 2 - 7, of 3,7-dimethyl-2-pentadecanol, 1 (diprionol), and of the corresponding acetates are described. The acetate of 1 is the main attractant in the sex pheromone of the Neodiprion genus (Diprionidae). Compounds 2 /2- 4 were identified as minor components isolated from females of Neodiprion sertifer. Synthetic intermediates were prepared either from chiral starting materials, via asymmetric syntheses, or by baker's yeast reductions.
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- Holmberg, Erland, et al.
(author)
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Reaction conditions for the resolution of 2-methylalkanoic acids in esterification and hydrolysis with lipase from Candida cylindracea
- 1991
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In: Applied Microbiology and Biotechnology. - 0175-7598. ; 35:5, s. 572-578
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Journal article (peer-reviewed)abstract
- We have demonstrated resolution of 2-methylalkanoic acids using lipase from Candida cylindracea as a catalyst. The resolution of 2-methyldecanoic acid was more successful than that of 2-methylbutyric acid both by esterification and hydrolysis. This indicates that the resolution of the acid is dependent on the chain length of the acid moiety. The chain length of the alcohol moiety of the ester affected the resolution of the long-chain acid only. Using esterification, (R)-2-methyldecanoic acid was produced in an enantiomeric excess (e.e.) of 95% (E = 40). If the enantiomeric ratio is low (E = 3.6), as in the resolution of 2-methylbutyric acid, esterification combined with a high equilibrium conversion could be used to yield the remaining acid in a high e.e. In the hydrolytic reactions, the e.e. and the equilibrium conversion were dependent on the pH and the presence of CaCl2. When octyl 2-methyldecanoate was hydrolysed at pH 8.0 in the presence of CaCl2, the (S)-acid was formed with an e.e. of 80% (E = 9), but when the hydrolysis was carried out at pH 7.5 without CaCl2, a very low e.e. and a low equilibrium conversion were observed. The latter conditions allowed the esterification of 2-methyldecanoic acid with 1-octanol even in aqueous medium.
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- Högberg, Hans-Erik, et al.
(author)
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Biocatalysis as a useful tool in pheromone synthesis. Enantiomerically pure building blocks from baker's yeast reductions and enzyme catalysed resoluti
- 1994
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In: Catalysis Today. - : Elsevier BV. - 0920-5861. ; 22:3, s. 591-606
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Journal article (peer-reviewed)abstract
- Biocatalytical methods are presented which provide useful building blocks for pheromone synthesis. Examples of the utility of this approach are the preparation of building blocks for the synthesis of stereochemically pure isomers of pine sawfly pheromones and some other pheromones. Enantiom- erically pure ( 98% ee) 2-methyl-1-alkanols 2 were obtained via baker's yeast reduction of suitable α,β-unsaturated aldehydes, and by using lipases from Pseudomonas to effect resolution by transesterification of suitable racemic precursors to 2-methyl-1-alkanols 2 which gave high enantiomeric ratios E > 100. The resolution by esterification mediated by lipase from Candida rugosa of racemic 2-methylalkanoic acids also gave high enantiomeric ratios E> 100 after having improved the reaction conditions by regulating water activity, by choice of the appropriate complimentary substrate alcohol and by adjusting the initial equivalents of the latter present at the start. Also discussed is the separation of diastereomers of diprionol 1, which is naturally occurring in the pine sawfly Neodiprion sertifer, where it is the direct precursor of its pheromone.
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- Wassgren, Ann Britt, et al.
(author)
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Pheromone related compounds in pupal and adult female pine sawflies, Neodiprion sertifer, of different age and in different parts of the body
- 1992
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In: Journal of Insect Physiology. - 0022-1910. ; 38:11, s. 885-893
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Journal article (peer-reviewed)abstract
- The pine sawfly pheromone precursor 3,7-dimethyl-2-pentadecanol (diprionol) was quantified by gas chromatography in different body parts of virgin female Neodiprion sertifer. About one-third of the total amount (approx. 10 ng per female) was found in each of head + thorax, abdominal segments 1-3, and the remaining abdomen. Diprionol was also found in the respective parts of pupae, but in lower amounts. This suggests that at least the final steps of the pheromone biosynthesis take place in many parts of the body, possibly in the cuticle. The diprionol content remained relatively constant over the whole lifetime of virgin females. By using coupled gas chromatography-electroantennogram detection three active compounds in the acetylated female extract were observed. These corresponded to the pheromone, (2S,3S,7S)-diprionyl acetate, and its homologues with the chain shortened by one and two carbons respectively, as determined by gas chromatography-mass spectrometry. In addition, the homologue having a chain elongated by one carbon was found. The homologues occurred in amounts of 2-5% of the diprionyl acetate. When synthetic homologues were tested in the field, alone or in combination with diprionyl acetate, they were not behaviourally active to male sawflies, despite their electroantennogram activity. A threo-isomer of diprionol, most likely (2S,3R,7R), was present in the females in amounts less than 0.5% of the (2S,3S,7S)-content. The acetate of this threo-isomer is known as both synergist and inhibitor to the (2S,3S,7S)-isomer. trans-Perillenal was found in the abdominal segments 1-3 of both males and females and its possible biosynthetic relationship to diprionol is discussed.
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