| 91. |
|
|
| 92. |
|
|
| 93. |
- Martini, A., et al.
(författare)
-
Mating disruption of the pine sawfly Neodiprion sertifer (Hymenoptera. Diprionidae) in isolated pine stands
- 2002
-
Ingår i: Agricultural and Forest Enthomology. - : Wiley. - 1461-9555 .- 1461-9563. ; 4:3, s. 195-201
-
Tidskriftsartikel (refereegranskat)abstract
- 1. Previous applications of the mating disruption technique to Neodiprion sertifer resulted in decreased numbers of males caught in the treated area but no effect on sex ratio or overall population density. 2. The present study assessed the efficacy of mating disruption against N. sertifer outbreaks in pine stands surrounded by agricultural areas or pasture, and therefore isolated from other infested areas. 3. Pine stands were treated by placing dispensers with an erythro-mixture of the acetate ester of 3,7-dimethyl-2-pentadecanol every 10 m in a grid. 4. The efficacy of this technique was evaluated by comparing the number of males caught in sticky traps baited with synthetic pheromone, and by comparing the sex ratio and the population density of the sawfly in the subsequent generation between treated and control pine stands. 5. The number of males caught within treated areas was significantly lower than in the control area. 6. In the treated pine stands 46% of the egg clusters resulted in male cocoons only, compared to 3% of the clusters in the control stand. 7. A significant reduction of the sawfly population was observed in the treated pine stands. The results contrast to the earlier mating disruption attempts with N. sertifer and can probably be ascribed to the isolation of the experimental stands.
|
|
| 94. |
|
|
| 95. |
- Nordin, Ove, et al.
(författare)
-
Kinetic Resolution of Primary 2-methylalcohols via Pseudomonas cepacia Lipase Catalysed Enantioselective Acylation
- 2000
-
Ingår i: Journal of The Chemical Society. Perkin Transactions 1. - : Royal Society of Chemistry (RSC). - 1472-7781 .- 1470-4358 .- 1364-5463. ; , s. 367-376
-
Tidskriftsartikel (refereegranskat)abstract
- The enantioselectivities of lipases from Pseudomonas cepacia (PFL, Amano PS, etc.) towards a series of primary 2-methyl-substituted alcohols using vinyl acetate as the acyl donor in transesterifications in organic solvents were studied. In terms of enantioselectivity, the best results were found for 3-aryl-2-methylpropan-1-ols with enantiomeric ratios (E-values) over 100 in most cases, whereas other 3-substituted primary 2-methylpropan-1-ols generally displayed lower enantioselectivities: 3-cycloalkyl-2-methylpropan-1-ols (E ≈ 20) and 2-methylalkan-1-ols (E ≈ 10). Moving the aryl group closer or further away from the chiral centre resulted in low enantioselectivities: 2-arylpropan-1-ols (E < 10), 2-methyl-4-(2-thienyl)butan-l-ol (E = 12), 2-methyl-5-(2-thienyl)pentan-l-ol (E=3.2) and 2-methyl-6-(2-thienyl)hexan-l-ol (E=3.8).
|
|
| 96. |
|
|
| 97. |
|
|
| 98. |
|
|
| 99. |
- Schlyter, F, et al.
(författare)
-
Carvone and less volatile analogues as repellent and deterrent antifeedants against the pine weevil, Hylobius abietis
- 2004
-
Ingår i: Journal of applied entomology. - : Wiley. - 0931-2048 .- 1439-0418. ; 128:9-10, s. 610-619
-
Tidskriftsartikel (refereegranskat)abstract
- The monoterpenoid carvone (1) has been shown to have strong antifeedant effects on Hylobius spp. However, because of the high volatility of carvone, long-time protection of conifer seedlings in the field using this compound has not been possible. We demonstrate, in several bioassay steps, that less-volatile, heavier analogues retain their pre-ingestive feeding inhibition activity in the large pine weevil, Hylobius abietis (L.) for a longer time. The first step in the evaluation of the biological activity of 12 carvone analogues was a micro-assay, a choice test lasting 4 h. Compounds active at 100 nmol/cm(2) were further dose-response tested to give the effective dose needed to inhibit feeding by 50% (ED50). Of the 14 compounds tested, including both carvone enantiomers, seven heavier analogues were active at low doses (had low ED50 values). As expected from their lower vapour pressure compared with carvone, the heavier analogues proved more resistant to evaporation before testing. Thus, whereas the effect of 8-hydroxy-p-menth-en-6-one 4 declined after 2 days, some of the compounds with high molar masses, such as the alkylhydroxymenthenones 6 and 8, retained a stable activity for 4 days. The retained activity at 4 days was strongly correlated to molecular mass and boiling point. When tested on natural material (host Pinus sylvestris L. twig sections for 48 h), the heavier analogues showed a rather low activity. Probably, the activity of the more volatile compound carvone (1) is due to a repellent effect (olfactory mode) rather than the deterrent effects (gustatory mode) of the heavier compounds. In agreement with the relatively low activity on twigs in the laboratory, the hydroxymenthenone 4 was not active in the field when tested for 2 months as a 1 : 9 mixture with a polar wax.
|
|
| 100. |
- Smitt, Olof, et al.
(författare)
-
Chemoselective additions of thiophenol to carvone and perillaldehyde
- 2002
-
Ingår i: Journal of Chemical Research. Synopses. - 0308-2342. ; 2002:11, s. 527-528
-
Tidskriftsartikel (refereegranskat)abstract
- Depending on the reaction conditions addition of thiophenol can be directed to either of the two C=C-double bonds of the monoterpenes carvone and perillaldehyde.
|
|
