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The inhibitory activity (I50) of fifteen sulfone analogs of 6-alkylthio-2-pyridyl methanesulfonates was measured against acetylcholinesterase preparations from Ageo and Izumi strains of Nephotettix cincticeps. The insecticidal activity of 6-alkylthio derivatives to both strains was highly related to the acetylcholinesterase-inhibitory activity of the corresponding sulfones when hydrophobicity factors (log h) of the molecule perhaps participating in the transport process were taken into account.Variations in insecticidal activity was due to the total of structure-activity relationships in enzyme inhibition and transport process. The combination of hydrophobicity and steric parameter terms was quite similar in the two strains.

There has been an increasing demand for small-sized (cherry) tomatoes because they contain lycopene and other functional constituents, last for a long period of time, and are delicious to eat. However, since conventional cherry tomato cultivation methods involve guiding the vines upward and downward and other tasks that are labor-intensive, it is necessary to develop new cultivation techniques to save the energy required for cultivation management and reduce the labor required. In 2010, the authors developed a new method for open-field cherry tomato cultivation, in which the seedlings are planted more sparsely compared with conventional cultivation methods and most lateral shoots are left as they are. Although the new cultivation method, which is referred to as the sauvage method, is becoming popular across Japan, no studies have been conducted to compare the yield, quality, and growth rate of tomatoes between the sauvage and conventional cultivation methods. The present study aimed to establish the sauvage cultivation system as a new open-field cultivation method for summer-autumn-harvest cherry tomatoes. Two cherry tomato varieties with different characteristics were raised for two years using the sauvage and conventional cultivation methods, and the results were compared. The total yield and vendible crop yield per stock produced from the sauvage cultivation were larger, compared with conventional cultivation methods. In addition, the yield per area produced from the sauvage cultivation was expected to be equivalent to that from conventional cultivation methods, although the number of stocks per area was approximately one sixth. Furthermore, the sauvage cultivation method prevented the fruit from being sun-damaged. The sugar content of cherry tomatoes produced with sauvage cultivation was the same or lower, and the lycopene content was the same or higher, compared with conventional cultivation methods.

Methanesulfonatesof phenol and hydroxy heteroaromatic compounds possessing an isobutylthio substituent were synthesized and their lethal activity against six species of insects and mites was tested.The insecticidal spectrum and potency of these aryl methanesulfonates varied according to the aromatic moiety. Compounds the aryl moiety of which is phenyl, pyridyl, pyrazinyl and thiazolyl showed high insecticidal activity to N. cincticeps, N. lugens and C. pipiens.For high insecticidal activity, the isobutylthio group was required at the B (meta) position with regard to the sulfonate side chain. The corresponding and sulfones showed high inhibitory activity to acetylcholinesterase preparations from N. cincticeps, housefly heads and bovine erythrocytes. * Structure-Activity Studies of Methanesulfonate Insecticides (Part 5). For Part 4, see Ref. 4).