General trends and strategies for novel pesticides are summarized. Global pesticide sales and pesticide discovery research are also briefly reviewed. At least 105 chemical pesticides have been launched during the past decade or are under development: 43 fungicides, 34 insecticides/acaricides, 6 nematicides, 21 herbicides, and 1 herbicide safener. Most of them are safe to humans and environmentally friendly. The most developed fungicides are SDHI (succinate dehydrogenase inhibitors), DMI (demethylation inhibitors), QoI (quinone outside inhibitors), and QiI (quinone inside inhibitors). Due to the development of resistance to fungicides with existing modes of action, many fungicides possessing various novel modes of action have been launched or are under development. The trend of insecticide development is changing from organophosphorus, carbamate, and synthetic pyrethroids to nicotinic and diamide insecticides. During the past decade, compounds possessing a variety of novel modes of action have also been launched or are under development. Flupyradifurone and flupyrimin, exhibiting extremely low honeybee toxicity, have been developed and subjected to practical use. Herbicides possessing varied modes of action, such as acetolactate synthase, p-hydroxyphenylpyruvate dioxygenase, protoporphyrinogen oxidase, and very-long-chain fatty acid elongase inhibition, have been developed, but no herbicides possessing a novel mode action have commercialized in nearly 30 years. It is of interest that cyclopyrimorate, which was recently launched, and tetflupyrolimet, which is under development, have novel modes action: homogentisate solanesyltransferase (HST) and dihydroorotate dehydrogenase (DHODH) inhibition, respectively. The development of useful acaricides and nematicides is also progressing. Some natural product origin pesticides are getting attention.

No abstract

No abstract

Loss of /3-carotene was monitored from spectra over the range 350-520 nm of solutions of aliquots (about 100 mg) in light petroleum (10 mL). Pigment concentration was calculated from the absorbance at 450 nm assuming Elcm1% = 2500. Control experiments were carried on simultaneously by storing trays in the dark. Antioxidant effect of ethoxyquin (0.02%) was determined in methyl oleate solutions exposed to the light. LITERATURE CITED

Investigation on the Toxin Production by Several Blast Fungus Strains and Isolation of Tenuazonic Acid as a Novel Toxin

No abstract

The cleavage of the N-S bond in 2,3-dihydro-2,2-dimethyl-7-benzofuranyl (di-n-butylaminosulfenyl) (methyl)carbamate was examined in different buffer solutions (hydrolysis), in buffer solution containing sulfhydryl reagents (thiolysis) and on thin-layer chromatographic plates. In buffer solution and on thin-layer plates, N-S bond cleavage readily occurred to give carbofuran as a major product, with minor amounts of bis-carbofuran-N,N'-disulfide and -trisulfide. The hydrolysis reaction in buffer proceeded with first-order kinetics. Significant amounts of an unknown polar compound were obtained in buffer solution and on thin-layer plates. In the presence of excess cysteine and glutathione at pH 7.0, thiolytic N-S bond cleavage occurred with first-order kinetics to give carbofuran as the sole identifiable product. At pH 5.0, three minor products were obtained along with carbofuran.

A survey of the toxin production by several strains of blast fungus was carried out. Among the strains tested only one strain, C 1 (THU 69-03) produced a-picolinic acid with good yield and other strains produced neither a-picolinic acid nor piricularin. On the other hand, tenuazonic acid and its Fe-chelate compound were isolated as novel blast fungus toxins from the surface culture brothes of these strains, but they could not be isolated from the shaking culture brothes. The phytotoxic effect of tenuazonic acid on rice plants in regard to varietal difference was also studied.