scispace - formally typeset
Search or ask a question
Author

Isamu Nakayama

Bio: Isamu Nakayama is an academic researcher from Sumitomo Chemical. The author has contributed to research in topics: Piper & Fenvalerate. The author has an hindex of 3, co-authored 3 publications receiving 118 citations.

Papers
More filters
Journal ArticleDOI
TL;DR: The Piperaceae Amides I: Structure of Pipercide, A New Insecticidal Amide from Piper nigrum L. as discussed by the authors, Vol. 43, No. 7, pp. 1609-1611
Abstract: (1979). The Piperaceae Amides I: Structure of Pipercide, A New Insecticidal Amide from Piper nigrum L. Agricultural and Biological Chemistry: Vol. 43, No. 7, pp. 1609-1611.

80 citations

Journal ArticleDOI
TL;DR: In this article, the joint action of Pipercide and Co-occurring Compounds Isolated from Piper nigrum L. was investigated and the results showed that the compound is effective in killing insects.
Abstract: (1980). Insecticidal Joint Action of Pipercide and Co-occurring Compounds Isolated from Piper nigrum L. Agricultural and Biological Chemistry: Vol. 44, No. 7, pp. 1701-1703.

26 citations

Book ChapterDOI
TL;DR: In this paper, the relative toxicity of fenvalerate As (S-acid, R-alcohol) to Aα was enhanced in accordance with exposure period of mosquito larva on dipping or tobacco cutworm on dry leaf residue.
Abstract: A number of stereoisomers of recent pyrethroids having an α-cyano-3-phenoxybenzyl moiety, i.e., fenvalerate, Cypermethrin and fenpropanate could be optionally synthesized from (+)- or (-)-3-phenoxy-mandelic acid and their absolute configurations were determined to be S to the benzylic asymmetric carbon atoms of the most active isomers. Toxicity ratios of the S-isomers to the R-isomers to house fly were generally larger than those to mosquito larva. Relative toxicity of fenvalerate As (S-acid, R-alcohol) to Aα was enhanced in accordance with exposure period of mosquito larva on dipping or tobacco cutworm on dry leaf residue. The late emerging toxicity of the As appears to result from in vivo activation as evidenced by biological assays involving hemolymph exchange and ligature on larvae of cabbage armyworm. Feeding deterrent nature of As was also discussed.

18 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: In recent years, the use of essential oils (EOs) derived from aromatic plants as low-risk insecticides has increased considerably owing to their popularity with organic growers and environmentally conscious consumers.
Abstract: In recent years, the use of essential oils (EOs) derived from aromatic plants as low-risk insecticides has increased considerably owing to their popularity with organic growers and environmentally conscious consumers. EOs are easily produced by steam distillation of plant material and contain many volatile, low-molecular-weight terpenes and phenolics. The major plant families from which EOs are extracted include Myrtaceae, Lauraceae, Lamiaceae, and Asteraceae. EOs have repellent, insecticidal, and growth-reducing effects on a variety of insects. They have been used effectively to control preharvest and postharvest phytophagous insects and as insect repellents for biting flies and for home and garden insects. The compounds exert their activities on insects through neurotoxic effects involving several mechanisms, notably through GABA, octopamine synapses, and the inhibition of acetylcholinesterase. With a few exceptions, their mammalian toxicity is low and environmental persistence is short. Registration has been the main bottleneck in putting new products on the market, but more EOs have been approved for use in the United States than elsewhere owing to reduced-risk processes for these materials.

859 citations

Journal ArticleDOI
TL;DR: The secondary metabolites isolated from Piper species for the period 1907 to June 1996 have been reviewed in this paper, where nearly six hundred chemical constituents belonging to different classes of bioactive compounds are listed together with their source(s) and references.

849 citations

Book ChapterDOI
TL;DR: Physical properties that influence the environmental disposition and subsequently affect bioavailability of the compounds in water, soil, air, produce, and nontarget species are also instrumental in determining the impact of current and future synthetic pyrethroid insecticides.
Abstract: Synthetic pyrethroid insecticides are photostable analogs of the natural pyrethrins of botanical origin. Their structures range from very similar to the original (e.g., allethrin, Fig. 1) to highly dissimilar compounds (e.g., flucythrinate, Fig. 1). Directed synthesis by groups in Japan (Sumitomo Chemical Co.) and England (NRDC) resulted in very potent insecticides and a commercial success for the synthetic pyrethroids.

339 citations

Journal ArticleDOI
TL;DR: The conclusions of the current work with Piperaceae are that Piper extracts offer a unique and useful source of biopesticide material for controlling small-scale insect out-breaks and reducing the likelihood of resistance development when applied as a synergist with other botanical insecticides such as pyrethrum.
Abstract: The tropical plant family Piperaceae has provided many past and present civilizations with a source of diverse medicines and food grade spice. The secondary plant compounds that produce these desired qualities function also as chemical defenses for many species in the genus Piper. The compounds with the greatest insecticidal activity are the piperamides. Many studies have shown the effectiveness of Piper spp. extracts for the control of stored products pests and recently studies from our laboratory group have tested the extracts of Piper. nigrum, P. guineense and P. tuberculatum against insect pests of the home and garden. These results and those from investigations that examined the biochemical and molecular modes of action of the piperamides singly or in combination will be the focus of this review. The conclusions of our current work with Piperaceae are that Piper extracts offer a unique and useful source of biopesticide material for controlling small-scale insect out-breaks and reducing the likelihood of resistance development when applied as a synergist with other botanical insecticides such as pyrethrum.

236 citations

Journal ArticleDOI
TL;DR: The authors' present society can afford to discuss long-term health implications of agents used to control insect pests, and many new and difficult questions have emerged about health and environmental health, giving rise to a distinct area of study called risk assessment.
Abstract: For centuries humans have used natural insecticides to combat insect pests that compete for our food and fiber or that affect public health. Some of these compounds were plant extracts or plant parts, others were mined from the earth. In the twentieth century synthetic insecticides have replaced natural ones as the standard means of controlling detrimental insects, ticks, and mites. Although early natural insecticides such as arsenicals and nicotine carried with them acknowledged risks, a populace that often faced hunger and vector-borne diseases was willing to tolerate a degree of risk to realize the benefits of the chemicals being used. Synthetic insecticides brought a new order of insect control, but also a new collage of risks. As people became more comfortable in the developed areas of the world, threats of starvation, arthropod-vectored diseases, or loss of clothing and shelter often became minor concerns. The quality of our food supply and the economics of production now govern the majority of pest and pesticide approaches, products, and methodologies. At the same time, new questions have arisen regarding environmental quality, especially contamination of water, air, and soil by a host of chemicals, some of which are pesticides ' or their degradation products. Our present society can afford to discuss long-term health implications of agents used to control insect pests. Many new and difficult questions have emerged about health and environmental nsks, giving rise to a distinct area of study called risk assessment. One of the most challenging questions

190 citations