Insecticidal properties

Phenazine-l-carboxamide (137) is known as oxychlororaphine and has been isolated from cultures of Pseudomonas chlororaphisit has some limited inhibitory properties, but the inhibitory action of phenazines is generally disappointing. Some phenazine derivatives have insecticidal properties thus, phenazine itself has been found to be toxic to the clothes moth, the Hawaiian beet webworm, the rice weevil and larva of the codling moth, but under trial conditions its toxicity to plant material, as evidenced by severe burning of foliage, was found to be too high to make it of practical value. 

Haloisoxazolylureas have acardicidal and insecticidal properties 76JAP(K)7659858 and isoxazoles with a phosphorothiolate functionality are broad spectrum insecticides <80USP4212861, 78USP4104375, 78JAP(K)7825566>. 

Diatomaceous Earth. .. then it couldn t have any significant insecticidal properties and would be labeled as something other than diatomaceous earth. http //froebuck.home.texas.net/toppage7.htm... 

With the present major emphasis on the preparation and testing of a seemingly endless number of synthetic organic compounds for pesticidal activity and the clamor over their possible adverse effects on public health and our general environment, comparatively few people realize that certain natural insecticides have been used by man for centuries. The ancient Romans apparently utilized false hellebore as a rodenticide and insecticide (13), and preparations of Tripterygium ivilfordii (thunder-god vine) and Derris species have been employed by the Chinese for hundreds of years as insecticides (16). The insecticidal properties of sabadilla (from Schoenocaulon species) were known in the sixteenth century tobacco was in use as... 

Despite the extensive screening of plants for insecticidal properties, only a vanishingly small proportion of the world s species have been examined. Apparently, even some very common kinds of plants have been overlooked Dr. Lichtenstein will discuss his research on natural insecticides in turnips, rutabaga, and other garden vegetables. 

HCH, sometimes misleadingly termed benzene hexachloride (BHC), exists in a number of different isomeric forms of which the gamma isomer has valuable insecticidal properties. These were discovered during the 1940s, and HCH came to be widely used as an insecticide to control crop pests and certain ectoparasites of farm animals after the Second World War. Crude technical BHC, a mixture of isomers, was the first form of HCH to be marketed. In time, it was largely replaced by a refined product called lindane, containing 99% or more of the insecticidal gamma isomer. 

Several coumarin derivatives have revealed pronounced medicinal value as antibacterial and antifungal agents [57,58]. Others have displayed antituber-cular activity [59] and some have insecticidal properties [60]. This prompted us to investigate the preparation of a new series of compounds containing coumarin moieties with different side chains or fused rings. 

Oxime carbamates are generally applied either directly to the tilled soil or sprayed on crops. One of the advantages of oxime carbamates is their short persistence on plants. They are readily degraded into their metabolites shortly after application. However, some of these metabolites have insecticidal properties even more potent than those of the parent compound. For example, the oxidative product of aldicarb is aldicarb sulfoxide, which is observed to be 10-20 times more active as a cholinesterase inhibitor than aldicarb. Other oxime carbamates (e.g., methomyl) have degradates which show no insecticidal activity, have low to negligible ecotoxicity and mammalian toxicity relative to the parent, and are normally nondetectable in crops. Therefore, the residue definition may include the parent oxime carbamate (e.g., methomyl) or parent and metabolites (e.g., aldicarb and its sulfoxide and sulfone metabolites). The tolerance or maximum residue limit (MRL) of pesticides on any food commodity is based on the highest residue concentration detected on mature crops at harvest or the LOQ of the method submitted for enforcement purposes if no detectable residues are found. For example, the tolerances of methomyl in US food commodities range from 0.1 to 6 mg kg for food items and up to 40 mg kg for feed items. ... 

PCP is commonly used as a wood preservative having both antifungal and insecticide properties. It has also been used in a range of areas for antifungal, antibacterial, general herbicide, and slime prevention in both industrial and consumer applications. Chronic exposure to PCP has effects on the liver, kidneys, and immune system. PCP also has the potential to cause reproductive problems and has been listed as a probable carcinogen. 

In the search for safe insecticides the authors have prepared hundreds of new products and subjected them to preliminary screening tests against insects. That part of their work dealing with methylenedioxyphenyl derivatives was prompted by the original fundamental studies of 0. F. Hedenburg, with whom they have collaborated in this field. Two materials of this type—piperonyl butoxide (I) and piperonyl cyclonene (II)—have recently been introduced commercially. These products have definite insecticidal properties in themselves, but show their maximum efficiency toward insects and other arthropods when used in combination with pyrethrins. Furthermore, they are at least as nontoxic... 

A striking illustration of the effect of chemical structure on insecticidal properties is provided by the data given in this paper on compounds related to piperonyl butoxide. According to the above theory, the methylenedioxyphenyl nucleus present in this substance is the toxophore. The materials selected for comparison show the reduction in toxicity produced, first, by modifying the toxophore, and, second, by substituting different groups for the auxotox radical. 

Trigard 75 WP is a new insecticide with a unique mode of action and a unique triazine structure. It is a solid formulated as a wettable powder and is packaged in water-soluble bags. The active ingredient in Trigard has the common name cyromazine. Cyromazine is a triazine, but, unlike the well-known triazine herbicides, this compound has insecticidal properties and no herbicidal activity. Cyromazine has low mammalian toxicity and low vapor pressure. It is hydrophilic, so dermal penetration is expected to be... 

In the family Fabaceae,8 CS2 production was investigated with 40 taxa of the subfamily Mimosoideae 29 produced CS2 and 18 produced COS (the latter was not formed in absence of CS2 production). CS2 production was less common in the subfamilies, Caesalpiniodeae and Papillonoideae. Since CS2 has a variety of bacteriostatic, fungicidal, nematicidal, and insecticidal properties, this production might deter soil pathogens. 

Kenaga, E.E. 1971. Some physical, chemical and insecticidal properties of some O-O-dialkyl 0-3,5,6-trichloro-2-pyridyl) phosphates and phosphorothioates. Bull. World Health Org. 44 225-228. 

The self-condensation of 3,4-dichlorothiophene 1,1-dioxide (89) in refiuxing xylene yields trace amounts of 2,3,7,8-tetrachlorodibenzo-thiophene 5,5-dioxide (90). The major product (50%) is the benzothio-phene (91) formed by loss of SO2 and HCl from the Diels-Alder dimer of 89. Further treatment of 91 with 89 in refiuxing trichlorobenzene again yields 90 (23%). Compound 90 is reported to possess insecticidal properties. ... 

Mention was made of the natural product pyrethrins and the structure of pyrethrin I was given in this chapter, Section 3.1. Because of the unique structures of these cyclopropane-containing natural products and their high insecticidal properties, syntheses of analogs have been studied. The isobutenyldimethylcyclopropanecarboxylic acid moiety, called chrysan-themic acid, has been modified by using different ester groups. As a result a number of synthetic pyrethroids are available for certain specific uses. 

The discovery in the early years of the 20 century that certain phosphate esters possess mammahan toxicity and insecticidal properties heightened interest in this class of compounds, both in agriculmre and as potential agents in chemical warfare. Parathion became the practical choice as a broad-spectrum insecticide because of its greater stability and lower mammalian toxicity compared to its P=0 analogue, paraoxon . 

---