Insecticidal constituents

We ve discussed only open-chain compounds up to this point, but most organic compounds contain rings of carbon atoms. Chcysanthemic acid, for instance, whose esters occur naturally as the active insecticidal constituents of chrysanthemum flowers, contains a three-membered (cyclopropane) ring. 

The edible parts of parsnips (Pastimea sativa L.), which have been consumed for centuries by humans without causing any obvious harm, were found to contain a chemical of insecticidal and strong synergistic nature (1). The insecticidal constituent, present at about 200 p.p.m., was isolated and identified as 5-allyl-l-methoxy-2, 3-methylenedioxybenzene or myristicin. Its toxicity to various insects [vinegar flies, houseflies, Mediterranean fruit flies, mosquito larvae, Mexican bean beetles, and pea aphids] was established and compared with pyrethrum and aldrin (Tables I and II). The knockdown effect, although definite, was not as great as that of pyrethrum. In tests... 

Sawicki and Elliott (31) re-examined the insecticidal activity of pyrethrin extracts and its four insecticidal constituents against four strains of houseflies, and checked the relative toxicity of pyrethrins I and II. This work confirmed the earlier results, showing that pyrethrin II was 1.3 to 1.6 times more toxic than pyrethrin I, but that the relative toxicities of pyrethrins I and II against the four strains of flies differed little. Resistance to knockdown but not to killing was associated in these strains with resistance to organophos-phorus and chlorinated insecticides. 

Asteraceae, Milliaceae and Apiaceae, are among some plant families that are known to have insecticidal constituents. Vulgar-one B (isolated from Artemisia douglasiana Asteraceae), apiol (isolated from Ligusticum hultenii Apiaceae), and cnicin (isolated from Centaurea maculosa Asteraceae) cause significant mortality to Formosan subterranean... 

Synonyms Pyrethrin I or II Cinerin I or II Jasmolin I or II. Note Pyrethrum flowers yield pyrethrum extract, of which the insecticidal constituents are collectively the pyrethrins or the natural pyrethrins ... 

Odoracin (141) is an insecticidal constituent of Daphne odora which contains an unusual deca-2,4-dienoate ortho-ester function. Gnidilatidin (142) and gnidi-... 

Pandji, C. et al.. Insecticidal constituents from four species of the Zingiberaceae, Phytochemistry, 34, 415, 1993. 

Two other important natural products are rotenone and ryanodine. Rotenone (101) (B-71MI10700) is the main insecticidal constituent of certain Derris and Lonchocarpus species, and derris dust is still available as an insecticide. It has been the subject of extensive structural and synthetic studies (B-72MI10704). Ryanodine (102) (B-7lMH070i) is extracted from the wood of Ryania speciosa and has been used in crude extract form as ryania. Despite its extreme complexity it has been totally synthesized (77PAC1329). 

Insecticide Rotenone. Principal insecticidal constituent of derris root. Toxic to humans at high dose-levels due to respiratory paralysis... 

Rotenone is the principal active insecticidal constituent of derris, the dried rhizome and roots of Derris elliptica, D. malaccensis (Leguminosae) and other species of Derris, and of lonchocarpus, the dried root of Lonchocarpus utilis, L. urucu and other species of Lonchocarpus (Leguminosae). 

About three years ago, our laboratory started a screening program for new insecticidal constituents from marine organisms especially from the Indo-Pacific locality [10]. Approximately 200 different extracts were tested for insecticidal activity against the polyphagous pest insect Spodoptera littoralis, a serious pest on important crops such as cotton and tomatoes [11, 12, 13]. The larvae of this pest insect are reared in the... 

JasmoltnS. Active insecticidal constituents of py-rethrum Bowers. Isoln and structure Godin ei at., J. Econ. EntomoL 58, 548 (1965) Godin et at., J. Chem. Soc. (C) 1966, 322. Stereochemistry Begley el aL, Chem. Commun. 1972, 1276. 

Pyrethrins, Active insecticidal constituents of pyrethrum flowers. Isoln Staudinger, Ruzicka, Heh. Chim. Acta 7, 177 (1924). Prepn by reconstitution from pyrethro-lone and chrysanthemic acid Elliott, Janes, Chem. A Ind. (London) 1969, 270. Structure CrOmbie et al. J. Chem. Soc. 1956, 3963 Godin et al, ibid. [Pg.1266]

In the mid-1960s investigations carried out independently by four research groups led to the isolation and subsequent structure elucidation from Amanita muscaria, A. strobiliformis, and A. pantherina of three fly-killing and narcosis potentiating compounds muscimol 37-40), ibotenic acid 40-44), and muscazone 43-47). At the same time tricholomic acid, another insecticidal constituent, was found in Tricholoma musca-rium 48,49). The nomenclature commonly accepted for these alkaloids was proposed by Eugster and Takemoto 50). 

Chrysanthemol from the leaves of Artemisia ludiviciana (Asteraceae) belongs to the cyclopropane monoterpenes Cinerins, jasmolins and pyrethrins (all including derivatives 1 and 11) are esters of /rara-chrysanthemic and pyrethric acid with terpenoid hydroxypentenones such as cinerolone, jasmolone and pyrethrolone. These are the active insecticidal constituents of pyrethrum recovered from dried flowers of several Chrysanthemum species (e.g. Chrysanthemum cinerariaefolium, Asteraceae). Some synthetic esters of chrysanthemic acid are also applied as insecticides. 

Insecticidal Constituents of Azadirachta indica and Melia azedarach (Meliaceae)... 

In this chapter, our recent studies on the Insecticidal constituents from these two plant species will be presented, concentrating first on the volatile organosulfur compounds recently Isolated from neem seeds (, and then on the azadirachtin-type tetranortrlterpenoid limonoids present In both species (22-26). Our recent studies on the Insecticidal mellaclns of the azadirachtin type suggest structure-activity relationships and a mode of action which may be useful In the design of synthetic analogs. 

Insecticidal Constituents of M. azedarach. Azadirachtin has previously been reported to be a constituent of both A. indica and M, azedarach (9.17.18.39.40). However, recent, more detailed investigations suggest that azadirachtin has never been isolated from or identified in authentic M azedarach. and that it has so far been shown to occur only in A indica (7.8.10.11.28.31). 

Miyakado, M., Nakayama, L, Ohno, N., and Yoshioka, H. 1983. Structure, Chemistry and Actions of the Piperaceae Amides New insecticidal Constituents Isolated from the Pepper Plant. In Natural Products for Innovative Pest Management, Whitehead, D. L., and Bowers, W. S., eds. Oxford, Pergamon Press, pp.369-384. 

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