First Symposium on Chemical-Biological Correlation, May 26-27, 1950 (1951) / Chapter Skim
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Effect of Structural Changes in Plant Insecticides and Related Synthetic Compounds on Their Toxicity to Insects
Effect of Structural Changes in Plant Insecticides and Related Synthetic Compounds on Their Toxicity to Insects
Pages 245-268
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From page 245... ...
EFFECT OF STRUCTURAL CHANGES IN PLANT INSECTICIDES AND RELATED SYNTHETIC COMPOUNDS ON THEIR TOXICITY TO INSECTS by H.L. Haller Bureau of Entomology and Plant Quarantine Agricultural Research Administration U.S.
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From page 246... ...
58,59 Structural formulas for the pyrethrins, the insecticidal constituents of pyrethrum, were first proposed in 1924, 80 buj not until 1946 were the detailed structures of these complicated esters established with certainty."" Nicotine, rotenone, and the pyrethrins all have complicated structural formulas, and a comparison of them reveals no common grouping of atoms to which insecticidal action might be ascribed. Numerous derivatives of each of these compounds and closely related products have been prepared and tested for insecticidal properties, but only a few are equal to the natural products.
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From page 247... ...
" The toxicity values were obtained from articles by several different authors and therefore represent order of magnitude of relative toxicity rather than precise comparisons. TABLE 1 RELATIVE TOXICITY OF NICOTINE AND ITS DERIVATIVES AND ANALOGS TO APHIS RUMICIS Compound Median lethal concentration Levo-nicotine 1 Dextro -nicotine 5 di- Nicotine 2 d_l- a -Nicotine 31 Levo-nornicotine 0.
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From page 248... ...
2, 3'-Dipyridyl 3, 2'-Pyridyl-piperidine 2, 3'-Dipiperidyl 2-n-Tolyl pyrrolidine Pyrrolidine Pyridine Piperidine 31 0.1 5 100 50 100 50 20 125 25 DERRIS AND CUBE Rote none and Rotenoids These compounds are the principal insecticidal constituents of a number of leguminous fish-poison plants, of which derris and cube are the most important commercially. In the roots of these two plants the rotenone content usually constitutes one-third to one-half of the total ether extractives, the remainder being rotenoids.
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From page 249... ...
^ The results obtained are summarized in Table 2. TABLE 2 RELATIVE TOXICITY OF ROTENONE AND SOME OF ITS DERIVATIVES TO GOLDFISH Compound Approximate Relative Toxicity Rotenone Isorotenone Dihydrorotenone Acetyl rotenone Acetyl dihydrorotenone Rotenolone Acetyl rotenolone Dihydrorotenolone Acetyl dihydrorotenolone 1 0.
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From page 250... ...
The results are as follows: TABLE 3 RELATIVE TOXICITY OF ROTENONE AND SOME ROTENOIDS TO GOLDFISH Compound Approximate Relative Toxicity Rotenone 1. 0 Deguelin 0.56 Tephrosin 0.23 Toxicarol 0.65 Rotenone and the rotenoids contain asymmetric carbon atoms and optically active isomers of all except deguelin have been isolated in crystalline form from the plant extracts.
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From page 251... ...
) Compound Approximate Relative Toxicity Test Insect and Reference Deguelin (inactive)
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From page 252... ...
Both the pyrethrins and the cinerins are high-boiling oils, and all four compounds are closely related in chemical structure. Pyrethrin I and cinerin I are esters of chrysanthemum monocarboxylic acid (VIII)
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From page 253... ...
The esters obtained from the optically inactive keto alcohols and the optically active acids did not differ in toxicity from the compounds with both components optically active". Also with cinerin I, in which the side chain of the keto alcohol has been shown to have a cis configuration, "' no difference in toxicity was noted when the sid*
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Thus there were ten compounds closely related to cinerin I available for comparison of
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From page 255... ...
TABLE 7 RELATIVE TOXICITY OF ANALOGS OF CINERIN I TO HOUSE FLIES No. Cyc lope ntenol one Side Chain Chrysanthemum Monocarboxylic Acid Relative Toxicity 1 -CH2CH = CHCH=CH2 (Pyrethrolone)
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From page 256... ...
Many other modifications can be made in the keto-alcohol portion of the molecule and such alcohols can then be esterified not only with chrysanthemum monocarboxylic acidt but with other substituted cyclopropanecarboxylic acids or with entirely different types of acids. Studies in which the acid component of pyrethrin I and cinerin I, chrysanthemum monocarboxylic acid (VIII)
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From page 257... ...
is appreciably more toxic than the pyrethrins to house flies. ^° Compounds XVI to XX all show the rapid paralytic or knockdown action characteristic of the pyrethrins.
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Each fraction was separately added to pyrethrum extract in refined kerosene and tested against house flies by the turntable method.
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From page 259... ...
. % in 10 in iD , % Sesame oil 0 2 Pyrethrins 99 21 Pyrethrins + sesame oil 100 57 Pyrethrins + fraction I 100 100 Pyrethrins + fraction II 100 91 Pyrethrins + fraction III 100 21 Pyrethrins + fraction IV 100 29 TABLE 9 EFFECTIVENESS AGAINST HOUSE FLIES OF FRACTIONS OF SESAME OIL, WITH AND WITHOUT PYRETHRUM, IN REFINED KEROSENE PLUS 10% OF ACETONE (2 tests with 150 flies each; concn.
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From page 260... ...
3 have studied the histological effects of pyrethrum and sesamin on the central nervous system and muscles of the house fly. Flies rendered moribund by pyrethrum showed clear spaces in the brain tissue and dissolution of the fiber tracts, and sesamin caused vacuolation around the large nerve cells.
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From page 261... ...
Technical piperonyl cyclonene obtained on condensation of alkyl-3, 4-methylene dioxystyryl ketones with ethyl acetoacetate^, ®? contains 80 per cent of a mixture of compounds XXIV and
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From page 262... ...
-.^ ^* H2C CH-COOC2H5 H2C C C H XXIV XXV Piperonyl butoxide^Z- 87 [s obtained as a technical product containing 80 per cent of XXVI.
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From page 263... ...
, Soap Sanit. Chemicals.
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From page 264... ...
Boyce Thompson Inst.
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From page 265... ...
, Contrib. Boyce Thompson Inst.
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From page 266... ...
266 88. Weed, A., Soap Sanit.
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From page 267... ...
I wonder if it could mean that the I -isomer is acting not only in a noncontributory manner, but is acting, shall we say, to protect the house fly, as it were, against the d-isomer. If that is the case, does it mean, then, that we have here a sort of p-aminobenzoic acid - sulfanilamide mutual antagonism between the two?
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From page 268... ...
If you write the molecule of histamine or anabasine in the ionic form, you cannot possibly construct such a chelated formula but, if you construct the alpha isomer of nicotine and anabasine then, particularly in the case of anabasine where there is no N-mcthyl group to introduce any steric factors, you have the possibility of constructing a chelated ring. I want to ask Dr.
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