Organic compounds -- part of the class 532-570 series – Organic compounds – Heterocyclic carbon compounds containing a hetero ring...
Patent
1983-06-08
1989-02-07
Milestone, Norma S.
Organic compounds -- part of the class 532-570 series
Organic compounds
Heterocyclic carbon compounds containing a hetero ring...
C07D30930
Patent
active
048032891
DESCRIPTION:
BRIEF SUMMARY
This invention relates to compounds having activity as oviposition attractants for mosquitoes and to the use of these compounds in mosquito control.
The eggs of the mosquitoes Culex pipiens fatigans (=quinquefasciatus), Culex pipiens pipiens, Culex pipiens molestus and Culex tarsalis have previously been studied with a view to identification of the natural oviposition attractant which is present therein. The eggs have been found to contain a mixture of 1,3-diglycerides of mono- and di-acetoxy fatty acids and these glycerides have been identified as being responsible for the natural oviposition attractive effect of the eggs. These compounds are of interest in mosquito control in view of the involvement of mosquitoes of this genus in various parts of the world in the spread of various diseases, for example Culex pipiens fatigans acting as a vector for filarial disease (Wuchereria bancrofti) known as elephantiasis, Culex tarsalis for Western equine encephalitis, the Culex tritaeniorhynchus group for Japanese B encephalitis and other viral diseases, and the Culex pipiens group for Rift Valley fever.
We have now isolated from the apical droplets of eggs of Culex pipiens fatigans further, non-glyceride, oviposition attractants having a structure which is an unusual one among pheromones. These attractants, whose existence was previously quite unexpected, are present in the apical droplet of the eggs in only small amounts but they are significantly more potent as oviposition attractants for mosquitoes of this general type than the previously reported glyceride oviposition attractants. These newly discovered compounds, together with certain analogues thereof, are therefore of considerable interest for use in mosquito control.
Accordingly, the present invention comprises a compound of formula ##STR2## in which R represents hydrogen, formyl or an alkanoyl (alkyl-CO-) group of two to twenty-five carbon atoms and R' represents an alkyl group of one to thirty-five carbon atoms.
The major naturally occurring compound of this type is 6-acetoxy-5-hexadecanolide but we have also identified the compounds 6-hydroxy-5-hexadecanolide and 6-acetoxy-5-tetradecanolide as occurring in mosquito eggs. However, whilst compounds (I) in which R is hydrogen or especially an acetyl group are of particular interest, as are compounds (I) in which R' is n-octyl or particularly n-decyl, variations from the naturally occurring structures through the presence of a formyl group or of other branched or, more preferably, straight chain alkanoyl or alkyl groups, for example propionyl in the case of R and n-hexyl or n-dodecyl in the case of R', are also of interest. In particular, the presence of a smaller alkyl group R', for example of as few as six, four or even less carbon atoms, may be of value in some circumstances through the consequent increase in volatility of the compound (I). Similarly, the presence of an alkyl group R' larger than C.sub.8 -C.sub.10 or an alkanoyl group R larger than C.sub.2 may be of value in the preparation of long acting compositions through the consequent decrease in volatility. Such higher molecular weight compounds may also be advantageous through a consequent reduction in water solubility, although 6-acetoxy-5-hexadecanolide itself already has only a low water solubility. An increase in the molecular weight of the compound through an increase in the size of R' rather than of R is preferred in view of the lesser effect upon the oviposition attractant activity of the compound. Thus, a molecular weight of about 600 may conveniently be achieved through an increase in the size of R' by about twenty carbon atoms rather than of R or of both R and R' by about ten carbon atoms. Accordingly a preferred upper limit of size for an alkanoyl group comprising R is less than twenty-five or even twenty carbon atoms, an upper limit of ten carbon atoms or more especially only three, four or five carbon atoms being preferred, whilst an increase in the size of an alkyl group comprising R' not only to fourteen, sixteen or eighteen carbon
REFERENCES:
CA 80:95622t.
Crundwell et al., J. Med. Chem., 12, 1969, 547-548.
Fore et al., J. Amer. Oil Chem. Soc., 43, 1966, 581-584.
Laurence et al., J. Chem. Soc. Chem. Commun., No. 1, Jan. 1982, 59-60.
Iltis and Zweig, Annals of the Entomological Society of America, 1962, 55, 409-415.
Takata and Harwood, Annals of the Entomological Society of America, 1964, 57, 749-753.
Osgood, Journal of Economic Entomology, 1971, 64, 1038-1041.
Starratt and Osgood, Biochemica et Biophysica Acta, 1972, 280, 187-193.
Starratt and Osgood, Comp. Biochem. Physiol., 1973, 46B, 857-859.
Ikeshoji and Mulla, Jap. J. Sanit. Zool., 1974, 25, 89-94.
Ikeshoji, Saito & Yano, Appl. Ent. Zool., 1975, 10, 239-242.
Starratt, Chemistry and Physics of Lipids, 1976, 16, 215-218.
Ikeshoji et al., J. Pesticide Sci., 1979, 4, 187-194.
Bruno and Laurence, J. Med. Entomol., 1979, 16, 300-305.
Laurence Brian R.
Pickett John A.
Milestone Norma S.
National Research Development Corp.
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