title: Di- and tri-fluorinated analogs of methyl eugenol: attraction to and metabolism in the Oriental fruit fly, Bactrocera dorsalis (Hendel).
abstract: Oriental fruit fly, Bactrocera dorsalis (Hendel), males are attracted to the natural phenylpropanoid methyl eugenol (ME). They feed compulsively on ME and metabolize it to ring and side-chain hydroxylated compounds that have both pheromonal and allomonal properties. Previously, we demonstrated that mono-fluorination at the terminal carbon of the ME side-chain significantly reduced metabolic side-chain hydroxylation, while mono-fluorination of ME at position 4 of the aromatic ring blocked ring-hydroxylation but surprisingly enhanced side-chain hydroxylation. Here, we demonstrated that the introduction of fluorine atoms on both the ring and side-chain of ME blocks both positions that undergo enzymatic hydroxylation and, in particular, completely inhibits oxidative biotransformation of the allyl group. In laboratory experiments, B. dorsalis males initially were more attracted to both 1-fluoro-4,5-dimethoxy-2-(3,3-difluoro-2-propenyl)benzene (I) and 1-fluoro-4,5-dimethoxy-2-(3-fluoro-2-propenyl)benzene (II) than to ME. However, both I and II were taken up by flies at rates significantly less than that of ME. Flies fed with difluoroanalog II partially metabolized it to 5-fluoro-4-(3-fluoroprop-2-en-1-yl)-2-methoxyphenol (III), and flies fed with trifluoroanalog I produced 4-(3,3-difluoroprop-2-en-1-yl)-5-fluoro-2-methoxyphenol (V), but the rates of metabolism relative to rates of intakes were much lower compared to those of ME. Flies that consumed either the tri- or difluorinated analog showed higher post-feeding mortality than those that fed on methyl eugenol. In field trials, trifluoroanalog I was ∼90% less attractive to male B. dorsalis than ME, while difluoroanalog II was ∼50% less attractive. These results suggest that increasing fluorination can contribute to fly mortality, but the trade off with attractancy makes it unlikely that either a di or trifluorinated ME would be an improvement over ME for detection and/or eradication of this species.
authors: U.S. Pacific Basin Agricultural Research Center, Agricultural Research Service, United States Department of Agricultural, 64 Nowelo St., Hilo, HI 96720, USA.
authors: Eric B
authors: EB
authors: Jang
authors: Ashot
authors: A
authors: Khrimian
authors: Matthew S
authors: MS
authors: Siderhurst
references: J Chem Ecol. 1993 Dec;19(12):2935-46
references: 24248786
references: J Org Chem. 2001 Jul 27;66(15):4965-72
references: 11463244
references: J Econ Entomol. 2009 Jun;102(3):815-35
references: 19610395
references: J Chem Ecol. 2006 Nov;32(11):2429-41
references: 17082990
references: Mutat Res. 1982 Apr;101(2):127-40
references: 6808388
references: Food Chem Toxicol. 2002 Jul;40(7):851-70
references: 12065208
references: Proc Natl Acad Sci U S A. 1975 Jul;72(7):2501-5
references: 1058469
references: J Chem Ecol. 2002 Jun;28(6):1161-72
references: 12184394
references: J Chem Ecol. 2009 Feb;35(2):209-18
references: 19198948
references: Mutat Res. 1989 Dec;224(4):427-36
references: 2685589
references: Cancer Res. 1983 Mar;43(3):1124-34
references: 6825084
references: Proc Natl Acad Sci U S A. 1981 Jul;78(7):4007-10
references: 16593048
references: J Chem Ecol. 2006 Jul;32(7):1513-26
references: 16794866