Exploration of the DNA Photocleavage Activity of <i>O</i>-Halo-phenyl Carbamoyl Amidoximes: Studies of the UVA-Induced Effects on a Major Crop Pest, the Whitefly <i>Bemisia tabaci</i>
Anastasios Panagopoulos,
Konstantina Alipranti,
Kyriaki Mylona,
Polinikis Paisidis,
Stergios Rizos,
Alexandros E. Koumbis,
Emmanouil Roditakis,
Konstantina C. Fylaktakidou
Affiliations
Anastasios Panagopoulos
Laboratory of Organic, Bioorganic and Natural Product Chemistry, Molecular Biology and Genetics Department, Democritus University of Thrace, 68100 Alexandroupolis, Greece
Konstantina Alipranti
Department of Agriculture, School of Agricultural Sciences, Hellenic Mediterranean University, Gianni Kornarou, Estavromenos 1, 71410 Heraklion, Greece
Kyriaki Mylona
Department of Agriculture, School of Agricultural Sciences, Hellenic Mediterranean University, Gianni Kornarou, Estavromenos 1, 71410 Heraklion, Greece
Polinikis Paisidis
Laboratory of Organic Chemistry, Chemistry Department, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
Stergios Rizos
Laboratory of Organic Chemistry, Chemistry Department, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
Alexandros E. Koumbis
Laboratory of Organic Chemistry, Chemistry Department, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
Emmanouil Roditakis
Department of Agriculture, School of Agricultural Sciences, Hellenic Mediterranean University, Gianni Kornarou, Estavromenos 1, 71410 Heraklion, Greece
Konstantina C. Fylaktakidou
Laboratory of Organic, Bioorganic and Natural Product Chemistry, Molecular Biology and Genetics Department, Democritus University of Thrace, 68100 Alexandroupolis, Greece
The DNA photocleavage effect of halogenated O-carbamoyl derivatives of 4-MeO-benzamidoxime under UVB and UVA irradiation was studied in order to identify the nature, position, and number of halogens on the carbamoyl moiety that ensure photoactivity. F, Cl, and Br-phenyl carbamate esters (PCME) exhibited activity with the p-Cl-phenyl derivative to show excellent photocleavage against pBR322 plasmid DNA. m-Cl-PCME has diminished activity, whereas the presence of two halogen atoms reduced DNA photocleavage. The substitution on the benzamidoxime scaffold was irrelevant to the activity. The mechanism of action indicated function in the absence of oxygen, probably via radicals derived from the N-O bond homolysis of the carbamates and in air via hydroxyl radicals and partially singlet oxygen. The UVA-vis area of absorption of the nitro-benzamidoxime p-Cl-PCMEs allowed for the investigation of their potential efficacy as photopesticides under UVA irradiation against the whitefly Bemisia tabaci, a major pest of numerous crops. The m-nitro derivative exhibited a moderate specificity against the adult population. Nymphs were not affected. The compound was inactive in the dark. This result may allow for the development of lead compounds for the control of agricultural insect pests that can cause significant economic damage in crop production.
