Isobutyl amides--potent compounds for controlling Diatraea saccharalis.
BACKGROUND
A dichloromethane-methanol extract of the seeds of Piper tuberculatum Jacq. (Piperaceae) and two isobutyl amides, 4,5-dihydropiperlonguminine (1) and pellitorine (2), which were isolated by chromatographic methods, were assayed for their lethality against the sugarcane borer Diatraea saccharalis F. (Lepidoptera: Pyralidae).


RESULTS
Bioassays were carried out with fourth-instar caterpillars through topical application of test solutions to the dorsal surface of the prothorax, and dose-response correlations were determined. Significant insect mortalities were observed 24, 48 and 72 h after treatment at concentrations of >or= 100 microg insect(-1). The LD(50) and LD(90) values for compound 1 were 92.83 and 176.50 microg insect(-1), and for compound 2 they were 91.19 and 184.56 microg insect(-1).


CONCLUSIONS
According to the LD(50) and LD(90) for compounds 1 and 2, it can be inferred that the values reflect an acute lethal response to both compounds, based on interaction(s) of the toxicants with a primary target or series of targets. Thus, the amides were demonstrated to have potential value in the control of the sugarcane borer.
Debonsi
Hosana M
HM
Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil. hosana@fcfrp.usp.br
Miranda
José E
JE
Murata
Afonso T
AT
de Bortoli
Sérgio A
SA
Kato
Massuo J
MJ
Bolzani
Vanderlan S
VS
Furlan
Maysa
M
D000577:Amides / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D052117:Benzodioxoles / Q000737:chemistry / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005231:Fatty Acids, Unsaturated / Q000737:chemistry / Q000494:pharmacology*; D007306:Insecticides / Q000737:chemistry / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects; D007928:Lethal Dose 50; D015394:Molecular Structure; D009036:Moths / Q000187:drug effects*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D053284:Polyunsaturated Alkamides / Q000737:chemistry / Q000494:pharmacology*; D012639:Seeds / Q000737:chemistry; D013997:Time Factors
C521746:4,5-dihydropiperlonguminine; D000577:Amides; D052117:Benzodioxoles; D005231:Fatty Acids, Unsaturated; D007306:Insecticides; D010936:Plant Extracts; D053284:Polyunsaturated Alkamides; C008778:pellitorine