RESUMO
The isobutyl amides pellitorine (compound 1) and 4,5-dihydropiperlonguminine (compound 2) were extracted from the seeds of Piper tuberculatum Jacq. (Piperaceae) in yields of 6.10 and 4.45% respectively. The acute toxicities to the velvetbean caterpillar, Anticarsia gemmatalis (Hübner) (Lepidoptera: Noctuidae), of extracts of seeds, leaves and stems of P. tuberculatum, and of compounds 1 and 2, were evaluated by means of contact bioassays. The extracts caused 80% mortality when doses higher than 800.00 microg insect(-1) of extract of seeds, leaves and stems were administered to the velvetbean caterpillars. Compounds 1 and 2 showed 100% mortality at doses of 200 and 700 microg insect(-1) respectively. The LD(50) and LD(90) values were respectively 31.3 and 104.5 microg insect(-1) for compound 1, and 122.3 and 381.0 microg insect(-1) for compound 2. The potential value of extracts and amides derived from P. tuberculatum as efficient insecticides against velvetbean caterpillars is discussed.
Assuntos
Ácidos Graxos Insaturados , Inseticidas , Mariposas , Piper/química , Alcamidas Poli-Insaturadas , Amidas/química , Amidas/isolamento & purificação , Animais , Benzodioxóis/química , Benzodioxóis/isolamento & purificação , Ácidos Graxos Insaturados/química , Ácidos Graxos Insaturados/isolamento & purificação , Controle de Insetos , Inseticidas/química , Inseticidas/isolamento & purificação , Extratos Vegetais/química , Alcamidas Poli-Insaturadas/química , Alcamidas Poli-Insaturadas/isolamento & purificação , Sementes/químicaRESUMO
A rapid, sensitive and reliable reverse-phase HPLC method was used for the quantitative determination of the anti-fungal and insecticide amides, dihydropiplartine (1), piplartine (2), deltaalpha,beta-dihydropiperine (3) and pellitorine (4) in plants in natura, in plantlets in vitro and ex vitro, and in callus of Piper tuberculatum. Well-resolved peaks were obtained with good detection response and linearity in the range of 15.0-3000 microg/mL. The plants in natura contained compounds 1-4, the plantlets ex vitro and in vitro accumulated compounds 1-2 and 1-4, respectively, while only amide 4 was found in callus.
Assuntos
Amidas/análise , Antifúngicos/análise , Inseticidas/análise , Piper/química , Piperidinas/análise , Piperidonas/análise , Cromatografia Líquida de Alta Pressão/métodos , Técnicas de Cultura , Ácidos Graxos Insaturados/análise , Estrutura Molecular , Piper/crescimento & desenvolvimento , Extratos Vegetais/química , Alcamidas Poli-Insaturadas , Análise EspectralRESUMO
In continuation of our study of the Piperaceae we have isolated several amides, mainly those bearing isobutyl, pyrrolidine, dihydropyridone and piperidine moieties. Bioactivity-guided fractionation of extracts from leaves of Piper arboreum yielded two new amides, N-[10-(13,14-methylenedioxyphenyl)-7(E),9(Z)-pentadienoyl]-pyrrolidine (1), arboreumine (2) together with the known compounds N-[10-(13,14-methylenedioxyphenyl)-7(E)-pentaenoyl]-pyrrolidine (3) and N-[10-(13,14-methylenedioxyphenyl)-7(E),9(E)-pentadienoyl]-pyrrolidine (4). Catalytic hydrogenation of 3 yielded the amide N-[10-(13,14-methylenedioxyphenyl)-pentanoyl]-pyrrolidine (5). We also have isolated six amides (6-11) and two antifungal cinnamoyl derivatives (12, 13) from seeds and leaves of Piper tuberculatum. Compounds 1-11 showed antifungal activity as determined by direct bioautography against Cladosporium sphaerospermum while compounds 3-4 and 6-13 also showed antifungal activity against C. cladosporioides.
