RESUMO
The development of repellents as alternatives to insecticides has expanded in recent years. However, their use in isopod pest control is limited. To develop an isopod repellent, a plant extract library from wild plants native to the Kochi Prefecture was screened for repellent activity against pillbugs, and 82 samples (87%) exhibited repellent activity. Among them, (E)-7-phenyl-2-heptene-4,6-diyn-1-ol was isolated and identified as a repellent from the root of Bidens pilosa. It had a half-maximal effective concentration of 0.20 µm, with a strong repellency. A study of the structure-activity relationship to (E)-7-phenyl-2-heptene-4,6-diyn-1-ol revealed that the presence of a hydroxyl group and an aromatic at both ends of the length of the seven-carbon chain is important for the expression of repellency. These results can potentially lead to a new repellent of phenylalkyl alcohol.
Assuntos
Bidens , Isópodes , Animais , Extratos Vegetais/farmacologiaRESUMO
Luteolin, an abundant flavonoid in the leaves of Capsicum annuum, has antioxidant activity and is, thus, a key chemical for promoting plant residue utilization, especially for the development of healthcare products. We assessed the inhibitory effect of luteolin and its glycosides on osteoclastic differentiation in human cells and found that the differentiation was effectively inhibited at noncytotoxic concentrations. We also screened 47 varieties of C. annuum for the accumulation of luteolin and apigenin to determine the prevalence of luteolin in diverse cultivars and identify varieties with high and/or selective luteolin production. The glycosides of luteolin and apigenin were found in all the tested varieties, with luteolin predominant over apigenin in most varieties. The identification and characterization of highly productive varieties of C. annuum is expected to be beneficial for the effective development of useful luteolin-based products from plant residues.
Assuntos
CapsicumRESUMO
The use of biopesticides has expanded rapidly in recent years; however, their use in weed control is less advanced. Herein, we describe the development of a weed control agent by screening 208 plant extracts (104 species) for their plant growth-inhibition activities, which resulted in 142 active samples (from 89 plant species). Verbascoside, isolated from the shoots of Verbena incompta, was identified as a growth inhibitor against rice root (EC50, 1.75 m m), and its root growth-inhibition activity was also confirmed in radish, tomato, and Lotus japonicus. Verbascoside is composed of hydroxytyrosol (EC50,12.51 m m) and caffeic acid (EC50, 4.08 m m), 2 poorly water-soluble phenolic components with weak growth-inhibition activities, and 2 sugars, which are more soluble but inactive. The plant apparently developed a more active and highly soluble compound by condensing these 4 components. We conclude that a biopesticide containing verbascoside may be useful for weed-control purposes.
Assuntos
Glucosídeos/farmacologia , Herbicidas/farmacologia , Fenóis/farmacologia , Raízes de Plantas/efeitos dos fármacos , Verbena/química , Glucosídeos/química , Glucosídeos/isolamento & purificação , Herbicidas/isolamento & purificação , Fenóis/química , Fenóis/isolamento & purificação , Raízes de Plantas/crescimento & desenvolvimento , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/crescimento & desenvolvimento , Análise Espectral/métodosRESUMO
Plant defense responses are activated by various exogenous stimuli. We found that an aqueous extract of spent mushroom substrate used for the cultivation of Hypsizygus marmoreus induced defense responses in rice. Fractionation of the spent mushroom substrate extract indicated that the compounds responsible for this induction were neutral and hydrophilic molecules with molecular weights lower than 3 kDa. Compounds with these characteristics, namely glucose, fructose, and sucrose, were detected in the extract at concentrations of 17.4, 3.3, and 1.6 mM, respectively, and the treatment of rice leaves with these sugars induced defense responses. Furthermore, microarray analysis indicated that the genes involved in defense responses were commonly activated by the treatment of leaves with spent mushroom substrate extract and glucose. These findings indicate that the induction of defense responses by treatment with spent mushroom substrate extract is, at least in part, attributable to the sugar constituents of the extract.
Assuntos
Agaricales/efeitos dos fármacos , Oryza/fisiologia , Açúcares/farmacologia , Agaricales/química , Genes de Plantas , Peso Molecular , Oryza/genética , Água/químicaRESUMO
Although sweet pea (Lathyrus odoratus) beans contain toxic ß-aminopropionitrile, the plant itself is readily attacked by insects and is, therefore, protected through the use of pesticides. Consequently, the induction of L. odoratus resistance to insect attack via exogenous treatment is promising for pest control development. Screening of inducible elicitor effects showed that treatment of sweet pea foliage with jasmonic acid (JA) can induce antifeeding-based resistance to tobacco cutworm (Spodoptera litura) larvae. Spectroscopic analysis identified 2-cyanoethyl-isoxazolin-5-one (2-CEIX) as the antifeedant with a half-maximal effective concentration of 33.6 µmol/g fr. wt., i.e., exogenous JA treatment induced antifeeding activity due to the accumulation of 2-CEIX. Moreover, 2-CEIX-induced mortality of S. litura larvae was evaluated by a dipping test and the half-maximal lethal dose was determined to be 5.9 mg/mL. Therefore, 2-CEIX was concluded to be a suitable induced resistance target for elicitors or a lead compound for insecticide development.
Assuntos
Proteção de Cultivos/métodos , Ciclopentanos/farmacologia , Comportamento Alimentar/efeitos dos fármacos , Controle de Insetos/métodos , Inseticidas/farmacologia , Isoxazóis/farmacologia , Oxilipinas/farmacologia , Pisum sativum/efeitos dos fármacos , Extratos Vegetais/farmacologia , Spodoptera/fisiologia , Animais , Isoxazóis/metabolismo , Larva/fisiologia , Pisum sativum/química , Pisum sativum/metabolismo , Folhas de Planta/química , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismoRESUMO
The inducible metabolites were analyzed in barley leaves inoculated with Bipolaris sorokiniana, the causal agent of spot blotch of barley. HPLC analysis revealed that B. sorokiniana-infected leaves accumulated 4 hydrophilic compounds. They were purified by ODS column chromatography and preparative HPLC. Spectroscopic analyses revealed that they were tyramine (1), 3-(2-aminoethyl)-3-hydroxyindolin-2-one (2), serotonin (3), and 5,5'-dihydroxy-2,4'-bitryptamine (4). Among these, 2 and 4 have not been reported as natural products. They showed antifungal activity in an assay of inhibition of B. sorokiniana conidia germination, suggesting that they play a role in the chemical defense of barley as phytoalexins. The accumulation of 1-4 was examined also in the leaves of rice and foxtail millet. Rice leaves accumulated 2, 3, and 4, whereas foxtail millet leaves accumulated 3 and 4 in response to pathogen attack, suggesting the generality of accumulation of 3 and 4 in the Poaceae species.
Assuntos
Antifúngicos/imunologia , Hordeum/imunologia , Doenças das Plantas/imunologia , Saccharomycetales/efeitos dos fármacos , Sesquiterpenos/imunologia , Esporos Fúngicos/efeitos dos fármacos , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Cromatografia Líquida de Alta Pressão , Hordeum/metabolismo , Hordeum/microbiologia , Interações Hidrofóbicas e Hidrofílicas , Indóis/imunologia , Indóis/metabolismo , Indóis/farmacologia , Oryza/imunologia , Oryza/metabolismo , Oryza/microbiologia , Doenças das Plantas/microbiologia , Imunidade Vegetal , Folhas de Planta/imunologia , Folhas de Planta/metabolismo , Folhas de Planta/microbiologia , Saccharomycetales/patogenicidade , Saccharomycetales/fisiologia , Serotonina/biossíntese , Serotonina/imunologia , Serotonina/farmacologia , Sesquiterpenos/metabolismo , Sesquiterpenos/farmacologia , Setaria (Planta)/imunologia , Setaria (Planta)/metabolismo , Setaria (Planta)/microbiologia , Especificidade da Espécie , Esporos Fúngicos/patogenicidade , Esporos Fúngicos/fisiologia , Triptaminas/biossíntese , Triptaminas/imunologia , Triptaminas/farmacologia , Tiramina/biossíntese , Tiramina/imunologia , Tiramina/farmacologia , FitoalexinasRESUMO
The Poaceae is a large taxonomic group consisting of approximately 12,000 species and is classified into 12 subfamilies. Gramine and benzoxazinones (Bxs), which are biosynthesized from the tryptophan pathway, are well-known defensive secondary metabolites in the Poaceae. We analyzed the presence or absence of garamine and Bxs in 64 species in the Poaceae by LC-MS/MS. We found that Hordeum brachyantherum and Hakonechloa macra accumulated gramine, but the presence of gramine was limited to small groups of species. We also detected Bxs in four species in the Pooideae and six species in the Panicoideae. In particular, four species in the Paniceae tribe in Panicoideae accumulaed Bxs, indicating that this tribe is a center of the Bx distribution. Bxs were absent in the subfamilies other than Pooideae and Panicoideae. These findings provide an overview of biased distribution of gramine and Bxs in Poaceae species.
Assuntos
Alcaloides/metabolismo , Benzoxazinas/metabolismo , Poaceae/metabolismo , Triptofano/metabolismo , Alcaloides/análise , Benzoxazinas/análise , Cromatografia Líquida/métodos , Alcaloides Indólicos , Redes e Vias Metabólicas , Metabolismo Secundário , Espectrometria de Massas em Tandem/métodos , ortoaminobenzoatos/análise , ortoaminobenzoatos/metabolismoRESUMO
To elucidate the probing stimulants in rice plants for the white-backed planthopper, Sogatella furcifera, bioassay-guided separations were conducted, which led to the isolation of four active compounds. Using NMR and LC-MS spectra, their structures were determined as isoorientin 2â³-O-(6â´-(E)-feruloyl)glucoside, isoorientin 2â³-O-(6â´-(E)-p-coumaroyl)glucoside, tricin 5-O-glucoside, and isoscoparin 2â³-O-(6â´-(E)-feruloyl)glucoside.
Assuntos
Bioensaio , Hemípteros/efeitos dos fármacos , Oryza/química , Animais , Glucosídeos/química , Glucosídeos/farmacologiaRESUMO
The feeding response of larvae of the swallowtail butterfly, Graphium sarpedon nipponum (Lepidoptera: Papilionidae), is elicited by a methanolic extract from camphor tree (Cinnamomum camphora) leaves. Based on bioassay-guided fractionation, three compounds, isolated from the methanolic extract of fresh leaves of the camphor tree, were revealed to be involved in a multi-component system of feeding stimulants. Structures of these feeding stimulants were identified as sucrose, 5-O-caffeoylquinic acid and quercetin 3-O-ß-glucopyranoside by NMR and LC-MS.
Assuntos
Estimulantes do Apetite/farmacologia , Cinnamomum camphora/química , Comportamento Alimentar/efeitos dos fármacos , Larva/efeitos dos fármacos , Lepidópteros/fisiologia , Extratos Vegetais/farmacologia , Animais , Cromatografia Líquida de Alta Pressão , Larva/fisiologia , Lepidópteros/crescimento & desenvolvimento , Espectroscopia de Ressonância Magnética , Espectrofotometria UltravioletaRESUMO
Certain Japonica rice plant varieties (Oryza sativa L.) show resistance to the eggs of the white backed planthopper (Sogatella furcifera Horváth) by the formation of watery lesions and production of benzyl benzoate, an active ovicidal compound. Benzyl benzoate results in high ovicidal activity of S. furcifera eggs and reduces egg hatchability. The production of benzyl benzoate by the rice plants is only induced by an unknown elicitor(s) from the female S. furcifera. Therefore, we tried to isolate and identify these elicitors. An active 80% MeOH extract of S. furcifera was separated on a reverse-phase ODS MPLC, and the elicitor(s) was eluted in 100% MeOH and 100% EtOH fractions. Further separation of the active 100% MeOH fraction using a HPLC led to the isolation of four active compounds. The structures of each compound were determined by using NMR, LC-MS, and GC-MS spectra. The compounds were 1,2-dilinoleoyl-sn-glycero-3-phosphocholine, 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine, 1-palmitoyl-2-oleoyl-X-glycero-3-phosphoethanolamine, and 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine.
Assuntos
Aminas/química , Aminas/farmacologia , Hemípteros/química , Oryza/metabolismo , Óvulo/efeitos dos fármacos , Extratos Vegetais/biossíntese , Extratos Vegetais/farmacologia , Animais , Feminino , Hemípteros/efeitos dos fármacos , Hemípteros/fisiologia , Oryza/efeitos dos fármacos , Oviposição/efeitos dos fármacos , Óvulo/fisiologiaRESUMO
We elucidate the mechanism for inducing the production of ovicidal benzyl benzoate by Japonica rice varieties to kill eggs of the whitebacked planthopper, Sogatella furcifera (Horváth), lying in the rice plant. Even when subjected to physical damage by a needle or damage with water, the rice plant produced no benzyl benzoate. However, significant benzyl benzoate was produced when the plant was damaged with a methanol extract or homogenate of S. furcifera. The extract of the male did not induce the production of benzyl benzoate, but that of the female did. We concluded from these results that benzyl benzoate was induced by some elicitor(s) in the female of S. furcifera.
Assuntos
Benzoatos/metabolismo , Hemípteros/química , Oryza/metabolismo , Óvulo/efeitos dos fármacos , Animais , Benzoatos/química , Benzoatos/toxicidade , Feminino , Hemípteros/efeitos dos fármacos , Hemípteros/patogenicidade , Masculino , Oryza/parasitologia , Óvulo/parasitologia , Reprodução/efeitos dos fármacosRESUMO
The objective of this study was to establish a high quality progeny production system for the house fly parasitoid, Spalangia endius (Hymenoptera: Pteromalidae), by stockpiling hosts. We performed two host killing methods before host storage: (i) heat-killed by 30 min exposure to 50°C or (ii) freeze-killed by 10 min exposure to -80°C. The average number of parasitoids that emerged from nonstored house fly pupae after heat- or freeze-killing was not significantly different from live pupae. When house fly pupae stored at -20°C after heat-killing were supplied to S. endius, progeny production was significantly less than live pupae. Moreover, productivity became very low when house fly pupae refrigerated at 3°C after heat- or freeze-killing were supplied to S. endius. On the other hand, when house fly pupae stored at -80°C for 1 year after heat-killing were supplied to S. endius, the average number of parasitoids that emerged was not significantly different from live pupae. The average number of parasitoids that emerged from freeze-killed hosts kept for more than 8 weeks at -80°C was significantly fewer than live pupae. Thus, this study clarified that a higher-quality host can be maintained not only by simply storing at -80°C but also by adding heat treatment before storage.
Assuntos
Congelamento , Temperatura Alta , Moscas Domésticas/parasitologia , Himenópteros/patogenicidade , Animais , Agentes de Controle Biológico , Moscas Domésticas/crescimento & desenvolvimento , Himenópteros/crescimento & desenvolvimento , Controle Biológico de Vetores/métodos , Pupa/parasitologia , Fatores de TempoRESUMO
Changes in specialized metabolites were analyzed in barley (Hordeum vulgare) leaves treated with CuCl2 solution as an elicitor. LC-MS analysis of the CuCl2-treated leaves showed the induced accumulation of three compounds. Among them, two were purified by silica gel and ODS column chromatography and preparative HPLC and were identified as 2',3,4,4',6'-pentamethoxychalcone and 2'-hydroxy-3,4,4',6'-tetramethoxychalcone by spectroscopic analyses. The remaining compound was determined as 12-oxo-phytodienoic acid (OPDA), a major oxylipin in plants, by comparing its spectrum and retention time from LC-MS/MS analysis with those of the authentic compound. The accumulation of these compounds was reproduced in leaves inoculated with Bipolaris sorokiniana, the causal agent of spot blotch of the Poaceae species. This inoculation increased the amounts of other oxylipins, including jasmonic acid (JA), JA-Ile, 9-oxooctadeca-10,12-dienoic acid (9-KODE), and 13-oxooctadeca-9,11-dienoic acid (13-KODE). The treatments of the barley leaves with JA and OPDA induced the accumulation of methoxylchalcones, but treatment with 9-KODE did not. These methoxylchalcones inhibited conidial germination of B. sorokiniana and Fusarium graminearum, thereby indicating that these compounds possessed antifungal activity. Consequently, they are considered to be involved in the chemical defense processes as phytoalexins in barley. Accumulation of methoxylchalcones in response to JA treatment was observed in all seven barley cultivars tested, but was not detected in other wild Hordeum species, wheat, and rice, thus indicating that their production was specific to cultivated barley.
Assuntos
Hordeum , Cromatografia Líquida , Ciclopentanos , Fusarium , Oxilipinas/farmacologia , Folhas de Planta , Espectrometria de Massas em TandemRESUMO
Floral scent has been shown to elicit behavioral responses by butterflies which forage for flowers after receiving appropriate signals. In comparison with investigations about the role of floral scent, those of foliar odor are, however, very few. In this study, the foliar volatiles of Cinnamomum camphora (Lauraceae), which had been collected by air entrainment, exhibited activities toward Graphium sarpedon nipponum (Papilionidae) in both electrophysiological and behavioral tests. The volatiles were analyzed by capillary gas chromatography with electro-antennographic detection (GC-EAD). Two electrophysiological active compounds were found which were determined as nonanal and decanal by using gas chromatography-mass spectrometry (GC-MS). Female butterflies generally tend to show a greater EAG response than males to the headspace volatiles and EAG-active aldehydes. Two EAG-active aldehydes were found in attractant tests to be attractive to both sexes of the butterfly when treated individually. Although the difference between the sexes was not significant, the female butterflies' preference tended to be more active than that of the males.
Assuntos
Comportamento Animal/efeitos dos fármacos , Cinnamomum camphora/química , Lepidópteros/efeitos dos fármacos , Compostos Orgânicos Voláteis/farmacologia , Animais , Bioensaio , Cromatografia Gasosa , Fenômenos Eletrofisiológicos , Feminino , Lepidópteros/fisiologia , MasculinoRESUMO
The acceptance of camphor tree (Cinnamomum camphora) as a host plant for the larvae of common bluebottle (Graphium sarpedon nipponum) was explained by the presence of feeding stimulants in the leaves. When the active methanol extract of C. camphora leaves was separated into hexane and water layers, both layers showed high feeding activities for the larvae of G. sarpedon nipponum. Bioassay-guided fractionation of the hexane layer resulted in the isolation of a highly active compound, which was identified as a-linolenic acid by nuclear magnetic resonance spectrometry and gas chromatography-mass spectrometry.
Assuntos
Estimulantes do Apetite/farmacologia , Apetite/fisiologia , Cinnamomum camphora/química , Lepidópteros/efeitos dos fármacos , Extratos Vegetais/farmacologia , Folhas de Planta/química , Ração Animal , Animais , Apetite/efeitos dos fármacos , Estimulantes do Apetite/isolamento & purificação , Ovos , Comportamento Alimentar/efeitos dos fármacos , Comportamento Alimentar/fisiologia , Feminino , Hexanos , Larva/efeitos dos fármacos , Larva/fisiologia , Extratos Vegetais/análise , Água , Ácido alfa-Linolênico/isolamento & purificação , Ácido alfa-Linolênico/farmacologia , Ácido gama-Linolênico/isolamento & purificação , Ácido gama-Linolênico/farmacologiaRESUMO
We investigated the effect of treatment with hot water extracts from the spent mushroom substrates (SMSs) of Lentinula edodes and Hypsizygus marmoreus on the resistance of rice leaves to Pyricularia oryzae infection. The spraying of the SMS extracts clearly suppressed the development of lesions caused by Py. oryzae infection. The accumulation of phytoalexins momilactones A and B, oryzalexin A, and sakuranetin was markedly induced by the spraying of extracts. The enhanced expression of defense related genes PR1b and PBZ was also found in leaves sprayed with the extracts. Treatments with the extracts also affected phytohormone levels. The levels of N 6-(Δ2-isopentenyl)adenine and trans-zeatin markedly increased in response to treatment, whereas the levels of salicylic and jasmonic acids were largely unchanged.
RESUMO
Eight compounds isolated from Indian barnyard millet have been identified as L-malic acid, trans-aconitic acid, (+)-isocitric acid, 5-O-caffeoylquinic acid, 4-O-caffeoylquinic acid, isocarlinoside, 2"-O-rhamnosylisoorientin, and 7-O-(2"-O-glucuronosyl)glucuronosyltricin, respectively. These compounds showed high antifeeding activity against brown planthopper only when they were combined.
Assuntos
Echinochloa/química , Hemípteros/efeitos dos fármacos , Praguicidas/toxicidade , Animais , Hidrólise , Isocitratos/isolamento & purificação , Isocitratos/toxicidade , Cinética , Larva/efeitos dos fármacos , Malatos/isolamento & purificação , Malatos/toxicidade , Praguicidas/isolamento & purificação , Folhas de Planta , Caules de Planta , Ácido Quínico/isolamento & purificação , Ácido Quínico/toxicidadeRESUMO
The inducible metabolites in rice leaves treated with 1 mM jasmonic acid (JA) were analyzed using HPLC. We detected an increase in the levels of two compounds, 1 and 2. Based on the comparison with mass spectra and chromatographic behavior with authentic compounds, 1 and 2 were identified as 13-oxooctadeca-9,11-dienoic acid (13-KODE) and 9-oxooctadeca-10,12-dienoic acid (9-KODE), respectively, which have not been detected in rice to date. The accumulation of these compounds was also induced by an infection by Bipolaris oryzae. Treatment of rice leaves with KODEs induced the accumulation of defensive secondary metabolites, sakuranetin, naringenin, and serotonin, suggesting that KODEs may play a role in the elicitation of defense responses. The compounds that have an α, ß-unsaturated carbonyl group similar to KODEs did not reproduce the response of accumulation of defensive secondary metabolites, suggesting that additional structural factors such as long hydrophobic carbon chain are needed to elicit defense responses.
RESUMO
A new cucurbitane glucoside, 23-O-beta-D-glucopyranosyl-7-hydroxy-3-O-malonylcucurbita-5,24-dien-19-al, named momordicine V, has been isolated from Momordica charantia leaves, along with the previously reported compounds, momordicines I, II, IV and 3-O-malonylmomordicine I. The structure of the new compound was established on the basis of spectral analysis, as well as by its conversion to momordicine II by alkaline catalyzed hydrolysis. Momordicine V deterred significantly the oviposition by L. trifolii on host plant leaves treated at 26.16 microg/cm2 leaf surface.
Assuntos
Glucosídeos/farmacologia , Glicosídeos/farmacologia , Momordica charantia/química , Muscidae/fisiologia , Oviposição/efeitos dos fármacos , Triterpenos/farmacologia , Animais , Feminino , Glucosídeos/isolamento & purificação , Glicosídeos/isolamento & purificação , Muscidae/efeitos dos fármacos , Folhas de Planta/química , Triterpenos/isolamento & purificaçãoRESUMO
The American serpentine leaf mining fly, Liriomyza trifolii, whose larva feeds on more than 120 plant species is well characterized by its high degree of polyphagy. Observations on the oviposition behavior by L. trifolii demonstrated that among cucurbitaceous plants, Momordica charantia is rarely attacked by L. trifolii. The methanol extract of M. charantia leaves strongly deterred the females from ovipositing on kidney bean leaves treated at a concentration of 1 g leaf equivalent extract/ml. Analysis of the polar fraction of the methanol extract of M. charantia leaves resulted in the isolation of a novel cucurbitane glucoside, 7-O-beta-D-glucopyranosyl-3,23-dihydroxycucurbita-5,24-dien-19-al, named momordicine IV, along with another known compound, momordicine II. Momordicine II and IV deterred oviposition by L. trifolii significantly when bioassays were carried out on kidney bean leaves treated at 75.6 and 20.3 microg/cm2 leaf surface, respectively. There was no synergistic effect on oviposition deterrent when the two compounds were combined in their natural abundance.