A Review of Bioinsecticidal Activity of Solanaceae Alkaloids (original) (raw)
Related papers
Journal of Chemical Ecology, 2000
Structure-dose-feeding deterrency relationships were compared between the Colorado potato beetle, Leptinotarsa decemlineata (Say), and the western corn rootworm, Diabrotica virgifera virgifera LeConte, using 15 alkaloids, terpenoids, and phenolic derivatives. The former species, a specialist herbivore on selected alkaloid-rich Solanaceae species, was on average 100-times less sensitive to the antifeedant effects of alkaloids, but more similarly sensitive to the terpenoids and phenolics than the latter species, a generalist flower herbivore predominantly on Graminae, Cucurbitaceae, and Compositae species. Antifeedant ED50 values for the potato beetle and corn rootworm, each from closely related subfamilies of Chrysomelidae, ranged over four orders of dose magnitude among the 15 compounds with major species differences in stereosensitivity to 0-hydrastines and analog sensitivity with the sitphinenes. Extremes in sensitivity ranged from silphinene, a rare tricyclic sesquiterpene that is 53 times more active on the potato beetle to aconitine, which is 430 times more antifeedant to the corn rootworm. Among
Medicinal Plants of Solanum Species: The Promising Sources of Phyto-Insecticidal Compounds
Journal of Tropical Medicine
Several medicinal plants have the potential to be a promising alternative pharmacological therapy for a variety of human illnesses. Many insects, including mosquitoes, are important vectors of deadly pathogens and parasites, which in the world’s growing human and animal populations can cause serious epidemics and pandemics. Medicinal plants continue to provide a large library of phytochemicals, which can be used to replace chemically synthesized insecticides, and utilization of herbal product-based insecticides is one of the best and safest alternatives for mosquito control. Identifying new effective phyto-derived insecticides is important to counter increasing insect resistance to synthetic compounds and provide a safer environment. Solanum genus (Solanaceae family or nightshades) comprises more than 2500 species, which are widely used as food and traditional medicine. All research publications on insecticidal properties of Solanaceae plants and their phytoconstituents against mosq...
Plant Defense and Insect Adaptation with Reference to Secondary Metabolites
Reference Series in Phytochemistry
Insects pose a great threat to plants, and plants, in turn, withstand to insect attack through various morphological and biochemical traits. Among the plant defensive traits, secondary metabolites play a major role against insect herbivory as they are highly dynamic. They either occur constitutively in plants or are induced in response to insect herbivory. These metabolites include sulfur-(terpenes and flavonoids) and nitrogen-containing metabolites (alkaloids, cyanogenic glucosides, and nonprotein amino acids), which are being implicated by plants against insect pests. Plant secondary metabolites either are directly toxic to insect pests or mediate signaling pathways that produce plant toxins. Further, some of the plant secondary metabolites act through antixenosis mode by developing non-preference in host plant to the insect pests. However, some plant secondary metabolites recruit natural enemies of the insect pests, thus indirectly defending plants against insect pests. However, insects have developed adaptations to these plant secondary metabolites. In this chapter, important plant secondary metabolites, their mechanism of action against insect pests, counter-adaptation by insects, and promising advances and challenges are discussed.
Pyrrolizidine alkaloids between plants and insects: A new chapter of an old story
Chemoecology, 1994
Among alkaloids the pyrrolizidine alkaloids (PAs) play a unique role in the interactions between plants and adapted insects. In Senecio spp. (Asteraceae) PAs are synthesized in the roots as alkaloid N-oxides which are specifically translocated into shoots via the phloem-path and channeled to the preferred sites of storage (e.g. inflorescences) where they are stored in the cell vacuoles. In different Senecio spp. senecionine Noxide is produced as the common product of biosynthesis, which subsequently via a number of simple but specific reactions is transformed into typical speciesspecific PA-patterns. Insects from diverse taxa sequester PAs for their own defense. Lepidopterans (e.g. arctiids such as Tyria jacobaeae and Creatonotos transiens) may hydrolyze plant acquired ester-PAs and convert the resulting necine base into insect-specific PAs by esterification with an acid of their own metabolism. Adapted arctiids and the grasshopper Zonocerus take up PAs in the state of the tertiary amine. N-Oxides are reduced in the guts prior to uptake. In the bodies the tertiary PAs are rapidly N-oxidized by a specific mixed-function oxigenase and are maintained in the N-oxide state. The importance of the reversible interconversion of the nontoxic N-oxide (pro-toxine) into the toxic tertiary alkaloid is discussed as the specific feature of PAs in plant-insect interactions.
Journal of Chemical Ecology, 2014
Pyrrolizidine alkaloids (PAs) are feeding deterrents and toxic compounds to generalist herbivores. Among the PAs of Jacobaea vulgaris Gaertn, jacobine and erucifoline are the most effective against insect herbivores as indicated by correlative studies. Because little is known about the effect of jacobine and erucifoline as individual PAs, we isolated these compounds from their respective Jacobaea chemotypes. These PAs and other commercially available senecioninelike PAs, including senecionine, seneciphylline, retrorsine, and senkirkine, were tested as free base and N-oxide forms at a range of 0-70 ppm. Feeding bioassays using live insects are closer to the natural pattern but require relatively large amounts of test compounds. We, therefore, compared the toxicity of PAs using both Spodoptera exigua cell line and larval injection bioassays. Both bioassays led to similar results in the order of PA toxicity, indicating that the cell lines are a valuable tool for a first toxicity screen. Testing individual PAs, jacobine and erucifoline were the most toxic PAs, suggesting their major role in plant defense against generalist herbivores. Senkirkine and seneciphylline were less toxic than jacobine and erucifoline but more toxic than retrorsine. Senecionine was not toxic at the tested concentrations. For all toxic PAs, the free base form was more toxic than the N-oxide form. Our results demonstrate that structural variation of PAs influences their effectiveness in plant defense.
Plant Alkaloids: Main Features, Toxicity, and Mechanisms of Action
Springer eBooks, 2015
Alkaloids are one of the largest groups of plant secondary metabolites, being present in several economically relevant plant families. Alkaloids encompass neuroactive molecules, such as caffeine and nicotine, as well as life-saving medicines including emetine used to fight oral intoxication and the antitumorals vincristine and vinblastine. Alkaloids can act as defense compounds in plants, being efficient against pathogens and predators due to their toxicity. Fast perception of aggressors and unfavorable environmental conditions, followed by efficient and specific signal transduction for triggering alkaloid accumulation, are key steps in successful plant protection. Toxic effects, in general, depend on specific dosage, exposure time, and individual characteristics, such as sensitivity, site of action, and developmental stage. At times, toxicity effects can be both harmful and beneficial depending on the ecological or pharmacological context. Different strategies are used to study alkaloid metabolism and accumulation. An efficient approach is to monitor gene expression, enzyme activities, and concentration of precursors and of the alkaloid itself during controlled attacks of pathogens and herbivores or upon the simulation of their presence through physical or chemical stimulation. Detailed understanding of alkaloid biosynthesis and mechanisms of action is essential to improve production of alkaloids of interest, to discover new bioactive molecules, and to sustainably exploit them against targets of interest, such as herbivores, pathogens, cancer cells, or unwanted physiological conditions.
Journal of Environmental Engineering and Landscape Management, 2021
Brinjal or eggplant (Solanum melongena L.) is known as a vegetable of diet because it contains high moisture and low calorific value. It is also a good source of antioxidants and phytonutrients. Brinjal is widely grown in the South and South-East Asian countries and is the second most important vegetable in India. It belongs to the Solanaceae family. Shoot and fruit borer (Leucinodes orbonalis) pest of brinjal is the most widespread one and it has the ability to affect any of the developmental stages of brinjal. Plants and their insect herbivores have had a long and intimate evolutionary association that has resulted in many complex interactions mediated by specialized plant metabolites like phenolics, alkaloids, terpenoids, cyanogenic glycosides etc. Frequent and excessive use of insecticides has become a common practice now which only increases the probability of resistance development and resurgence of pest. Hence to develop an effective approach to combat this pest understanding...