scholarly journals Plumbagin, a Potent Naphthoquinone from Nepenthes Plants with Growth Inhibiting and Larvicidal Activities

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 825
Author(s):  
Asifur Rahman-Soad ◽  
Alberto Dávila-Lara ◽  
Christian Paetz ◽  
Axel Mithöfer

Some plant species are less susceptible to herbivore infestation than others. The reason for this is often unknown in detail but is very likely due to an efficient composition of secondary plant metabolites. Strikingly, carnivorous plants of the genus Nepenthes show extremely less herbivory both in the field and in green house. In order to identify the basis for the efficient defense against herbivorous insects in Nepenthes, we performed bioassays using larvae of the generalist lepidopteran herbivore, Spodoptera littoralis. Larvae fed with different tissues from Nepenthes x ventrata grew significantly less when feeding on a diet containing leaf tissue compared with pitcher-trap tissue. As dominating metabolite in Nepenthes tissues, we identified a naphthoquinone, plumbagin (5-hydroxy-2-methyl-1,4-naphthoquinone). When plumbagin was added at different concentrations to the diet of S. littoralis larvae, an EC50 value for larval growth inhibition was determined with 226.5 µg g−1 diet. To further determine the concentration causing higher larval mortality, sweet potato leaf discs were covered with increasing plumbagin concentrations in no-choice-assays; a higher mortality of the larvae was found beyond 60 µg plumbagin per leaf, corresponding to 750 µg g−1. Plant-derived insecticides have long been proposed as alternatives for pest management; plumbagin and derivatives might be such promising environmentally friendly candidates.

2021 ◽  
Vol 7 (7) ◽  
pp. 499
Author(s):  
Nitsan Birnbaum ◽  
Victoria Reingold ◽  
Sabina Matveev ◽  
Chandrasekhar Kottakota ◽  
Michael Davidovitz ◽  
...  

Growing global population and environmental concerns necessitate the transition from chemical to eco-friendly pest management. Entomopathogenic fungi (EPF) are rising candidates for this task due to their ease of growing, broad host range and unique disease process, allowing EPF to infect hosts directly through its cuticle. However, EPF’s requirement for high humidity negates their integration into conventional agriculture. To mitigate this problem, we formulated Metarhizium brunneum conidia in an oil-in-water Pickering emulsion. Conidia in aqueous and emulsion formulations were sprayed on Ricinus communis leaves, and Spodoptera littoralis larvae were introduced under low or high humidity. The following were examined: conidial dispersion on leaf, larval mortality, conidial acquisition by larvae, effects on larval growth and feeding, and dynamic of disease progression. Emulsion was found to disperse conidia more efficiently and caused two-fold more adhesion of conidia to host cuticle. Mortality from conidia in emulsion was significantly higher than other treatments reaching 86.5% under high humidity. Emulsion was also found to significantly reduce larval growth and feeding, while conferring faster fungal growth in-host. Results suggest that a Pickering emulsion is able to improve physical interactions between the conidia and their surroundings, while weakening the host through a plethora of mechanisms, increasing the chance of an acute infection.


Author(s):  
Charles Oluwaseun Adetunji ◽  
Santwana Palai ◽  
Chika Precious Ekwuabu ◽  
Chukwuebuka Egbuna ◽  
Juliana Bunmi Adetunji ◽  
...  

2017 ◽  
Vol 15 (1) ◽  
pp. 332-343 ◽  
Author(s):  
Karolina A. Wojtunik-Kulesza ◽  
Katarzyna Targowska-Duda ◽  
Katarzyna Klimek ◽  
Grażyna Ginalska ◽  
Krzysztof Jóźwiak ◽  
...  

AbstractAlzheimer’s disease (AD) is by far the most prevalent of all known forms of dementia. Despite wide-spread research, the main causes of emergence and development of AD have not been fully recognized. Natural, low-molecular, lipophilic terpenoids constitute an interesting group of secondary plant metabolites, that exert biological activities of possible use in the prevention and treatment of AD. In order to identify secondary metabolites possessing both antioxidant activity and the potential to increase the level of acetylcholine, selected terpenoids have been screened for possible acetylcholinesterase inhibitory activity by use of two methods, namely Marston (chromatographic assay) and Ellman (spectrophotometric assay). In order to describe the interaction between terpenes and AChE active gorge, molecular docking simulations were performed. Additionally, all analyzed terpenes were also evaluated for their cytotoxic properties against two normal cell lines using MTT assay. The obtained results show that: carvone (6), pulegone (8) and γ-terpinene (7) possess desirable AChE inhibitory activity. MTT assay revealed low or lack of cytotoxicity of these metabolites. Thus, among the investigated terpenes, carvone (6), pulegone (8) and y-terpinene (7) can be recognized as compounds with most promising activities in the development of multi-target directed ligands.


Author(s):  
Parastou Farshi ◽  
Eda Ceren Kaya ◽  
Fataneh Hashempour-Baltork ◽  
Kianoush Khosravi-Darani

: Coronaviruses have caused worldwide outbreaks in different periods. SARS (severe acute respiratory syndrome), was the first emerged virus from this family, followed by MERS (Middle East respiratory syndrome) and SARS-CoV-2 (2019-nCoV or COVID 19), which is newly emerged. Many studies have been conducted on the application of chemical and natural drugs for treating these coronaviruses and they are mostly focused on inhibiting the proteases of viruses or blocking their protein receptors through binding to amino acid residues. Among many substances which are introduced to have an inhibitory effect against coronaviruses through the mentioned pathways, natural components are of specific interest. Secondary and primary metabolites from plants, are considered as potential drugs to have an inhibitory effect on coronaviruses. IC50 value (the concentration in which there is 50% loss in enzyme activity), molecular docking score and binding energy are parameters to understand the ability of metabolites to inhibit the specific virus. In this study we did a review of 154 papers on the effect of plant metabolites on different coronaviruses and data of their IC50 values, molecular docking scores and inhibition percentages are collected in tables. Secondary plant metabolites such as polyphenol, alkaloids, terpenoids, organosulfur compounds, saponins and saikosaponins, lectins, essential oil, and nicotianamine, and primary metabolites such as vitamins are included in this study.


2016 ◽  
pp. 135-168
Author(s):  
Tamoghna Saha ◽  
Nithya C. ◽  
Shyambabu S. ◽  
Kiran Kumari ◽  
S. N. Ray ◽  
...  

Author(s):  
Partha Pradip Adhikari ◽  
Satya Bhusan Paul

  Cleome genus includes 601 plant species from the family Cleomaceae. Of more than 600 plants, 206 (34.3%) plants are having accepted species names. Cleome gynandra Linn. is a well-known medicinal plant with traditional and pharmacological importance. A good number of secondary plant metabolites have also been isolated from different parts of C. gynandra. Our investigation confirms two mutant varieties of C. gynandra exists in India. Accordingly, the objective of this study was designed to critically evaluate the pharmacological and phytochemical evaluation of C. gynandra of two mutant variety, to provide a consolidated platform for research potential of both the mutant varieties of C. gynandra. Careful scrutiny reveals that the plant possesses a huge range pharmacological applications, such as anti-inflammatory, free radical scavenging, anticancerous, immunomodulator, and antidiabetic agents. To arrive its pharmacological importance the published papers also shown an enormous amount of phytochemicals endorsement. Scientific perusal reveals different parts of the plant has an immense medicinal importance which proofs its traditional use round the glove. But in North-Eastern region of India, the same plant abundantly found in pink mutant variety. To date, there is not much research investigation for this mutant variety to validate its pharmacological importance. Therefore, research needs to scrutinize and compare the medicinal claims of the pink mutant variety in the bio-diverse region of North-East India.


2020 ◽  
Vol 10 (2) ◽  
pp. 148-152
Author(s):  
Z.M. Anka ◽  
Vijender Singh ◽  
S.N. Gimba ◽  
Gunjan Singh

Millions of people in the world depend on traditional medicinal plants for treatment of many diseases.  They have curative properties due to presence of various complex chemical substances of different composition, which are found as secondary plant metabolites in one or more parts of these plants. These plant metabolites according to their composition are grouped as flavonoids, tannins, alkaloids, saponins etc. Guiera senegalensis(Gs), which grows in abundance in semi-desert area of Western Africa such as Nigeria, has been used for treating specific diseases and wounds. The study is carried out to investigate the phytochemical analysis, toxicity, and the antifungal activity of Gs leaves extract. Keywords: Guiera senegalensis, Antifungal activity, Brine shrimp, toxicity, phytochemical analysis;


2019 ◽  
Author(s):  
Justin Clements ◽  
Russell L. Groves ◽  
JoAnn Cava ◽  
Caroline Barry ◽  
Scott Chapman ◽  
...  

AbstractThe Colorado Potato Beetle, Leptinotarsa decemlineata, is a major agricultural pest of solanaceous crops in the United States. Historically, a multitude of insecticides have been used to control problematic populations. Due to increasing resistance to insecticides, novel compounds and methodologies are warranted for the control of beetle populations. Mixed-isomer conjugated linoleic acid has been studied in-depth for its beneficial properties to mammalian systems. At the same time, studies have demonstrated that conjugated linoleic acid can manipulate fatty acid composition in non-mammalian systems, resulting in embryo mortality. Consequently, experiments were conducted to assess the effects of foliar-applied conjugated linoleic acid on larval growth, embryogenesis, and feeding preference in Colorado potato beetle. Both maternal and deterrent effects of dietary conjugated linoleic acid were assessed. Conjugated linoleic acid demonstrated desirable insecticidal properties, including increased larval mortality, slowed larval development, antifeedant effects, and decreased egg viability after maternal ingestion.


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