scholarly journals Insecticidal Pregnane Glycosides from the Root Barks of Periploca sepium

2016 ◽  
Vol 11 (10) ◽  
pp. 1934578X1601101
Author(s):  
Renfeng Li ◽  
Ximei Zhao ◽  
Baojun Shi ◽  
Shaopeng Wei ◽  
Jiwen Zhang ◽  
...  

To explore novel lead compounds for botanical pesticides from natural sources, a new pregnane glycoside (periplocoside) P2 as well as its isomer, a known pregnane glycoside P1, were isolated from the root barks of Periploca sepium using a bioactivity-guided method, and their structures were confirmed by 1D NMR, 2D NMR, IR, ESI-MSn and HRMS. Their insecticidal activities were evaluated against 3rd instar larvae of M. separata, and the results indicated that P2 exhibited excellent insecticidal activity with LC50 values of 2.9 and 2.2 mg/mL after 24 and 48 h, respectively, much lower than those of the positive control celangulin-V (24.7 and 21.0 mg/mL after 24 and 48 h, respectively). This work demonstrated that pregnane glycosides from Periploca sepium could be promising lead compounds for developing botanical pesticides urgently needed in agriculture.

2015 ◽  
Vol 77 (2) ◽  
Author(s):  
Vinod Kumar ◽  
Chandra Shekhar Mathela ◽  
Geeta Tewari ◽  
Ajay Kumar Pandey

(7R)-trans, trans-nepetalactone; a monoterpene iridoid (1) and acetylenic compound named cis-lachnophyllum ester (2) were isolated from the essential oils of Nepeta elliptica and Erigeron annuus, respectively and characterized using a combination of their spectral data  (1D-and 2D-NMR, MS, IR). Compound 1 and 2 were tested for biopesticide activity against mustard aphid, Lipaphis erysimi (Kalt.). Compound 1 exhibited high insecticidal activity towards L. erysimi with LC50 values of 2.18 and 2.73 mg/mL; LT50 values of 15.24 and 17.18 h. Compound 2 also displayed significant insecticidal activity having LC50 values of 0.85 and 4.70 mg/mL; LT50 values of 13.25 and 26.2 h. The activity of compounds 1 and 2 were comparable with synthetic pesticide, monocrotophos used as positive control and thus has potential as natural pesticides for use in economically important crops.


Molecules ◽  
2019 ◽  
Vol 24 (10) ◽  
pp. 1976 ◽  
Author(s):  
Yankai Li ◽  
Jiaqi Wei ◽  
Jiameng Fang ◽  
Wenbo Lv ◽  
Yufei Ji ◽  
...  

A new lignan (T4) and three known lignans (T1, T2, and T3) were isolated from the methanol extract of the roots of Phryma leptostachya using bioassay-guided method, and their structures were identified as phrymarolin I (T1), II (T2), haedoxan A (T3), and methyl 4-((6a-acetoxy-4-(6-methoxybenzo[d][1,3]dioxol-5-yl)tetrahydro-1H,3H-furo[3,4–c]furan-1-yl)oxy)-1-hydroxy-2,2-dimethoxy-5-oxocyclopent-3-ene-1-carboxylate (T4) byNMR and ESI-MS spectral data. Bioassay results revealed that haedoxan A exhibited remarkably high insecticidal activity against Mythimna separata with a stomach toxicity LC50 value of 17.06 mg/L and a topical toxicity LC50 value of 1123.14 mg/L at 24 h, respectively. Phrymarolin I and compound T4 also showed some stomach toxicity against M. separata with KD50 values of 3450.21 mg/L at 4 h and 2807.10 mg/L at 8 h, respectively. In addition, phrymarolin I and haedoxan A exhibited some stomach toxicity against Plutella xylostella with an LC50 value of 1432.05 and 857.28 mg/L at 48 h, respectively. In conclusion, this study demonstrated that lignans from P. leptostachya are promising as a novel class of insecticides or insecticide lead compounds for developing botanical pesticides.


2018 ◽  
Vol 13 (4) ◽  
pp. 1934578X1801300
Author(s):  
Xin Xi ◽  
Ximei Zhao ◽  
Feng Zhu ◽  
Jielu Wei ◽  
Zhan Hu ◽  
...  

To search for improved insecticidal compounds based on β-dihydroagarofuran sesquiterpenoids, forty-four β-dihydroagarofuran acetal derivatives were designed and synthesized. Insecticidal activities and structure-activity relationship of these target compounds were evaluated. Some of the newly synthesized β-dihydroagarofuran acetal compounds were found to show higher insecticidal activity against sixth-instar larvae of Mythimna separate. Especially, compounds 2.2.9, 2.2.10, 2.2.11, 2.3.4, 2.3.6, 2.3.7, 2.5.4, 2.5.7 had great insecticidal activities with lower LD50 than that of the positive control celangulin-V (110.13 μg/g). It deserves mentioning that compound 2.2.11 showed the lowest LD50 (60.33 μg/g) among these compounds. Structure-activity relationship results suggested that the substituent groups of 1-, 6- and 9-positions of the target structures could greatly affect the insecticidal activity. Especially, when the substituent groups of 6-position were n-propyl, n-butyl, allyl, propargyl, o-fluorobenzyl, and p-fluorobenzyl, the compounds showed outstanding insecticidal activities.


2020 ◽  
Vol 23 (2) ◽  
pp. 111-118
Author(s):  
Zhiping Che ◽  
Jinming Yang ◽  
Di Sun ◽  
Yuee Tian ◽  
Shengming Liu ◽  
...  

Background: It is one of the effective ways for pesticide innovation to develop new insecticides from natural products as lead compounds. Quinine, the main alkaloid in the bark of cinchona tree as well as in plants in the same genus, is recognized as a safe and potent botanical insecticide to many insects. The structural modification of quinine into 9R-acyloxyquinine derivatives is a potential approach for the development of novel insecticides, which showed more toxicity than quinine. However, there are no reports on the insecticidal activity of 9Racyloxyquinine derivatives to control Mythimna separata. Methods: Endeavor to discover biorational natural products-based insecticides, 20 novel 9Racyloxyquinine derivatives were prepared and assessed for their insecticidal activity against M. separata in vivo by the leaf-dipping method at 1 mg/mL. Results: Among all the compounds, especially derivatives 5i, 5k and 5t exhibited the best insecticidal activity with final mortality rates of 50.0%, 57.1%, and 53.6%, respectively. Conclusion: Overall, a free 9-hydroxyl group is not a prerequisite for insecticidal activity and C9- substitution is well tolerated; modification of out-ring double-bond is acceptable, and hydrogenation of double-bond enhances insecticidal activity; Quinine ring is essential and open of it is not acceptable. These preliminary results will pave the way for further modification of quinine in the development of potential new insecticides.


2022 ◽  
Vol 9 ◽  
Author(s):  
Jun Tang ◽  
Xueshuang Huang ◽  
Ming-Hang Cao ◽  
Zhiyan Wang ◽  
Zhiyin Yu ◽  
...  

During a screening for antifungal secondary metabolites, six new mono-/bis-alkenoic acid derivatives (2–7) and one known alkenoic acid derivative (1) were isolated from an endophytic fungi Scopulariopsis candelabrum. Their chemical structures were identified by 1H-NMR, 13C-NMR, 2D NMR, and high-resolution mass spectrometry, as well as comparisons with previously reported literatures. Among them, fusariumesters C‒F (2–5) are bis-alkenoic acid derivatives dimerized by an ester bond, while acetylfusaridioic acid A (6) and fusaridioic acid D (7) are alkenoic acid monomers. All the isolates were submitted to an antifungal assay against Candida albicans and the corn pathogen Exserohilum turcicum using the filter paper agar diffusion method. As a result, only compound 1 decorating with β-lactone ring turned out to be active against these two tested fungi. The broth microdilution assay against Candida albicans showed the minimum inhibitory concentration (MIC) value of 1 to be 20 μg/ml, while the minimum inhibitory concentration value of the positive control (naystatin) was 10 μg/ml. And the half maximal inhibitory concentration (IC50) value (21.23 μg/ml) of 1 against Exserohilum turcicum was determined by analyzing its inhibition effect on the mycelial growth, using cycloheximide (IC50 = 46.70 μg/ml) as the positive control.


Planta Medica ◽  
2021 ◽  
Author(s):  
Julianna Max ◽  
Jörg Heilmann

Abstract 1H NMR-guided fractionation of the petroleum ether extract of the aerial parts from Hypericum hirsutum yielded to the isolation of 19 polyprenylated polycyclic acylphloroglucinols. Structure elucidation based on 1D and 2D NMR spectroscopy together with high-resolution electrospray ionization mass spectroscopy revealed 14 acylphloroglucinols with a homoadamantane scaffold (1–14), while 5 further compounds showed an adamantane skeleton (15–19). Except for hookerione C (15), all isolated metabolites are hitherto unknown. While structurally-related metabolites have been isolated from other Hypericum species, it is the first report of admantan and homoadamantan type acylphloroglucinols in section Taeniocarpium Jaub. & Spach (Hypericaceae). The isolated compounds have been tested in a crystal violet-based in vitro assay on their properties to reduce the proliferation of human microvascular endothelial cells compared to hyperforin as the positive control. They showed a moderate reduction of proliferation with IC50 values in the range ~ 3 – 22 µM, with the homoadamantane-based compounds 2 and 4 being the most active. In addition, inhibition of the TNF-α-induced ICAM-1 expression was determined for 1 – 5, 7, and 10 – 12. Substances 3 and 12 reduced the ICAM-1 expression significantly (to 46.7% of control for 3, 62.3% for 12, at 50 µM).


2018 ◽  
Vol 42 (4) ◽  
pp. 408-419 ◽  
Author(s):  
Ellison Rosario de Oliveira ◽  
Dejane Santos Alves ◽  
Geraldo Andrade Carvalho ◽  
Bárbara Maria Ribeiro Guimarães de Oliveira ◽  
Smail Aazza ◽  
...  

ABSTRACT Fall armyworm (FAW) (Spodoptera frugiperda) is a polyphagous insect responsible for damage to several crops. Synthetic chemical insecticides and genetically modified plants are the most commonly used methods for FAW control. However, the selection of resistant populations has been reported in several studies, justifying the search for new molecules to be used in the control of S. frugiperda. The aim of the present study was to evaluate the toxicity of lemongrass (Cymbopogon flexuosus) essential oil (LEO) and its major component (citral) in relation to FAW. Additionally, the anticholinesterase activity of LEO and citral was evaluated using acetylcholinesterase (AChE) from Electrophorus electricus. The LEO was toxic to FAW when added to an artificial diet (LC50 = 1.35 mg mL-1) at the highest concentrations tested, and the median lethal time (LT50) was 18.85 h. Major components of LEO were identified by gas chromatography-mass spectrometry, and citral, the most abundant component, was used in FAW bioassays. The insecticidal activity of citral was statistically similar to that of LEO, demonstrating that citral was responsible for the insecticidal activity of LEO. Inhibition of AChE was measured, and the mean inhibitory concentration (IC50) values for LEO and citral were 650- and 405-fold higher, respectively, than that verified for the positive control (methomyl insecticide), suggesting selectivity for non-target organisms. Based on these results, citral and C. flexuosus have the potential to be applied in the development of new products for the control of S. frugiperda.


Planta Medica ◽  
2020 ◽  
Vol 86 (15) ◽  
pp. 1080-1088
Author(s):  
Thomas Goels ◽  
Elisabeth Eichenauer ◽  
Julia Langeder ◽  
Franziska Hoeller ◽  
Christina Sykora ◽  
...  

AbstractThe balm of the Norway spruce (Picea abies) is a well-known traditional herbal medicine used to cure wounds. Even though clinical trials have confirmed its empirical use, the active constituents, their mode of action, and the exact composition of this natural product are still unknown. In this study, the balm was subjected to fractionated extraction and further purified employing flash chromatography, HPLC-PDA-ELSD, preparative and analytical TLC. Hydroxycinnamic acids ( 1– 3), the lignan pinoresinol ( 4), four hydroxylated derivatives of dehydroabietic acid (DHAA) ( 5 –  8), and dehydroabietic acid ( 9) were isolated. Their structures were elucidated by LC-MS, 1D- and 2D-NMR. Four extracts, two commercially available resin acids–pimaric acid ( 10) and isopimaric acid ( 11)–and the isolated compounds were tested for increased re-epithelialization of cell-free areas in a human adult low calcium high temperature keratinocytes monolayer. Lysophosphatidic acid (10 µM) served as positive control and ranged between 100% and 150% rise in cell-covered area related to the vehicle control. Two extracts containing carboxylic acids and non-acidic apolar constituents, respectively, boosted wound closure by 47% and 36% at 10 and 3 µg/mL, respectively. Pinoresinol, DHAA, three of its hydroxylated derivatives, and pimaric and isopimaric acid as well as defined combinations of the hydroxylated DHAA derivatives led to a significantly enhanced wound closure by up to 90% at concentrations between 1 and 10 µM. Overall, lignans and diterpene resin acids, main constituents of Norway spruce balm, are able to increase migration or proliferation of keratinocytes in vitro. The presented data link the phytochemistry of this natural wound healing agent with boosted re-epithelialization.


2019 ◽  
Vol 14 (1) ◽  
pp. 1934578X1901400 ◽  
Author(s):  
Zhiping Che ◽  
Yuee Tian ◽  
Jinming Yang ◽  
Shengming Liu ◽  
Jia Jiang ◽  
...  

As our ongoing work on research of natural-product-based insecticidal agents, eighteen podophyllotoxin analogues with diverse chemical structures were evaluated for their insecticidal activities against the pre-fourth-instar larvae of Athetis dissimilis Hampson in vivo at the concentration of 1 mg/mL. Among all the reported analogues, compounds 6, 8, 12, 13, 15 and 17 showed more potent insecticidal activities than matrine, quinine and toosendanin, three commercial plant secondary metabolites. 2′,6′-Dichloropodophyllotoxin (8) and 2′,6′-dichloroepipodophyllotoxin (13) exhibited the most pronounced and promising insecticidal activity with the final corrected mortality rates of greatly 60%. This suggested that variation of chemical structures in the podophyllotoxin skeleton conspicuously has effect on the insecticidal activity profiles of podophyllotoxin analogues. Moreover, SAR revealed that the substituents and configuration were critical for their insecticidal activities. The results may be useful in guiding further design and structural modification of podophyllotoxins in the development of potential novel insecticidal agents.


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