scholarly journals Essential Oils from Clausena Species in China: Santalene Sesquiterpenes Resource and Toxicity against Liposcelis bostrychophila

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Shan-Shan Guo ◽  
Yang Wang ◽  
Zhen-Yang Chen ◽  
Zhe Zhang ◽  
Ju-Qin Cao ◽  
...  

To develop natural product resources from the Clausena genus (Rutaceae), the essential oils (EOs) from four Clausena plants (Clausena excavata, C. lansium, C. emarginata, and C. dunniana) were analyzed by GC-MS. Their lethal (contact toxicity) and sublethal effects (repellency) against Liposcelis bostrychophila (LB) adults were also evaluated. Santalene sesquiterpene was the precursor substance of santalol, a valuable perfumery. It was found that plenty of α-santalol (31.7%) and α-santalane (19.5%) contained in C. lansium from Guangxi Province and α-santalene (1.5%) existed in C. emarginata. Contact toxicity of the four EOs was observed, especially C. dunniana (LD50 = 37.26 µg/cm2). Santalol (LD50 = 30.26 µg/cm2) and estragole (LD50 = 30.22 µg/cm2) were the two most toxic compounds. In repellency assays, C. excavate, C. lansium, and C. emarginata exhibited repellent effect at the dose of 63.17 nL/cm2 2 h after exposure (percentage repellencies were 100%, 98%, and 96%, respectively). Four Clausena EOs and santalol had an excellent potential for application in the management of LB. Clausena plants could be further developed to find more resources of natural products.

2021 ◽  
Vol 14 (2) ◽  
pp. 89-98
Author(s):  
F. Sohrabi ◽  
M. Ziaee

Summary Tetranychus turkestani Ugarov and Nikolski is one of the main agricultural pests of southwestern Iran and some other tropical regions. In the present study, fumigant activity of three essential oils extracted from Rosmarinus officinalis L., Mentha longifolia L. and Eucalyptus globulus Labill., and contact toxicity of two biopesticides (Tondexir and Palizin) on T. turkestani mite females were investigated and compared with that of spiromesifen, a chemical acaricide. Also, sublethal effects of the tested compounds at 50% lethal concentration (LC50) were estimated on the biological parameters of T. turkestani. The LC50 values for E. globulus, R. officinalis and M. longifolia essential oils were 12.50, 11.52 and 4.00 μl/l air and for spiromesifen, Tondexir and Palizin were 10.98, 327.34 and 858.13 ppm, respectively. All tested compounds significantly reduced adult female longevity, equally to the chemical acaricide spiromesifen. Fecundity also decreased in all treatments and this reduction was even higher for plant essential oils than the other compounds. Palizin, E. globulus and M. longifolia significantly reduced the hatchability of T. turkestani eggs similarly to spiromesifen. According to the results, the tested plant compounds are effective against T. turkestani and may be applied as suitable alternatives to synthetic pesticides against this crop pest.


Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
NJ Sadgrove ◽  
IRH Telford ◽  
D Lyddiard ◽  
TL Collins ◽  
J Klepp ◽  
...  

2018 ◽  
Author(s):  
Jonathan J. Mills ◽  
Kaylib R. Robinson ◽  
Troy E. Zehnder ◽  
Joshua G. Pierce

The lipoxazolidinone family of marine natural products, with an unusual 4-oxazolidinone heterocycle at their core, represents a new scaffold for antimicrobial discovery; however, questions regarding their mechanism of action and high lipophilicity have likely slowed follow-up studies. Herein, we report the first synthesis of lipoxazolidinone A, 15 structural analogs to explore its active pharmacophore, and initial resistance and mechanism of action studies. These results suggest that 4-oxazolidinones are valuable scaffolds for antimicrobial development and reveal simplified lead compounds for further optimization.


2018 ◽  
Author(s):  
William A. Shirley ◽  
Brian P. Kelley ◽  
Yohann Potier ◽  
John H. Koschwanez ◽  
Robert Bruccoleri ◽  
...  

This pre-print explores ensemble modeling of natural product targets to match chemical structures to precursors found in large open-source gene cluster repository antiSMASH. Commentary on method, effectiveness, and limitations are enclosed. All structures are public domain molecules and have been reviewed for release.


2020 ◽  
Vol 17 (2) ◽  
pp. 82-90 ◽  
Author(s):  
Ghodsi Mohammadi Ziarani ◽  
Fatemeh Mohajer ◽  
Zohreh kheilkordi

Background: Natural products have been received attention due to their importance in human life as those are biologically active. In this review, there are some reports through different methods related to the synthesis of the indolizidine 195B which was extracted from poisonous frog; however, due to respect nature, the synthesis of natural compounds such as indolizidine has been attracted much attention among scientists and researchers. Objective: This review discloses the procedures and methods to provide indolizidine 195B from 1989 to 2018 due to their importance as a natural product. Conclusion: There are several methods to give rise to the indolizidine 195B as a natural product that is highly active from the biological perspective in pharmaceutical chemistry. In summary, many protocols for the preparations of indolizidine 195B from various substrates, several reagents, and conditions have been reported from different aromatic and aliphatic.


2021 ◽  
Author(s):  
Nengzhong Wang ◽  
Zugen Wu ◽  
Junjie Wang ◽  
Nisar Ullah ◽  
Yixin Lu

A comprehensive and updated summary of asymmetric organocatalytic annulation reactions is presented; in particular, the applications of these annulation strategies to natural products synthesis are highlighted.


2021 ◽  
Author(s):  
Ehsan Borzoui ◽  
Ramin Khaghani ◽  
Gadir Nouri-Ganbalani

Abstract Trogoderma granarium Everts, the Khapra beetle, is a major pest of stored products, especially grains. In this study, fumigant toxicity and sublethal effects of Eucalyptus camaldulensis Dehnh. (Myrtaceae) and Mentha piperita L. (Lamiaceae) essential oils (EOs) were investigated against different growth stages of T. granarium. To assess the sublethal effects, insects were exposed to an LC20 or LC50 concentration of each essential oil, and the ability of these oils to deter feeding, oviposition, and damage to wheat seeds and overall mass were surveyed. At LC50 concentrations, M. piperita EO showed higher fumigant toxicity than E. camaldulensis EO against eggs, 2nd instar larvae, 4th instar larvae, and adults of T. granarium. Furthermore, the adults were more sensitive to the tested EOs than immatures. In free-choice tests, both larvae and adults showed a preference for control-treated wheat seeds than for seeds treated with an LC20 or LC50 concentration of EOs from E. camaldulensis or M. piperita. In a no-choice test, adult females exposed to EOs showed lower fecundity and fertility in comparison to control females not exposed to EOs. Treatment of wheat seeds with E. camaldulensis or M. piperita EOs resulted in a dose-specific reduction in the number of damaged seeds and seed weight loss when compared to control. According to our results, both tested EOs, especially EOs extracted from M. piperita, showed good potential for use in integrated pest management strategies against T. granarium.


Metabolites ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 107
Author(s):  
Rafael de Felício ◽  
Patricia Ballone ◽  
Cristina Freitas Bazzano ◽  
Luiz F. G. Alves ◽  
Renata Sigrist ◽  
...  

Bacterial genome sequencing has revealed a vast number of novel biosynthetic gene clusters (BGC) with potential to produce bioactive natural products. However, the biosynthesis of secondary metabolites by bacteria is often silenced under laboratory conditions, limiting the controlled expression of natural products. Here we describe an integrated methodology for the construction and screening of an elicited and pre-fractionated library of marine bacteria. In this pilot study, chemical elicitors were evaluated to mimic the natural environment and to induce the expression of cryptic BGCs in deep-sea bacteria. By integrating high-resolution untargeted metabolomics with cheminformatics analyses, it was possible to visualize, mine, identify and map the chemical and biological space of the elicited bacterial metabolites. The results show that elicited bacterial metabolites correspond to ~45% of the compounds produced under laboratory conditions. In addition, the elicited chemical space is novel (~70% of the elicited compounds) or concentrated in the chemical space of drugs. Fractionation of the crude extracts further evidenced minor compounds (~90% of the collection) and the detection of biological activity. This pilot work pinpoints strategies for constructing and evaluating chemically diverse bacterial natural product libraries towards the identification of novel bacterial metabolites in natural product-based drug discovery pipelines.


Synthesis ◽  
2021 ◽  
Author(s):  
Dávid Roman ◽  
Maria Sauer ◽  
Christine Beemelmanns

Here, we have summarized more than 30 representative natural product syntheses published in 2015 to 2020 that employ one or more Horner-Wadsworth-Emmons (HWE) reactions. We comprehensively describe the applied phosphonate reagents, HWE reaction conditions and key steps of the total synthetic approaches. Our comprehensive review will support future synthetic approaches and serve as guideline to find the best HWE conditions for the most complicated natural products known


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