1,720,979 research outputs found
Untargeted Metabolomics of Tomato Plants after Root-Knot Nematode Infestation
No full textAfter 2 months from the infestation of tomato plants with the root-knot nematode (RKN) Meloidogyne incognita, we performed a gas chromatography-mass spectrometry untargeted fingerprint analysis for the identification of characteristic metabolites and biomarkers. Principal component analysis, and orthogonal projections to latent structures discriminant analysis suggested dramatic local changes of the plant metabolome. In the case of tomato leaves, β-alanine, phenylalanine, and melibiose were induced in response to RKN stimuli, while ribose, glycerol, myristic acid, and palmitic acid were reduced. For tomato stems, upregulated metabolites were ribose, sucrose, fructose, and glucose, while fumaric acid and glycine were downregulated. The variation in molecular strategies to the infestation of RKNs may play an important role in how Solanum lycopersicum and other plants adapt to nematode parasitic stress
Haloacetophenones as newly potent nematicides against Meloidogyne incognita
No full textAcetophenones are a class of aromatic compounds frequently produced by plants as a response to a stress or as a protection reaction against parasites or herbivors. In the present research, we investigated the role of the carbonyl moiety in a series of commercially available aromatic ketones tested for their nematicidal activity against the root-knot nematode Meloidogyne incognita (Kofoid et White) Chitwood. Interestingly, we found that the presence of electron withdrawing groups onto the aromatic ring were highly efficient in inducing nematode paralysis and death (EC50/24h between 2.5 and 54.8mg/L and EC50/72h between 2.3 and 65.6mg/L, respectively). Moreover, a chlorine atom in α-position to the carbonyl functionality emerged as a key residue in improving acetophenones activity. In this paper, the nematicidal ability of a series of differently substituted acetophenones is reported and the preliminary structure-activity relationship studies are also discussed. We also performed an in vitro GC-MS metabolomics analysis on the potato cyst nematode Globodera pallida, after treatment with 2,4'-dichloroacetophenone (6) at 100mg/L for 24h. The 1-dodecanol and talose were evidenced as the main upregulated metabolites, suggesting a possible V-ATPase dysfunction
Nematicidal activity of some essential plant oils from tropical West Africa
No full textPlant parasitic nematodes are among the most destructive plant pathogens worldwide and their control is very challenging. Plant essential oils (EOs) have showed a great potential in nematode control. In this work, EOs from 10 aromatic plants acclimatized in Togo were assessed in vitro for their nematicidal activity on the root-knot nematode Meloidogyne incognita. EOs were subsequently analyzed by GC-MS and compounds were tested individually on nematodes. The most potent EOs were: Ocimum sanctum L., Cymbopogon schoenanthus (L.) Spreng and Cinnamomum zeylanicum Blume with EC 50/72h values of 282 ± 53, 288 ± 30 and 355 ± 126 mg/L, respectively. The EC 50/48h values of tested compounds were 81 ± 14, 117 ± 33, 128 ± 42, 141 ± 47, 168 ± 40, 216 ± 86 and 235 ± 43 mg/L for cinnamyl acetate, methyl eugenol, cinnamyl alcohol, acetyl eugenol, isoeugenol, eugenol and benzyl benzoate, respectively. Furthermore, we found a synergistic nematicidal activity when we combined phenylpropanoids compounds with carvone. EOs and their constituents described herein merit further studies, especially in pot experiments before serving as nematicides
Chemical Composition of Different Extracts of Conyza bonariensis: Insecticidal and Nematicidal Activities
Full text linkC. bonariensis (L.) Cronq. known as hairy fleabane was first described in Argentina but it is now widely spread through most warmer regions of Europe,
Africa, Asia, the Caribbean and Central America. In this work, a chemical
analysis by liquid and gas chromatography coupled with mass spectrometry
of the whole plant, aerial part, flowers and roots extracts of C. bonariensis
harvested in Togo (West Africa) was carried out. Two acetylenic compounds
Lachnophyllum ester and limonene were identified as the main components
of essential oils while Lachnophyllum and Matricaria lactones were dominant
in chloroform extracts. Based on the plant chemical compositions, essential
oils and chloroform extracts were tested on cowpea weevil Callosobruchus
maculatus adults which are considered as one of the most cosmopolitan pests
of stored beans, and on freshly hatched second-stage juveniles of root-knot
nematode Meloidogyne incognita. Results showed that the whole plant essential oil demonstrated an LC50/24h value of 1.75 μL oil/L air on C. maculatus
while at 3.91 μL oil/L air, it showed 100% mortality. Furthermore, the plant
root chloroform extracts partitioned in diethyl ether-hexane mixture showed
the strongest nematicidal activity with an LC50/72h value of 0.47 mg/mL. Our
findings suggest that the widely diffused plant C. bonariensis and its acetylenic constituents could be considered as potent botanical insecticidal and
nematicidal agents
Biocidal effect of (E)-anethole on the cyanobacterium Aphanizomenon gracile Lemmermann
No full textBiocidal natural substances of botanical origin offer a promising ecofriendly option for controlling toxic cyanobacteria. Herein, we study 11 essential oils and some of their major components for their activity on Aphanizomenon gracile. On the basis of our results we support that Origanum vulgare and O. dictamnus, Ocimum basilicum, Eucalyptus meliodora, Melissa officinalis, and Pimpinella anisum exhibited the strongest activities, and the IC50/1d values of the extracts were calculated to be between 168.43 and 241.97 μg mL−1. When the major components of the biocidal essential oils were tested individually, (E)-anethole was found active, exhibiting an IC50/1d value of 71.35 μg mL−1. On the other hand, the half-life (t1/2) of (E)-anethole was calculated at 1 h. A preliminary attempt of (E)-anethole microencapsulation was conducted, in order to slowly release this biocidal agent, increasing the residual life under open air conditions and thus the biological activity. Results were promising since the microencapsulated product exhibited better activity than did the non-formulated (E)-anethole. This is a first report on the biocidal activity of EOs and (E)-anethole on A. gracile and a preliminary indication of the microencapsulated (E)-anethole potential use as a natural biocidal in fresh waters
Comparative Metabolomic Profiling of Eggs from 3 Diverse Chicken Breeds Using GC-MS Analysis
Full text linkEggs, as a crucial source of essential
nutrients for consumers, possess a high nutritional value
owing to their rich composition of vital components essential for human health. While previous research has extensively investigated genetic factors influencing egg quality,
there has been a limited focus on exploring the impact of
specific strains, particularly within the African context, on
the polar metabolite profile of eggs. In this extensive study,
we conducted an untargeted analysis of the chemical composition of both albumen and yolk from 3 distinct strains
of hens—Blue Holland, Sasso, and Wassache—raised
under identical feeding conditions. Utilizing gas chromatography coupled with mass spectrometry (GC-MS), we
meticulously examined amino acids, carbohydrates, fatty
acids, and other small polar metabolites. In total, 38 and
44 metabolites were identified in the whites and yolk,
respectively, of the 3 studied strains. The application of
chemometric analysis revealed notable differences in
metabolite profiles with 8 relevant metabolites in each egg
part. These metabolites include amino acids (N-a-AcetylL-lysine, lysine, L-valine, L-Tryptophan), fatty acids
(oleic acid, linoleic acid, palmitic acid and stearic acid),
and carbohydrates (d-glucose, maltose, lactose). These
findings shed light on strain-specific metabolic nuances
within eggs, emphasizing potential nutritional implications. The ensuing discussion delves into the diverse metabolic pathways influenced by the identified metabolites,
offering insights that contribute to a broader understanding of egg composition and its significance in tailoring
nutritional strategies for diverse populations
Potent nematicidal activity of maleimide derivatives on Meloidogyne incognita
No full textDifferent maleimide derivatives were synthesized and assayed for their in vitro activity on the soil inhabiting, plant-parasitic nematode Meloidogyne incognita, also known as root-knot nematode. The compounds maleimide, N-ethylmaleimide, N-isopropylmaleimide, and N-isobutylmaleimide showed the strongest nematicidal activity on the second stage juveniles of the root-knot nematode with EC50/72h values of 2.6 ± 1.3, 5.1 ± 3.4, 16.2 ± 5.4, and 19.0 ± 9.0 mg/L, respectively. We also determined the nematicidal activity of copper sulfate, finding an EC50 value of 48.6 ± 29.8 mg/L. When maleimide at 1 mg/L was tested in combination with copper sulfate at 50 mg/L, we observed 100% mortality of the nematodes. We performed a GC-MS metabolomics analysis after treating nematodes with maleimide at 8 mg/L for 24 h. This analysis revealed altered fatty acids and diglyceride metabolites such as oleic acid, palmitic acid, and 1-monopalmitin. Our results suggest that maleimide may be used as a new interesting building block for developing new nematicides in combination with copper salt
Comparative lipid composition and GC–MS fatty acid profiling of tropical African freshwater fishes
Full text linkIn dietary contexts, fish are renowned for the diverse array of unsaturated fatty acids they provide to the body. While data regarding the fatty acid composition of freshwater fish are readily available in most developed countries, research on African freshwater fish remains notably limited. In this study, we investigated the fatty acid composition of fifteen freshwater fish species from Africa, primarily Afrotropical regions. Lipids were extracted using a solvent mixture of methanol, water, and chloroform. Subsequently, total fatty acids were determined by saponification, and the fatty acid profile was analyzed via GC–MS following methylation in the presence of BF3 and methanol. The results revealed lipid levels in fish fillets ranging from 1.99 % for T. guineensis to 6.41 % for M. bananensis. Total fatty acid percentages of lipids were found to be 81.40 ± 9.15 % for S. nigripinnis, 83.75 ± 6.12 % for L. niloticus, and 92.99 ± 11.30 % for C. dageti. The fatty acid profiles of 15 properly identified fish species have been determined, with the majority being identified for the first time. The composition of health-important omega-3 fatty acids EPA and total DHA ranged from 4.82 ± 0.2 % for Cyprinus lepidotus to 17.43 ± 2.50 % for Mugil bananensis. Unsupervised multivariate data analysis of fatty acid profiles of the different fish species showed significant differences. When the fish were grouped into 4 categories based on their similarities, 12 discriminant fatty acids characteristic of each group were identified. Among these fatty acids are omega-6 acids such as γ-linolenic acid and arachidonic acid, and omega-3 7,10,13,16,19-docosapentaenoic acid (DPA). This research opens avenues for consumers to make informed dietary choices aligned with their specific fatty acid needs and preferences regarding fish consumption
Exploration of New Oxidative Stress Nematicidal Compounds and Valorization of Satureja montana L. Essential Oils and Hydrolates as Plant Biopesticides
Full text linkPlant diseases cause economic challenges because they are responsible for estimated pre- and
postharvest losses of 16–28% of crops yearly. Control is aimed at the use of chemical
protectants, which reduce or retard the growth of the pathogen population. Another option is
the use of resistant varieties, which reduce the pest population or increase recovery from injury
caused by the enemies. However, resistant varieties become susceptible after few years of
cultivation due to pathogen adaptation and evolution to cultivated varieties.
Research of new environmentally benign products active against pests and diseases are
required that control target organisms without harming the environment. In this thesis, I
evaluated for the first time the nematicidal activity of new synthesized maleimide derivatives
by structure-activity relationship (SAR), some selected haloacetophenones and transition metal
ions. I also developed a new method to assess the metabolome alteration induced by these
products on nematodes. Finally, I valorized a carvacrol chemotype domesticated plant of S.
montana by evaluating its activity on insects, Spodoptera littoralis, Myzus persicae and
Rhopalosiphum padi; and on the root-knot nematode Meloidogyne javanica.
The maleimide derivatives were easily synthesized in a one pot reaction; haloacetophenones
were commercially available and metal ions present as sulphate or nitrate salts. The tested
compounds showed strong nematicidal activity against Meloidogyne incognita, X. index and
G. pallida with EC50 values lower than 5 mg/L. I also found a synergism action between
maleimide and copper ion on one hand and between copper ions and tannins on the other hand.
A GC-MS metabolomics analysis showed that these compounds might induce oxidative stress
in nematodes by modifying the levels of fatty acids and acylglycerols. After a field experiment
and phytotoxicity assays, these first reported nematicidal compounds could be used in crop protection against nematodes.
S. montana essential oil (EO) chemical composition was influenced by the fertilizers applied
and the EO extraction method. Hence, the conventional agriculture plants showed a lower level
of p-cymene with a higher level of carvacrol while more than 20 compounds showed
significantly difference levels according to the method of extraction, laboratory or semiindustrial. The EOs and the organic phase of hydrolates with LC50 values of 20-65 μg/cm2
modified the feeding behavior of Spodoptera. littoralis. S. montana EOs repel Rhopalosiphon.
padi and Myzus. persicae with settlement inhibition LC50 values estimated at 25-60 μg/cm2.
The plant also inhibited the germination and growth of Lolium perenne at 10 mg/mL.
Furthermore, ethanol extracts of S. montana did not show any activity on the pests. However,
we successfully valorized the EO by product hydrolates on the insects and nematode
Structural Elucidation of Relevant Gibberellic Acid Impurities and <i>In Silico</i> Investigation of Their Interaction with Soluble Gibberellin Receptor GID1
Full text linkGibberellin derivatives
are
a family of tetracyclic
diterpenoid plant hormones used in agriculture as plant growth regulators
included in the European Directive 91/414. In the pesticide peer review
process and to assess their toxicological relevance and product chemical
equivalence, the European Food Safety Authority (EFSA) highlighted
data gaps such as the identification of hydrolysis products and unknown
impurities. The aspect of impurity characterization and quantitation
is challenging and requires the use of hyphenated analytical techniques.
In this regard, we used an LC-QTOF/MS and NMR analysis for the characterization
of gibberellic acid impurities found in technical products. Gibberellic
acid impurities such as gibberellin A1 (GA1), 3-isolactone gibberellic acid (iso-GA3), gibberellenic acid, 1α,2α-epoxygibberellin
A3 (2-epoxy- GA3), and (1α,2β,3α,4bβ,10β)-2,3,7-trihydroxy-1-methyl-8-methylenegibb-4-ene-1,10-dicarboxylic
acid were identified and successfully characterized. Moreover, an in silico investigation on selected gibberellic acid impurities
and derivatives and their interactions with a gibberellin insensitive
dwarf1 (GID1) receptor has been carried out by means of induced fit
docking (IFD), generalized-Born surface area (MM-GBSA), and metadynamics
(MTD) experiments. A direct HPLC method with DAD and MS for the detection
of gibberellic acid and its impurities in a technical sample has been
developed. Moreover, by means of the in silico characterization
of the GID1 receptor-binding pocket, we investigated the receptor
affinity of the selected gibberellins, identifying compounds (2) and (4) as the most promising hit to lead
compounds
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