Chemical Characterization of Plant Extracts and Evaluation of their Nematicidal and Phytotoxic Potential

Abstract

Nacobbus aberrans ranks among the “top ten” plant-parasitic nematodes of phytosanitary importance. It causes significant losses in commercial interest crops in America and is a potential risk in the European Union. The nematicidal and phytotoxic activities of seven plant extracts against N. aberrans and Solanum lycopersicum were evaluated in vitro, respectively. The chemical nature of three nematicidal extracts (EC50,48h ≤ 113 µg mL−1) was studied through NMR analysis. Plant extracts showed nematicidal activity on second-stage juveniles (J2): (≥87%) at 1000 µg mL−1 after 72 h, and their EC50 values were 71.4–468.1 and 31.5–299.8 µg mL−1 after 24 and 48 h, respectively. Extracts with the best nematicidal potential (EC50,48h < 113 µg mL−1) were those from Adenophyllum aurantium, Alloispermum integrifolium, and Tournefortia densiflora, which inhibited L. esculentum seed growth by 100% at 20 µg mL−1. Stigmasterol (1), β-sitosterol (2), and α-terthienyl (3) were identified from A. aurantium, while 1, 2, lutein (4), centaurin (5), patuletin-7-β-O-glucoside (6), pendulin (7), and penduletin (8) were identified from A. integrifolium. From T. densiflora extract, allantoin (9), 9-O-angeloyl-retronecine (10), and its N-oxide (11) were identified. The present research is the first to report the effect of T. densiflora, A. integrifolium, and A. aurantium against N. aberrans and chemically characterized nematicidal extracts that may provide alternative sources of botanical nematicides.

Phytochemical Screening and Evaluation of Pesticidal Efficacy in the Oleoresins of Globba sessiliflora Sims and In Silico Study

“…In addition, the lipid, chitin, vitelline layers (which are primarily formed of glycoproteins), and uterine layers that make up the nematode eggshell's multilayered, robust barrier create a selective permeability that allows the applied chemical to pass through the egg [ 50 ]. Several hypotheses have been advanced to explain the nematicidal effects of plant extracts, including breakdown of cell membrane permeability and disruption of its functions, irreversible alterations of protein structures from the nematode surface caused by aldehydes, inhibition of acetylcholinesterase with neurotransmitter build-up in the nematode's central nervous system, followed by convulsion, paralysis, and death [ 51 , 52 ]. On the basis of the results obtained in the present study, we can say that the reduction of the egg hatching process and high mortality of J 2 of M. incognita may be associated with the chemical composition of the oleoresins (GSAO and GSRO).…”

Natural nematicidal metabolites and advances in their biocontrol capacity on plant parasitic nematodes

“…109 Allantoin 261 was isolated from Adenophyllum aurantium and exhibited nematicidal activity against N. aberrans . 48 An indoloditerpenoid, gymnoascole acetate 262 , was obtained from Gymnoascus reessii za-30 and induced 100% paralysis of M. incognita at 36 μg mL −1 for 24 h (EC 50 = 47.5 μg mL −1 ). 110 Ketamine 263 was the major nematicidal constituent isolated from the nematophagous fungus Pochonia chlamydosporia , and it exhibited activity against C. elegans .…”

Sustainable strategies for management of the “false root-knot nematode” Nacobbus spp.

“…Nematicidal and nematostatic activity of methanolic extracts of endemic plants from the Oaxaca state (Mexico) were also studied at different doses ( Velasco-Azorsa et al., 2021 ) and their effective concentrations (EC, 50% J2 immobility) were estimated. At 48 h, extracts of Adenophyllum aurantium (root: EC 50 = 62.3-88.3 µg/mL; stem: EC 50 = 31.5-110.4 µg/mL), Alloispermum integrifolium (EC 50 = 47.4-107.1 µg/mL) and Tournefortia densiflora (root: EC 50 = 59-112.3 µg/mL) showed the highest nematostatic potential on J2 of N. aberrans s.l.…”