Valorization of the essential oil from Drypetes gossweileri S. Moore (Putranjivaceae): in vitro, in vivo , and in silico nematicidal activity

• Published in: Frontiers in plant science 2023-11, Vol.14, p.1260360-1260360
• Main Authors: Mbula, Jean Pierre, Andres, Maria Fe, Kitete, Emmanuel M, Kasiama, N G, Tshilanda, D D, Ngbolua, K N, Tshibangu, D S T, Onautshu, O, González-Coloma, Azucena, Mpiana, Pius T
• Format: Article
• Language: English
• Subjects: Drypetes gossweileri; essential oil; insect antifeedant; molecular docking; nematicidal activity; phytotoxic; Plant Science
• ISSN: 1664-462X; 1664-462X
• DOI: 10.3389/fpls.2023.1260360

The chemical composition, insect antifeedant, nematicidal activity, phytotoxicity, and nematicidal activity of the essential oil (EO) of the African medicinal plant were studied. Chemical analysis using GC/MS indicated that benzyl isothiocyanate (96.23%) was the major compound, followed by benzyl cyanide (1.38%). The biocidal effects of this oil were tested against insect pests and root-knot nematodes. All the insect species tested were significantly affected by the oil according to their feeding adaptations ( and were less affected than ) with efficient doses (EC ) of 29.4 8.3 μg/cm , 14.744 8.3 μg/cm , and 8.3 μg/cm , respectively. The oil was highly effective against juveniles J2 of the nematode , with LC -LC values of 0.007 mg/mL-0.0113 mg/mL. EO at minimum lethal concentrations (MLC) and below strongly inhibited egg hatching , whereas soil treatment caused a strong suppression of nematode population, infection frequency, and multiplication rate. The EO inhibited ryegrass ( ) germination at 0.4 mg/mL, while at 0.1 mg/mL, its effects on germination, root and leaf growth were moderate (32.4%, 8.4%, and 18.3%, respectively). The tomato ( ) germination was not affected by the EO, but the root growth was reduced (56% at 0.1 mg/mL) at a dose 10 times higher than the LD calculated for J2 mortality. Molecular docking of the nematicidal effects of the oil using PyRx revealed a strong interaction between potassium chloride transporting KCC3 (PDB ID: 7D90) and benzyl cyanide at a distance of 2.20 A° with GLN C:350, followed by benzyl isothiocyanate at a distance of 2.78 A° with ARG B:294. The nematicidal effects of EO on penetration and reproduction in tomato roots further support the potential of this EO as a nematicidal agent with insect antifeedant effects, which could be used by local farmers for crop protection.