ARTICLE | doi:10.20944/preprints201909.0121.v1
Subject: Life Sciences, Biochemistry Keywords: Tomato borer; essential oil; GC-MS profile; larvicidal effects
Online: 11 September 2019 (13:21:03 CEST)
This study aimed to determine the Gas Chrommatography (GC)-Mass Spectrometry (MS) profiles and insecticidal activity of essential oils (EOs) from Thymus vulgaris (Thyme) and Cymbopogon citratus (Lemongrass) against the invasive and devastating pest, Tuta absoluta (T. absoluta) through contact and fumigation routes. We found out that thyme oil was predominantly constituted of Thymol (22.16%), α-Pinene (15.35%) and p-Cymene (13.54%) whilst Neral (21.41%), Geranial (21.36%) and β-Myrcene (9.74%) were the major constituents of lemongrass oil. Lemongrass oil exhibited higher insecticidal efficiency irrespective of application mode with 50% lethal dose (LD50) values of 35.8 and 72.2 µL.L-1air on contact and fumigation routes, respectively. Lemongrass oil also lengthened pupal duration at all tested doses irrespective of application routes. The overall responses of Lemongrass oil surpassed that of the reference insecticide (Lynx®: Lambda-cyhalothrine; Acetamipride). Thus, the recorded data clearly showed the acute and long-term insecticidal effects of the studied EOs, though a greenhouse and open field trials are required prior to the validation of this approach as remediation measure for Integrated Pest Management (IPM) for tomato borer control in Cameroon and elsewhere.
ARTICLE | doi:10.20944/preprints201810.0113.v1
Subject: Chemistry, Food Chemistry Keywords: Sea Squirts; Metabolites; GC-MS; Anti-bacterial; Zika vector; larvicidal
Online: 6 October 2018 (11:18:31 CEST)
In this present study, we conducted untargeted metabolic profiling using Gas Chromatography-Mass Spectrometry (GC-MS) analysis of ascidian Didemnum bistratum to assess the chemical constituents by searching in NIST library with promising biological properties against anti-bacterial and Zika virus vector mosquitocidal Properties. Metabolites, steroids and fatty acids are abundant in crude compounds of ascidian D. bistratum and showed potential zone growth inhibition against bacterial strains Kluyvera ascorbate (10 mm). The active crude compounds of D. bistratum exhibited prominent larvicidal activity against the Zika vector mosquitoes of Aedes aegypti and Cluex quinquefasciatus (LC50 values of 0.4436 to 2.23 mg/mL). The findings of this study provide a first evidence of the biological properties exhibited by D. bistratum extracts, thus increasing the knowledge about the Zika virus vector mosquitocidal properties of ascidian. Overall, ascidian D. bistratum are promising and biocontrol or eco-friendly tool against A. aegypti and C. quinquefasciatus with prospective toxicity against non-target organisms.