Alternative Biodefensive based on the Essential Oil from Allium sativum Encapsulated in PCL/Gelatin Nanoparticles

The goal of this paper was to develop a biodegradable system containing the essential oil from Allium sativum bulbs encapsulated in PCL/gelatin-based nanoparticles, as well as evaluate its efficiency to control Aedes aegypti Linn. larvae and Cerataphis lataniae Bois. aphids. The essential oil was analyzed by GC-FID and GC-MS, and six compounds were identified, representing 93.1% of the total oil. The major compounds were diallyl trisulfide (51.8%), diallyl disulfide (23.2%) and allyl methyl trisulfide (13.6%). The PCL/gelatin-based nanoparticles containing this essential oil exhibited encapsulation efficiency higher than 94%, average particle diameter around 200 nm and zeta potential values about -36 mV. The essential oil presented no antioxidant nor enzymatic activities, so its effectiveness might be explained by the presence of sulfur compounds. The release kinetics of the encapsulated essential oil confirmed the release mechanism by the Fick's Law. About 50% of the encapsulated essential oil was released after 1 h, and about 90% was released after 50 h. This behavior is interesting from the technological point of view since the nanoparticles released as much oil as possible in a short period of time and then the lethal dosages were maintained along the time. Nanoparticles containing the encapsulated essential oil was submitted to in vitro bioassays against A. aegypti and C. lataniae and showed 100% of mortality against larvae and aphids up to 24 h. In conclusion, the essential oil from A. sativum presented effectiveness to be applied in sustainable management of pests in greenhouses, as well as for larvicidal control

Bioactivity of Licaria puchury-major Essential Oil Against Aedes aegypti , Tetranychus urticae and Cerataphis lataniae

The present study was carried out to evaluate an alternative controlling agent for greenhouse pests and the yellow fever mosquito larvae. The potential bioactivity of Licaria puchury-major (Mart.) Kosterm. (“puxuri”) was evaluated here against three most common pests in tropical and subtropical countries: Aedes aegypti Linn. Larvae, Tetranychus urticae Koch. mites and Cerataphis lataniae Boisd. aphids. The essential oil from seeds was analyzed by GC-FID and GC-MS. The major compounds were safrole (38.8%) and eucalyptol (21.7%). Phenylpropanes (51.7%) was the main group of compounds and oxygenated monoterpenes represented 28.8% of the total oil. The essential oil has shown no inhibition of acetylcholinesterase (AChE) in the tested concentrations. However, potential antioxidant activities were evaluated by different methods [DPPH: LD 50 = (27.8 ± 1.0) µg/.mL; ABTS: (977.3 ± 25.2) µM TEs/g (Trolox Equivalents); FRAP: (548.2 ± 29.0) µM Fe(II)/g]. A significant larvicidal potential for 24 h of exposure was observed with LD 50 = 98.9 µg/mL, being an indicative that the larval mortality may occur by ingestion or contact due to the no inhibition against AChE. Volatile phase effects were evaluated against T. urticae Koch. and C. lataniae Boisd. and LD 50 were found about 30.8 and 13.5 µg/mL , respectively. These results are consistent with an octopaminergic effect , since some phenylpropanoids (such as Safrole, identified as the major compound in this work) can block octopamine, a multi-functional, naturally occurring biogenic amine. Then, this study clearly illustrated the efficacy of the investigated seeds, which encourages the development of a new potential natural controlling agent against these common pests due to the abundance of these seeds in the Amazon region and to the high essential oil yield

Theoretical Investigation of the Structural, Spectroscopic, Electronic, and Pharmacological Properties of 4-Nerolidylcathecol, an Important Bioactive Molecule

4-Nerolidylcatechol (4NRC), a secondary metabolite described as a potent antioxidant that presents anti-inflammatory, antimalarial, analgesic, and cytotoxic properties, has been receiving prominence in the catechol class. In this work, a theoretical DFT study of the vibrational, structural, and quantum properties of 4-nerolidylcatechol (4NRC) using the B3LYP/6-311G (2d,p) level is presented. The theoretical molecular geometry data were compared with the X-ray data of a similar molecule in the associated literature and a conformational study is presented, with the aim of providing a good comprehension of the 4NRC structural arrangement and stability. Also, HOMO-LUMO energy gap and natural bond orbitals (NBOs) were performed and discussed. The calculated UV spectrum showed similarity to the experimentally obtained data, with transitions assigned. The comparative IR studies revealed that intermolecular hydrogen bonds that stabilize dimeric forms are plausible and also allowed the assignment of several characteristic vibrations. Molecular docking calculations with DNA topoisomerase I-DNA complex (TOPO-I), glyceraldehyde 3-phospate dehydrogenase (GAPDH), and Plasmodium falciparum lactate dehydrogenase (PfLDH) showed binding free energies of −6.3, −6.5, and −7.6 kcal/mol, respectively, which indicates that 4NRC is a good competitive inhibitor for these enzymes