Seasonal and Circadian Evaluation of the Pectis brevipedunculata Essential Oil and Its Acaricidal Activity against Rhipicephalus microplus (Acari: Ixodidae)

Abstract

Pectis brevipedunculata are native species and widely available in dry and semi-arid ecosystems showing high biotechnological potential. The objective of this study was to evaluate the circadian and seasonal chemical variation of the essential oil (EO) of P. brevipedunculata, as well as its acaricide effect on Rhipicephalus microplus larvae. Aerial parts were collected and submitted to the hydrodistillation process, and the chemical composition was determined by gas chromatography mass spectrometry (GC-MS). For the assays with R. microplus, the larval immersion test was performed. The main constituents were citral (75% of the EO), followed by α-pinene and limonene. In the seasonality analysis, the highest yields were in the months of April (2.08%) and August (2.05%), while in the study of circadian rhythm, the percentage was 2.0% at 6 p.m. in the rainy season, and 1.2%, dry season at 6 p.m. Concerning acaricidal activity (50% lethal concentration (LC50)), the April (1.17 mg mL-1), March (1.28 mg mL-1), June (1.37 mg mL-1), and October (1.27 mg mL-1) oils obtained were the most active and assays performed with circadian rhythm revealed in the rain season (April) at 6 p.m. and dry season (September) at 12 a.m. LC50 values of 1.75 and 1.75 mg mL-1, respectively. Additionally, this EO is selective to non-target organisms, i.e., ladybeetles and lacewing.

Chemical Characterization, Leishmanicidal Activity and In Vitro Cytotoxicity of the Essential Oil Extracted from Pectis brevipedunculata (Gardner) Sch.Bip. and Its Incorporation into Microemulsion Systems

“…The EO-PB yield extracted from 300 g of aerial P. brevipedunculata parts was 0.67%; this percentage was higher compared to specimens reported in other studies, such as aerial parts like leaves, branches, flowers and seeds (0.17%) [ 34 ], as well as the EO obtained from leaves and floral portions (0.36%) [ 6 ]. A seasonal study of the EO extracted from P. brevipedunculata reported higher contents in January and May (2.1%) and lower in February and September (1.1%) [ 7 ].…”

“…This may be due to natural volatilization during long drying times at room temperature, generating EO constituent losses and degradation [6]. A recent study on the seasonal and circadian evaluation of the P. brevipedunculata EO extracted by hydrodistillation revealed citral (neral and geranial) percentages ranging between 49.8 and 76.4%, followed by α-pinene (7.2% to 19.8%) and limonene (5.3% to 9.4%), both present at lower concentrations [7]. The literature, however, reports that citral concentrations and the volatile profile of P. brevipedunculata may vary depending on the EO extraction method [32].…”

“…Regarding its chemical composition, the major P. brevipedunculata essential oil (EO) components are geranial and neral, which, together, represent about 51% of the plant’s in natura oil. The third most prevalent component is α-pinene, ranging from 17 to 30%, followed by limonene, from 7 to 14% [ 6 , 7 ].…”

Effects of Piper aduncum (Piperales: Piperaceae) Essential Oil and Its Main Component Dillapiole on Detoxifying Enzymes and Acetylcholinesterase Activity of Amblyomma sculptum (Acari: Ixodidae)

“…The need to perform biological activity tests with the major compound(s) found in the chromatographic analysis of an EO is necessary due to two main reasons: the first is that EOs can exhibit variations in their compound composition due to varying environmental conditions, soil composition, growth stages, biotic factors, and genetic diversity within the plant [35][36][37][38]. The second reason is that EOs are complex mixtures of monoterpenes, sesquiterpenes, and phenylpropanoids, and the primary components can interact synergistically or antagonistically with minor constituents, thereby producing results that differ from what might be expected for individual compounds [39].…”

Contributions of γ-Aminobutyric Acid (GABA) Receptors for the Activities of Pectis brevipedunculata Essential Oil against Drosophila suzukii and Pollinator Bees

“…Bip. It is a small plant, rich in secondary metabolites, and native to dry and rocky environments [4,5]. The essential oil of P. brevipedunculata is mainly composed of citral, α-pinene, and limonene [4,6], which have antimicrobial, antioxidant, anti-inflammatory, and antidepressant potential [7][8][9][10].…”