Seasonal changes in the essential oils of Aloysia oblanceolata Moldenke

Paulo Vinicius L Santos; Mateus Machado Lima; Flavia Cristina A Lucas; Joyce Kelly do R da Silva; José Guilherme S Maia; Pablo Luis B Figueiredo

doi:10.3389/fchem.2025.1564404

Seasonal changes in the essential oils of Aloysia oblanceolata Moldenke

Front Chem. 2025 Jun 20:13:1564404. doi: 10.3389/fchem.2025.1564404. eCollection 2025.

Authors

Paulo Vinicius L Santos^{1

2}, Mateus Machado Lima², Flavia Cristina A Lucas³, Joyce Kelly do R da Silva⁴, José Guilherme S Maia¹, Pablo Luis B Figueiredo^{1

2

3}

Affiliations

¹ Programa de Pós-Graduação em Ciências Farmacêuticas, Instituto de Ciências da Saúde, Universidade Federal do Pará, Belém, Brazil.
² Laboratório de Química dos Produtos Naturais, Universidade do Estado Pará, Belém, Brazil.
³ Programa de Pós-Graduação em Ciências Ambientais, Universidade do Estado do Pará, Belém, Brazil.
⁴ Programa de Pós-Graduação em Biotecnologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Brazil.

Abstract

Introduction: Aromatic plant species that produce essential oils contain bioactive compounds and medicinal properties, and are thus used in traditional medicine. This study aims to analyze the seasonal variation in Aloysia oblanceolata Moldenke's essential oil's chemical composition in the Amazon region.

Methods: The botanical material was collected monthly over 1 year; the leaf essential oils were extracted by hydrodistillation, and their chemical composition was analyzed through gas chromatography-mass spectrometry (GC-MS). Local climatic parameters, such as insolation, temperature, relative humidity, and precipitation, were monitored. Multivariate statistical analyses were performed using hierarchical cluster analysis (HCA) and principal component analysis (PCA).

Results and discussion: The AoEO yields ranged from 3.4% (December 2022 and February 2023) to 5.3% (August and September 2023), with an average of 4.3% ± 0.7%. Essential oil yields did not show a significant difference (p > 0.05) between the dry (4.7% ± 0.7%) and rainy (4.1% ± 0.6%) periods. GC and GC-MS identified 38 chemical constituents in the essential oils, comprising approximately 94.6%-97.1% of the oils analyzed in the seasonal variation study over the 12-month period. The chemical constituents that significantly correlated with climatic factors were trans-pinocamphone, β-pinene, and E-caryophyllene. Group I was statistically different from Groups II and III in terms of trans-pinocarvyl acetate content (I = 7.0 ± 0.5%; II = 9.1 ± 0.3%; III = 8.2 ± 0.6%). Group II differed from the other groups in terms of its β-pinene (I = 4.3 ± 0.5%; II = 5.2 ± 0.3%; III = 1.6 ± 0.9%), trans-pinocamphone (I = 13.1 ± 1.2%; II = 15.9 ± 0.4%; III = 12.5 ± 2.1%), and E-caryophyllene contents (I = 6.9 ± 0.7%; II = 4.7 ± 0.1%; III = 7.9 ± 1.6%). Furthermore, Group III differed from the other groups in terms of β-pinene content (I = 4.3 ± 0.5%; II = 5.2 ± 0.3%; III = 1.6 ± 0.9%). These results indicate seasonal variations in the chemical composition of the essential oils, possibly influenced by environmental factors and plant development.

Keywords: Verbenaceae; environmental factors; essential oil composition; lavender; mono- and sesquiterpenes.