Antibacterial properties and chemical characterization of the essential oils from summer savory extracted by microwave-assisted hydrodistillation

Hydrodistillation of the fresh leaves of E.grandis×E.urophylla hybrids and pure species E.grandis, E.urophylla, E.pellita, E.camaldulensis, E. dunni, and E.saligna collected from the trees grown in Guangxi Huangmian Forest (China), afforded essential oils in yields varying from 0.24±0.15% to 5.36±0.28%, according to the species. Analysis by GC (FID) and GC/MS allowed the identification of 67 compounds, representing 82.55% to 91.03% of the total oil composition. The dominant compounds were 1,8-cineole in E.saligna, E.urophylla, E.grandis×E.urophylla, E.grandis, E.pellita and E. dunni (67.48, 57.12, 48.21, 23.64, 20.34, 20.22%), p-Cymene in E.camaldulensis,E. dunni and E.grandis(21.32, 14.74, 13.38%), α-pinene in E.grandis and E.grandis×E.urophylla (21.77, 15.55%), α-terpinene in E. dunni and E.grandis (17.96, 9.35%), α-terpineol in E.pellita and E.saligna (19.24,11.54%), respectively. Hierarchical Cluster Analysis separated the characterized essential oils into two groups, each constituting a chemotype. E.grandis×E.urophylla and E.urophylla were classified in the same group, while E.grandis in the other.

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CHEMICAL CHARACTERIZATION OF BARK COMPOUNDS FROM CAATINGA SPECIES

FLORESTA ◽

10.5380/rf.v51i4.73967 ◽

2021 ◽

Vol 51 (4) ◽

pp. 893

Author(s):

Thiago Cardoso Silva ◽

Rafael Leite Braz ◽

Emmanoella Costa Guaraná Araujo ◽

Gisely Alves da Silva ◽

Maria de Los Angeles Perez Fernandez Palha

Keyword(s):

Essential Oils ◽

Near Infrared ◽

Chemical Characterization ◽

Hydroxyl Group ◽

Soluble Extract ◽

Total Extract ◽

Extract Content ◽

Total Extractives ◽

Water Alcohol

This study aimed to chemically characterize the bark extracts from three tree species: Anacardium occidentale L., Ziziphus joazeiro Mart. and Mimosa caesalpiniaefolia Benth., in addition to obtaining the soluble extract content in water, alcohol and hexane from the bark of these species. The bark was collected from branches of the three species and subsequently pre-dried and milled. The extract content was then determined using the Sohxlet method aiming to quantify the total extractives in the samples, and determine the extract content soluble in water, ethyl alcohol and hexane. The extracts were further analyzed by Near Infrared Spectroscopy (NIRS) analysis to determine their chemical composition. The extract contents in the three species behaved in a similar way, with hexane being the solvent which extracted more compounds and juazeiro the species that displayed the highest total extract content. With the chemical characterization of the extracts, it was possible to identify the presence of functional groups characteristic of carbohydrates and proteins in the aqueous extracts; the presence of characteristic hydroxyl group, for example in alcohols, aldehydes, ketones and ethers in the ethanolic extracts; and the presence of fatty acids and aromatic compounds (essential oils) in hexanolic extracts. The essential oils were the compounds which presented larger quantities, and can be exploited by the pharmaco-chemical industry.

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