Composition of Essential Oil from Bunium incrassatum from Algeria

Abstract

The flora of Algeria includes seven species of the plant genus Bunium, four of which are endemic [1]. Essential oils from Bunium species were studied several times [2–6]. The root extract of B. incrassatum afforded two coumarins, -sitosterol, sucrose, and oleic acid. The antimicrobial activity of the primary extract was assessed using agar diffusion. The results showed that the primary extract had highly promising antimicrobial activity against all test microorganisms, especially against fungal strains [7]. Table 1 presents the chemical composition of oils obtained from other Bunium species. B. persicum (Siyah zira, black cumin) is used in Central Asia, Iran, Afghanistan, and Pakistan as a caraway substitute [4–6]. However, information about the essential-oil composition of B. incrassatum has not been published. Essential oils from steam distillation of B. incrassatum collected in Souk Naamane district (eastern Algeria) were analyzed using GC and GC/MS. Table 1 presents the essential-oil composition. Oil from ground fruit (A) of B. incrassatum afforded 28 components (81.4%) including caryophyllene oxide (31.0%), (Z)-farnesene (8.7), -caryophyllene (7.2), and germacrene B (5.8) as the principal constituents of sample A. Oil from fruit-bearing branches (B) of B. incrassatum held 40 constituents (85.2%) including caryophyllene oxide (26.8%), nonacosane (11.6), germacrene B (7.7), -caryophyllene (5.8), (Z)-farnesene (5.1), caryophyllenol II (4.8), and spathulenol (2.5) as the principal constituents in sample B. Thickened branches (C) of B. incrassatum yielded 24 constituents (75.4%) including nonacosane (44.7%), spathulenol (5.3), eudesm-4(15),7-dien-1 -ol (4.4), caryophyllenol II (4.1), (Z)-farnesene (2.3), germacrene B (1.2), and -caryophyllene (1.0) as the principal constituents of sample C. Plant Material. Ground fruit, fruit-bearing branches, and thickened branches of B. incrassatum Batt. (Apiaceae) were collected in Souk Naamane district in Oum-El-Buoaghi province (eastern Algeria) in May 2012. The plant was defined by Dr. Amar Zellagui, instructor of the Department of Biology, University of Oum-El-Bouaghi. A control specimen is preserved in the herbarium of the Department of Biology at the university (Constantine city) under code number ZA 103. Essential Oil Production. Ground fruit and fruit-bearing and thickened branches were steam distilled for 3 h using a Clevenger apparatus in order to determine the percent contents and traces. GC and GC/MS Conditions. GC used an Agilent 6890N chromatograph. The FID temperature was 300°C. A duplicate auto-injection onto an identical column using identical working conditions was made in order to obtain the identical elution sequence for GC/MS analysis. GC/MS used an Agilent 5975 GC-MSD, an Innowax FSC column (60 m 0.25 mm, film thickness 0.25 mm), and He carrier gas (0.8 mL/min). The GC furnace temperature was maintained at 60°C for 10 min, programmed to 220°C at 4°C/min, held at 220°C for 10 min, and then programmed to 240°C at 1°C/min. The flow division was set at 40:1. The injector temperature was 250°C. The ionizing-electron energy was 70 eV. The m/z range was 35–450. Essential oil constituents were identified by comparing their relative retention times with those of authentic samples or by comparing their relative retention indices (RRI) with a series of n-alkanes. The identification used computerized matching with commercial (Wiley GC/MS Library, Adams Library, MassFinder 3 Library) and local (Bayer Library of Essential Oil Constituents) databases that were created using information for authentic compositions and known oil constituents in addition to MS data from the literature.