Context GC-MS analysis is the best way to characterize volatile sulphur-containing compounds. Ferula (Apiaceae) is a genus of perennial herbs. Due to the occurrence of essential oils or oleoresins in the Ferula species, these plants usually possess strong aromatic scent. Terpenoid compounds were the most abundant constituents of Ferula oils, however, in some of Ferula species, the essential oils were dominated by volatile sulphur-containing compounds. Objectives Ferula alliacea Boiss. is considered one of the sources of the oleo-gum-resin asafoetida. In this study, we analyzed the hydrodistilled essential oil from its dried roots and provide new data about retention indices and mass fragmentation patterns of some volatile sulphur-containing compounds that are useful for future studies on this class of compounds. Materials and methods The roots of F. alliacea were collected during the flowering stage of plant, from Bezgh, Kashmar to Neishabour road, Khorasan-Razavi province, Iran, in June 2012. The oil was obtained by hydrodistillation using a Clevenger apparatus and analyzed by GC-MS. Results This is the first report on phytochemical analysis of F. alliacea roots. Seventy-six components, representing 99.5% of the oil, were characterized. The major components were 10-epi-γ-eudesmol (22.3%), valerianol (12.5%), hinesol (8.3%), guaiol (7.3%) and Z-propenyl-sec-butyl trisulphide (6.5%). Predominant mass fragment ions of the identified sulphur-containing compounds are explained in this paper. Conclusion The volatile oil of F. alliacea mostly contains oxygenated sesquiterpenes, however, its odour was dominated by sulphur-containing compounds. The most abundant sulphur-containing compound includes Z-propenyl-sec-butyl trisulphide (6.5%).
Keywords: Apiaceae; mintsulphide; oleo-gum-resin asafoetida; oxygenated sesquiterpenes
Ferula (Apiaceae), a genus of perennial herbs, comprises about 170 species distributed from central Asia (particularly Iran and Afghanistan) westward throughout the Mediterranean region to northern Africa (Pimenov & Leonov [
The most important medicinal Ferula species include F. assa-foetida Boiss. & Buhse, F. gummosa Boiss. F. foetida Regel, F. latisecta Rech. f. & Aellen and F. persica Willd. Previous research also unveiled a number of medicinal properties form Ferula spp. including antibacterial, antifungal, antioxidant, anti-inflammatory, antinociceptive, anticonvulsant, antispasmodic and hypotensive activities (Bakkali et al. [
Volatile sulphur compounds have been reported from different terrestrial plants (Iranshahi, [
Ferula alliacea Bioss. is used in Iranian folklore as one of asafoetida sources with similar medicinal applications to those of F. assa-foetida. This plant possessed a strong sulphurous odour due to the presence of volatile sulphur-containing compounds. No phytochemical investigation has been conducted on the volatile sulphur compounds of this species. In this study, we aimed to identify chemical composition of the essential oil of F. alliacea roots for the first time. The spectral mass fragmentation patterns of sulphur-containing compounds are also discussed in this paper. These mass fragmentation patterns can provide useful information for researchers who are interested in identifying the volatile sulphur-containing compounds of this genus.
The roots of F. alliacea were collected during the flowering stage of plant, from Bezgh, Kashmar to Neishabour road, Khorasan-Razavi province, Iran, in June 2012. The plant was identified by Mr. Joharchi and a voucher specimen (No. 38927) was deposited at the Herbarium of the Department of Pharmacognosy, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
Essential oil (EO) was isolated using hydro-distillation of air-dried material for 3 h, with a Clevenger-type apparatus. The oil was obtained as a greenish yellow liquid with a yield of 0.13% (v/w). The oil was dried over anhydrous sodium sulphate and stored at 4 °C in dark until use. The EO was dissolved in n-hexane for gas chromatography and mass spectrometry analyses.
The GC-MS analyses were performed using an Agilent 5975 apparatus (Agilent Technologies, Santa Clara, CA) with a HP-5 MS column (30 m × 0.25 mm i.d., 0.25 m film thicknesses) interfaced with a quadruple mass detector and a computer equipped with Wiley 7n. Library. Other analytical settings were: oven temperature: 50 °C (5 min), 50–250 °C (3 °C/min), 250 °C (10 min); injector temperature 250 °C; injection volume: 0.1 L; split ratio: 1:50; carrier gas: helium at 1.1 mL/min; ionization potential: 70 eV; ionization current: 150 A; and mass range: 35–465 mui. Identification of individual compounds was made by comparison of their mass spectra and retention indices (RI) with those of authentic samples and those given in the literature (Khajeh et al. [
The oil of the roots of Ferula alliacea was greenish yellow, in a total yield of 0.13% v/w. Seventy-six components were identified from the oil of this species (Table 1), representing 99.5% of the total oil. GC-MS analysis of the essential oil of F. alliacea roots led to the identification of mono- and sesquiterpenes as well as volatile sulphur-containing compounds. Although oxygenated sesquiterpenes were determined to be the most abundant constituents in the essential oil, the odour of the oil was dominated by volatile sulphur-containing compounds. The essential oil contained oxygenated sesquiterpenes (74.7%), sulphur-containing compounds (16.6%), sesquiterpene hydrocarbons (3.7%) and oxygenated monoterpenes (2.6%). The major components of the oil were determined to be 10-epi-γ-eudesmol (22.3%), valerianol (12.5%), hinesol (8.3%), guaiol (7.3%) and Z-propenyl-sec-butyl trisulphide (6.5%). The sulphur-containing compounds (16.6% of the oil, Table 2) were identified to be 3,4-dimethyl thiophene (trace), 2,3,4-trimethyl thiophene (trace), propyl sec-butyl disulphide (0.1%), Z-1-propenyl sec-butyl disulphide (2.2%), E-1-propenyl sec-butyl disulphide (1.9%), di-sec-butyl disulphide (0.1%), methyl 1-(methylthio) propyl disulphide (0.1%), Z-1-propenyl propyl trisulphide (0.3%), E-1-propenyl propyl trisulphide (0.4%), Z-1-propenyl sec-butyl trisulphide (6.5%), E-1-propenyl sec-butyl trisulphide (2.7%), sec-butenyl sec-butyl trisulphide (0.1%) and mintsulphide (0.3%). The volatile sulphur-containing compounds were characterized on the basis of their retention indices (Iranshahi [
Graph: Figure 1. Major mass fragmentation ions of the volatile sulphur-containing compounds from Ferula alliacea.
Table 1. Chemical composition of the essential oil from the roots of Ferula alliacea Boiss.
NO Compound RI Percentage 1 3,4-Dimethyl thiophene 905 2 Methyl 994 3 2,3,4-Trimethyl thiophene 1015 0.1 4 1149 5 1167 0.1 6 Borneol 1169 0.1 7 1171 2.2 8 Lavandulol 1174 0.1 9 1176 1.9 10 1203 0.5 11 di- 1214 0.1 12 1224 0.1 13 Nerol 1234 0.1 14 Carvone 1248 15 Methyl-1-(methylthio) propyl disulphide 1259 0.1 16 Bornyl acetate 1290 0.1 17 Lavandulyl acetate 1297 0.3 18 1303 19 Terpinen-4-ol acetate 1306 0.3 20 δ-Terpenyl acetate 1328 0.8 21 1349 0.3 22 1353 0.3 23 Neryl acetate 1373 0.1 24 α-Copaene 1379 0.1 25 1393 0.4 26 β-Elemene 1395 0.3 27 β-Funebrene 1415 0.1 28 1422 0.2 29 Z-Propenyl- 1433 6.5 30 1435 2.7 31 β-Barbatene 1445 0.2 32 α-Humulene 1457 0.2 33 1461 0.1 34 β-Farnesene 1465 0.1 35 Inseparable mixture of 1473 1.0 36 γ-Murrolene 1481 0.2 37 α-Amorphene 1484 38 β-Chamigrene 1487 0.1 39 β-Selinene 1489 0.3 40 δ-Selinene 1496 0.2 41 Bicyclogermacrene 1499 0.5 42 β-Himachalene 1502 0.8 43 β-Dihydroagarofurane 1506 0.3 44 Cuparene 1509 0.3 45 1511 0.1 46 ( 1515 0.2 47 Butylated hydroxy toluene 1519 0.6 48 Myristicin 1528 0.7 49 α-Agarofuran 1549 1.2 50 Elemol 1555 0.8 51 Elemicin 1565 0.4 52 1572 0.2 53 Spathulenol 1582 0.3 54 Viridiflorol 1595 0.2 55 Guaiol 1606 7.3 56 5- 1615 4.7 57 10- 1630 22.3 58 γ-Eudesmol 1632 0.2 59 Eremoligenol 1638 2.0 60 Hinesol 1645 8.3 61 Agarospirol 1647 0.9 62 α-Eudesmol 1658 3.6 63 Valerianol 1663 12.5 64 7- 1666 2.4 65 (2 1680 2.3 66 α- 1691 0.1 67 α-Bisabolol 1693 0.4 68 Inseparable mixture of 1699 0.4 69 (2 1707 0.2 70 Mintsulphide 1741 0.3 71 Unknown 1749 0.2 72 Cedryl acetate 1768 0.4 73 Hinesol acetate 1784 1.4 74 α-Eudesmol acetate 1793 0.9 75 (2 1800 1.8 76 Unknown 1822 0.3 Monoterpene hydrocarbons 0 Oxygenated monoterpenes 2.6 Sesquiterpene hydrocarbons 3.9 Oxygenated sesquiterpenes 74.7 Sulphur-containing compounds 16.6 Miscellaneous compounds 1.7 Total identified 99.5
1
- 2
b t: trace > 0.05%. - 3
c For the RIs of sulphur-containing compounds, see Iranshahy and Iranshahi ([20 ]), Sahebkar et al. ([28 ]), and Sahebkar and Iranshahi ([29 ]).
Table 2. Mass fragmentation ions observed for volatile sulphur-containing compounds from the essential oil of Ferula alliacea roots. Predominant ions have shown in bold.
No. Compound name Mass fragmentation ions (percentage) 1 3,4-Dimethyl thiophene 2 Methyl 3 2,3,4-Trimethyl thiophene 5 7 9 11 di- 15 Methyl 1-(methylthio) propyl disulphide 21 180 (3), 22 180 (3), 25 n-Propyl 194 (3), 29 194 (1), 30 194 (1), 35 Inseparable mixture of 45 208 (1), 68 Inseparable mixture of 70 Mintsulphide 236 (25), 159 (9),
In general, sec-butyl part of sulphur-containing compounds is considered as the chemotaxonomic marker of the family Apiaceae. sec-Butyl derivatives of sulphur-containing compounds have previously been reported from Ferula species including F. assa-foetida (Iranshahy & Iranshahi [
In total, GC-MS analysis is the best approach to characterize sulphur-containing compounds. The characterization of these compounds is not commonly carried out using NMR techniques due but their small quantities and volatility. In this study, we tried to provide new information about the retention indices and mass fragmentation patterns of some volatile sulphur-containing compounds that are useful for future studies on this class of compounds.
The volatile oil of F. alliacea mostly contains oxygenated sesquiterpenes, however, its odour was dominated by sulphur-containing compounds. The most abundant sulphur-containing compound includes Z-propenyl-sec-butyl trisulphide (6.5%).
This plant is used by local people as an anthelminthic and antispasmodic herb for gastrointestinal disorders. There is a gap in our knowledge about the biological activities of sulphur components of F. alliacea and other Ferula species that needs further investigation; however, sulphur compounds may play a role, at least in part, in biological activities of this plant.
The authors would like to thank Mr. H. Joharchi for his assistance in plant identification.
The authors report no declarations of interest.
This research was supported by Mashhad University of Medical Sciences (MUMS) Research Council.
By Jamal Kasaian; Javad Asili and Mehrdad Iranshahi
Reported by Author; Author; Author