Abstract. The volatile oil compusition of 23 Iranian basil (Oc/mum basilicum L.) accessions was studied for chemotaxonnmlc identification using headspace sotld ...
Profiling Volatile Oil Compounds Using HS-SPMF., GC-MS Detection, a Fast and ReJiable Tool for Classification of Basil (Oclmum basilicum L.) Accessions 1. Javanrnardi Department of Ilorticulturc, College of Agriculture, Shiraz University, Shiraz Iran Keywords: Ocimum basilicum 1.., volatile oil, cbemotypcs,
HS
SPME. GC-MS
Abstract The volatile oil compusition of 23 Iranian basil (Oc/mum basilicum L.) accessions was studied for chemotaxonnmlc identification using headspace sotldphase microextractiun coupled with gas chromatography - mass spectrometry analysis (JiS-SPME, GC-MS). Cluster analysis ef accessions based on three major aroma components, IIn81oo1, metbylchavicol and cltral, showed two main groups "Citral-containing" and "Nnn-Citral-cuntaining" with five distinctive chcmotype suhgroups: cltral; methylchavicollcitrul; mcthylchavicoI/IiOillooJ/citral; methylchavirol and merhylchavlcoi/linaleul, Statistical analysis shewed a direct corretation between the appearance (If linalool, methylchavicol and the purple color in leaf, stem or flower tissues that represents the presence of anthocyan ins. I~TRODUCTION Hcadspace solid-phase micro extraction (HS-SPME) represents a reliable method for the screening of simple but also very complex mixtures of organic volatiles (Rohloff, 1999). Also, the absorptive nature of the fibrous matrix permits assays at nondestructive temperatures (Beaulieu and Grimm, 20(1). This technique hus been successfully used fill' the analysis of volatile flavor compounds (Sostaric ct al., 2(00). The volatile oils of O. busilicum are used as 1'000 flavorings. dental products. fragrances, and in traditional rituals and medicines (Simon ct al., 19X4). It has been shown that the chemical profile of secondary metabolites such us volatile uils and flavonoids is a useful indicator of taxonomic relationship at the intraspecific and infravarietal levels and can be a complement to a profile of morphological features (Vieira, 19l)(). The richness and diversity of aromatic compounds in unusual O. basilicum varieties in Iran led us to examine Iranian basil accessions for variation in volatile oil metabolites using HS-SPME with GC-\-1S detection to classify Iranian hasils chernotaxonomically based on the profile of volatile oils. MATERIALS
AND METHODS
Plant Material Seeds of' 23 accessions of basil «()cinrum basilicum L.) were collected from small farmers and home gardens iJ1 Iran and were grown to flowering stage (Table 1). This collection represents most of the traditional basil plants used tor culinary and medicinal purposes in Iran, The above ground biomass or each plant was harvested 01 full bloom, weighed, bulked and dried in a paper bag with a forced air drier at 32°(' for 15 days. SPME, GC-MS Samples A polydimethylsiloxanc (POMS) coated fiber (I 00 um) and a manual SPME holder were used for sample extraction. One gram of each sample was ground and scaled in a HI ml screw-lop vial and placed in a drying cabinet at 50"C fur 50 min followed by exposing SPME fiber tor 10 min. Then SPME fiber was inserted into the injection port or the (jC fur 4() min for sample desorption. The active compounds from both volatile oil samples and SPME sampling were identified by a mass spectrum database search (Varian NIST MS database 1992 and IMS Terpene Library, 1992) and on the basis olthc relative Proc. I" It: on Culinary llerbs Eds.: K. Turgut ct al. 1\,13 Hon, 82(l, lSI IS 20()9
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retention index (ESO 2000, Database of E!.senlial Oils. UACIS 20(0). Quantitative analysis was performed by peak area normalization measurements using Total Ion Count (TIC).
RES\;LTS AND DISCliSSION Chemical Characterization Twenty-nine compounds. representing -90% of the GC profile. were rnonoicrpcncs. scsquiterpencs and several aromatic compounds such as citral, eugenol, linalool and methylchavicol. Three major components of volatile oils. linalool, mcthylchavicol and citral, were considered for cluster analysis to identity the possible chemotypes. The resulting dendrogram showed the existence of two main groups consisting "Citral-containing" and "Non-Citral-containing" chcmotypes which all made five distinct subgroup clusters (Fig. I). Correlation between Anthocyanin and Linalool, Methylchavicol Comparing the results of horticultural traits (Javanmardi ct al., 20()2) and (jC-~S chromatograms of HS-SPME volatile oil compositions, showed that there is a direct correlation between the existence of linalool, mcthylchuvicul the aromatic compounds, and the presence or anthocyan ins. While it is not always possible 10 establish a strict correlation between morphological characteristics and chemotypc, in few cases some correlations seem evident (Marotti ct al., J 996). On the basis or our results, it is dear thal there is probably a regulation effect between the synthesis anthocyanins and linalool, methylchavicol. The same condition of regulatory cncct has been shown between linalool and other pigments such as carotenoids (Giuliano ct al., 1993). According to these results it can be concluded that the purple color, which is the cause of anthocyanins' existence, can be used as a morphological marker for the presence oflinalool and mcthylchavicol.
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Literature Cited Beaulieu. J.e. and Grimm. e.C. 200 I. Identification of volatile compounds in cantaloupe at various developmental stages using solid phase microcxtraction. J. Agric. Food Chern. 49 (3): 1345 - 1352. Giuliano. 0., Bartley, G.F.. and Scolnik, P.A. 1
