Abstract
Background:
Pycnocycla spinosa Decne. ex Boiss is an aromatic plant which showed relaxant effects on isolated ileum contractions and antidiarrheal activity. Thirty four components have been extracted from P. spinosa essential oil, of which several major constituents were found to show seasonal variation.Objectives:
The aim of this work is to evaluate the diurnal variation of its oil constituents during specific hours of the day.Materials and Methods:
The Pycnocycla spinosa samples were collected at different times of the day. The hydro-distilled aerial parts oils of collected P. spinosa were analyzed by GC and GC/MS.Results:
Fourteen monoterpenoid and nine sesquiterpenoid components were identified, of which the fluctuating constituents were p-cymene, trans-β-ocimene, β-citronellol, citronellyl pentanoate, geranyl isovalerate, α-humulene, caryophyllen oxide, α-cadinol, and α-eudesmol. The content of p-cymene in the essential oil in different daily times varied from 0.16 to 4.19%, and the geranyl isovalerate 7.75 -23.99%.Conclusions:
Essential oils with different qualities can be obtained according to the harvest time of the plant in a day.Keywords
1. Background
Pycnocycla spinosa Decne. ex Boiss is a variety of Pycnocycla which belongs to Umbelliferae. It is an aromatic plant distributed in central parts of Iran (1). It was reported that the essential oil and extract of P. spinosa have relaxant effects on isolated ileum contractions in relatively low concentration. The essential oil has more potent ileum relaxant effects than its extract (2, 3). In addition, comparative studies have been shown that the antidiarrheal activity of P. spinosa extract and its effect on small intestinal transition of charcoal meal are relatively similar to loperamide (4). The hydrodistilled aerial parts oil of Pycnocycla spinosa was analyzed and thirty-four components have been identified. The most abundant constituents identified in the essential oil are geranyl isopantanoate, caryophyllene oxide, β-eudesmol, citronellol, elemicin, p-cymene, citronellyl acetate, α-cadinol, nonadecane, sabinene, octanal, δ-candinene, methyl eugenol, decanal, trans-β-ocimene, limonene, trans-caryophyllene and octadecane respectively, of which several major constituents were found to show seasonal variation (5, 6). There are no data concerning the diurnal variation of these constituents during specific hours of the day. It is well known that the concentration of phytochemicals varies during the day. Diurnal variation in plant secondary chemical components has been observed, either related to light conditions (7, 8), water deficit (9) or more complex interactions (10). Diurnal cycles characterize the accumulation of many compounds in plants. This is an expression of changes in enzymatic activities in the daily courses; such variations are suggested to be probably caused by variations in temperature or light conditions. This paper reports the diurnal variation of the essential oil from aerial parts of the plant. There has been no research regarding this issue.
The amount of a compound is usually not constant throughout the life of a plant. The stage at which a plant is collected is, therefore, very important for maximizing the yield of the desired constituents. It is well known that the concentration of many metabolites in plants varies during the day and season (11-13). Diurnal fluctuations of the alkaloid concentration in the Lupinus spp have previously been explained (14). The yield and composition of the essential oil from the leaves of Eucalypt (Eucalyptus nicholii), Rosemary (Rosmarinus officinalis L.), White Cedar (Thuja occidentalis L.) and Lawson Cypress (Chamaecyparis lawsoniana) was reported to have diurnal variation (15). However, a limited published data is available for the role of the time harvesting on chemical composition of essential oil (16-24).
2. Objectives
The essential oils composition of Pycnocycla spinosa was found to show seasonal variation (6). There are no data concerning the diurnal variation of its oil constituents during specific hours of the day. In this study, the diurnal variation was investigated.
3. Materials and Methods
3.1. Plant Materials
Pycnocycla spinosa var. spinosa was collected from Isfahan University campus and was identified by the botanist Mr. Mehregan in department of biology at Isfahan University. A voucher specimen (A24) was authenticated and then deposited in the herbarium of Faculty of Pharmacy and Pharmaceutical Sciences, Isfahan, Iran. Samples of wild P. spinosa were collected in the middle of the flowering period. The samples were harvested every three-hour over a 12-hour period from 7:00 AM to 7:00 PM.
3.2. GC/MS Analysis
The hydrodistilled aerial parts oils of P. spinosa were analyzed by GC and GC/MS. Gas chromatography analysis was carried out using Perkin-Elmer 8500 gas chromatograph with flame ionization detector (FID) detector and a BP-1 capillary column (39 m × 0.25 mm; film thickness 0.25 µm). The carrier gas was helium with a flow rate of 2 mL/min, the oven temperature for the first 4 minutes kept at 60˚C and then increased at 4˚C/min until reached to the temperature of 280˚C, injector and detector temperatures were set at 280˚C. Confirmation of peak identity was effected by co-chromatography with standards and GC-MS. The mass spectra were recorded on a Hewlett Packard 6890 MS detector coupled with Hewlett Packard 6890 gas chromatograph equipped with HP-5MS capillary column (30 m × 0.25 mm; film thickness 0.25 µm). The gas chromatography condition was as mentioned previously. Mass spectrometer condition was as follow: ionized potential 70 eV, source temperature at 200˚C. Identification was based on retention data and computer matching with the Wiley 275.L library as well as by comparison of electron-impact-mass spectra (EI-MS) with those relevant reference samples and the literature (25, 26).
4. Results
The hydrodistilled aerial parts oil of Pycnocycla spinosa , collected on different time of day, was analyzed and thirty-four components identified, of which several constituents were found with diurnal variation. The GC chromatogram of P. spinosa essential oil is presented in Figure 1 and diurnal variations of fluctuating monoterpenoid and sesquiterpenoid components are shown in Table 1.
GC Chromatogram of P. spinosa Essential Oil
The Diurnal Variation of Fluctuating Constituents in the Essential oil of P. Spinosa a
| Compounds | 7:00 AM | 10:00 AM | 1:00 PM | 4:00 PM | 7:00 PM |
|---|---|---|---|---|---|
| P-cymene | 2.94 | 0.16 | 1.40 | 1.56 | 4.19 |
| t-β-ocimene | 1.21 | 1.49 | 2.19 | 0.11 | 0.00 |
| β-citronellol | 7.26 | 5.01 | 5.67 | 8.11 | 1.55 |
| Citronellyl Pentanoate | 10.32 | 14.31 | 7.31 | 18.17 | 10.53 |
| Geranyl isovalerate | 17.91 | 19.56 | 7.75 | 11.61 | 23.99 |
| α-humulene | 1.32 | 1.11 | 0.00 | 0.46 | 0.57 |
| Caryophyllen oxide | 3.99 | 0.00 | 0.00 | 0.0 | 4.60 |
| α-cadinol | 2.86 | 0.59 | 0.00 | 2.12 | 3.01 |
| α-eudesmol | 5.72 | 6.46 | 3.46 | 4.11 | 5.12 |
As presented in Table 1, the fluctuating monoterpenoid constituents were p-cymene, trans-β-ocimene, β-citronellol, citronellyl pentanoate, and geranyl isovalerate. Also four fluctuating sesquiterpenoid constituents were α-humulene, caryophyllen oxide, α-cadinol, and α-eudesmol (see Table 1). Several studies on aromatic plants have shown that the essential oil composition may vary considerably throughout a year (27, 28). The results showed that the content of p-cymene in the essential oil in different daily times 0.16 - 4.19% varied, and of geranyl isovalerate did 7.75 - 23.99% (see Table 1). Seasonal variation has also been noticed for p-cymene in the essential oil of Origanum onites (29). Results of diurnal variation of β-citronellol and citronellyl pentanoate were correlated. β-citronellol and citronellyl pentanoate reached to their lowest level at 7:00 and 1:00 PM. respectively, while both components reached to their highest levels at 4:00 PM. Similarly, it was reported that the percentage of citronellol, main components of rose oil, increased with delay in harvesting. Geraniol content of rose oil was maximum when the flowers were harvested at 10:00 AM, but after that there was significant reduction in its concentration up to 06:00 PM (24). As illustrated in Table 1, there is severing drop in citronellyl pentanoate content at 1:00 PM during day period. It may indicate some correlation between β-citronellol content and the level of its pentanoate ester. Results of diurnal variation of sesquiterpenes, α-humulene, caryophyllen oxide, α-cadinol, and α-eudesmol are presented in Table 1. Seasonal and diurnal variation has also been noticed for Hymenaea courbaril, Copaifera officinalis, and Copaifera pubiflora, which content of sesquiterpenes varies greatly during the year (30). α-cadinol showed the highest concentration at 7:00 PM. Also plant harvested early in the morning at 7:00 a.m. and late evening at 7:00 PM. provided essential oil with a high caryophyllen oxide content. Seasonal variation also was observed for this compounds (5). These variations were probably are related to the temperature or light variations. Plant cells are dependent on light for their growth and development. Light is also important for the production of metabolites by plant cells, and so also are irradiance, wavelength, and exposure time. As illustrated in Table 1, α-humulene reached to its highest level at 7:00 AM, while the lowest level was observed at 1:00 PM. In contrast, this compound was reported to be at highest level at 2:0 PM in Rosa damascene essential oil (31). It seems its fluctuation may not be related to the temperature or light but probably to genus and genetics of the plant. Caryophyllen oxide and α-cadinol reached their highest level at 7:00 PM. The highest content of eudesmol was observed when the plant was harvested at 10:00 AM. Variation in the other mono- and sesquiterpenes due to time were not significant.
5. Discussion
The interesting point to note is that diurnal cycles characterize the accumulation of 5 monoterpenes and 4 sesquiterpenes of thirty-four components identified in the essential oils of P. spinosa. Such variation has been reported in many compounds of the plants (32, 33). It seems that this is an expression of changes in enzymatic activities; such variations are suggested to be probably caused by variations in temperature or light conditions in different courses of the day (34). Light effects on the accumulation of secondary metabolites may occur on three different levels; through direct control of product concentrations, influences on membrane permeability, and influence on enzymatic reactions. The latter may occur either by varying enzyme activities or altering the concentrations of the involved enzymes. In conclusion, variations in essential oil components of P. spinosa in response to diurnal changes may indicate that essential oil with different qualities can be obtained according to the harvest season and harvest time of the plant.
Acknowledgements
References
-
1.
Mozaffarian V. A dictionary of Iranian plant name. Tehran: Farhang Moaser; 1996.
-
2.
Sadraei H, Asghari G, Naddafi A. Relaxant effect of essential oil and hydro-alcoholic extract of Pycnocycla spinosa Decne. exBoiss. on ileum contractions. Phytother Res. 2003;17(6):645-9. [PubMed ID: 12820233]. https://doi.org/10.1002/ptr.1217.
-
3.
Sadraei H, Asghari G, Behzad S. Bioactivity-guided isolation of spasmolytic components of Pycnocycla spinosa Decne ex Boiss. Res Pharm Sci. 2011;6(2):81-6. [PubMed ID: 22224090].
-
4.
Sadraei H, Asghari G, Shams M. Antidiarrheal action of hydroalcoholic extract of Pycnocycla spinosa in comparison with loperamide and dicyclomine. Iranian J Pharm Res. 2011;10(4):835-41.
-
5.
Mahmoudi Z. Composition of the essential oil of Pycnocycla Spinosa Decne. ex. Boiss. from Isfahan. DARU J Pharm Sci. 2001;9(3-4):28-9.
-
6.
Asghari G, Houshfar G, Mahmoudi Z. Seasonal Variation of Mono-and Sesquiterpenes in the Essential Oil of Pycnocycla Spinosa Decne. ex Boiss. Iranian J Pharm Res. 2010;1:61-3.
-
7.
Dickson RE. Diurnal changes in leaf chemical constituents and (14)C partitioning in cottonwood. Tree Physiol. 1987;3(2):157-71. [PubMed ID: 14975828].
-
8.
Badri DV, Loyola-Vargas VM, Broeckling CD, Vivanco JM. Root secretion of phytochemicals in Arabidopsis is predominantly not influenced by diurnal rhythms. Mol Plant. 2010;3(3):491-8. [PubMed ID: 20154222]. https://doi.org/10.1093/mp/ssq004.
-
9.
Rosa EAS, Heaney RK, Rego FC, Fenwick GR. The variation of glucosinolate concentration during a single day in young plants of Brassica oleracea var acephala and capitata. J Sci Food Agric. 1994;66(4):457-63. https://doi.org/10.1002/jsfa.2740660406.
-
10.
Itenov K, Molgaard P, Nyman U. Diurnal fluctuations of the alkaloid concentration in latex of poppy Papaver somniferum is due to day–night fluctuations of the latex water content. Phytochem. 1999;52(7):1229-34. https://doi.org/10.1016/S0031-9422(99)00420-3.
-
11.
Brown PD, Tokuhisa JG, Reichelt M, Gershenzon J. Variation of glucosinolate accumulation among different organs and developmental stages of Arabidopsis thaliana. Phytochem. 2003;62(3):471-81. https://doi.org/10.1016/S0031-9422(02)00549-6.
-
12.
Zeeman SC, Smith SM, Smith AM. The diurnal metabolism of leaf starch. Biochem J. 2007;401(1):13-28. [PubMed ID: 17150041]. https://doi.org/10.1042/BJ20061393.
-
13.
Hemm MR, Rider SD, Ogas J, Murry DJ, Chapple C. Light induces phenylpropanoid metabolism in Arabidopsis roots. Plant J. 2004;38(5):765-78. [PubMed ID: 15144378]. https://doi.org/10.1111/j.1365-313X.2004.02089.x.
-
14.
Birecka H, Zebrowska J. Diurnal changes in the alkaloid content in Lupinus albus, Lupinus luteus. Bull Acad Polon Sci Ser Sci Biol. 1960;8:339-41.
-
15.
Hopfinger JA, Kumamoto J, Scora RW. Diurnal variation in the essential oils of Valencia orange leaves. Am J Botany. 1979:111-5. https://doi.org/10.2307/2442513.
-
16.
Ramezani S, Ramezani F, Rasouli F, Ghasemi M, Fotokian MH. Diurnal variation of the essential oil of four medicinal plants species in central region of Iran. Res J Biol Sci. 2009;4(1):103-6.
-
17.
Chang X, Alderson PG, Wright Ch J. Variation in the Essential Oils in Different Leaves of Basil (Ocimum basilicum L.) at Day Time. Open Horticulture J. 2009;2:13-6. https://doi.org/10.2174/1874840600902010013.
-
18.
de Vasconcelos Silva MG, Craveiro AA, Abreu Matos FJ, Machado MIL, Alencar JW. Chemical variation during daytime of constituents of the essential oil of Ocimum gratissimum leaves. Fitoterapia. 1999;70(1):32-4. https://doi.org/10.1016/S0367-326X(98)00020-3.
-
19.
Angelopoulou D, Demetzos C, Perdetzoglou D. Diurnal and seasonal variation of the essential oil labdanes and clerodanes from Cistus monspeliensis L. leaves. Biochem Sys Ecol. 2002;30(3):189-203. https://doi.org/10.1016/S0305-1978(01)00074-6.
-
20.
Yaldiz G, Sekeroglu N, Ozguven M, Kirpik M. Seasonal and diurnal variability of essential oil and its components in Origanum onites L. grown in the ecological conditions of Cukurova. Grasas Aceites. 2005;56(4):254-8. https://doi.org/10.3989/gya.2005.v56.i4.89.
-
21.
Gurbuz B, Ipek A, Basalma D, Sarihan EO, Sancak C, Ozcan S. Effects of diurnal variability on essential oil composition of sweet basil (Ocimum basilicum L.). Asian Jo Chem. 2006;18(1):285-8.
-
22.
Ayan AK, Cirak C, Yanar O. Variations in total phenolics during ontogenetic, morphogenetic, and diurnal cycles inHypericum species from Turkey. J Plant Biol. 2006;49(6):432-9. https://doi.org/10.1007/BF03031123.
-
23.
Esmaeilian Y, Galavi M, Ramroudi M, Mashhadi M, Boojar A. Diurnal variability of stigma compounds of saffron (Crocus sativus L.) at different harvest times. Ann Biol Res. 2012;3(3):1562-8.
-
24.
Cirak C, Saglam B, Ayan AK, Kevseroglu K. Morphogenetic and diurnal variation of hypericin in some Hypericum species from Turkey during the course of ontogenesis. Biochem Sys Ecol. 2006;34(1):1-13. https://doi.org/10.1016/j.bse.2005.06.004.
-
25.
Adams RP. Identification of Essential oils by Ion Trop Mass Spectroscopy. California: Academic Press; 2002.
-
26.
Baj T, Ludwiczuk A, Sieniawska E, Skalicka-Wozniak K, Widelski J, Zieba K, et al. GC-MS analysis of essential oils from Salvia officinalis L.: comparison of extraction methods of the volatile components. Acta Pol Pharm. 2013;70(1):35-40. [PubMed ID: 23610957].
-
27.
Zheljazkov VD, Astatkie T, Jeliazkova E. Year-round Variations in Essential Oil Content and Composition of Male and Female Juniper. Hort Sci. 2013;48(7):883-6.
-
28.
Kumar R, Sharma S, Sood S, Agnihotri VK, Singh B. Effect of diurnal variability and storage conditions on essential oil content and quality of damask rose (Rosa damascena Mill.) flowers in north western Himalayas. Sci Hortic. 2013;154:102-8. https://doi.org/10.1016/j.scienta.2013.02.002.
-
29.
Ozkan G, Baydar H, Erbas S. The influence of harvest time on essential oil composition, phenolic constituents and antioxidant properties of Turkish oregano (Origanum onites L.). J Sci Food Agric. 2010;90(2):205-9. [PubMed ID: 20355032]. https://doi.org/10.1002/jsfa.3788.
-
30.
ElSohly HN, Croom EM, Kopycki WJ, Joshi AS, McChesney JD. Diurnal and seasonal effects on the taxane content of the clippings of certain Taxus cultivars. Phytochem Anal. 1997;8(3):124-9.
-
31.
Leach GJ, Whiffin T. Ontogenetic, seasonal and diurnal variation in leaf volatile oils and leaf phenolics of Angophora costata. Aust Sys Botany. 1989;2(1):99-111. https://doi.org/10.1071/SB9890099.
-
32.
Staudt M, Bertin N, Hansen U, Seufert G, Cicciolij P, Foster P, et al. Seasonal and diurnal patterns of monoterpene emissions from Pinus pinea (L.) under field conditions. Atmos Environ. 1997;31:145-56. https://doi.org/10.1016/S1352-2310(97)00081-2.
-
33.
Guemuescue A, Ipek A, Sarihan EO, Guerbuez B, Kaya MD, Arslan N. Effects of diurnal and ontogenetic variability on essential oil composition of oregano (Origanum vulgare var. hirtum). Asian J Chem. 2008;20(2):1290-4.
-
34.
Bertin N, Staudt M, Hansen U, Seufert G, Ciccioli P, Foster P, et al. Diurnal and seasonal course of monoterpene emissions from Quercus ilex (L.) under natural conditions application of light and temperature algorithms. Atmos Environ. 1997;31:135-44. https://doi.org/10.1016/S1352-2310(97)00080-0.