Table of Contents
Simon, J.E., J. Quinn, and R.G. Murray. 1990. Basil: A source of essential
oils. p. 484-489. In: J. Janick and J.E. Simon (eds.), Advances in new crops.
Timber Press, Portland, OR.
Basil: A Source of Essential Oils*
James E. Simon, James Quinn, and Renee G. Murray
- ANALYSIS OF ESSENTIAL OILS
- Table 1
- Table 2
- Table 3
- Fig. 1
- Fig. 2
- Fig. 3
The genus Ocimum, (Lamiaceae formerly Labiatae), collectively called
basil has long been recognized as a diverse and rich source of essential oils
(Table 1). Ocimum contains between 50 to 150 species of herbs and
shrubs from the tropical regions of Asia, Africa, and Central and South America
(Bailey 1924, Hortus III 1976, Darrah 1980). Plants have square stems,
fragrant opposite leaves, and whorled flowers on spiked inflorescences (Darrah
1980). Interspecific hybridization and polyploidy, common occurrences within
the genus, have created taxonomic confusion and challenges, yet very little has
been published on basil taxonomy which follows the International Code of
Botanical nomenclature (Tucker 1986). The morphological diversity within basil
species has been accentuated by centuries of cultivation with great variation
in pigmentation, leaf shape and size, and pubescence. Taxonomy is further
complicated by the existence of chemotypes or chemical races within the species
that do not differ significantly in morphology.
Sweet basil (Ocimum basilicum L.), a common garden herb, is cultivated
in the United States for culinary purposes as a fresh herb and as a dried spice
(Fig. 1). While there are many cultivars (Simon and Reiss-Bubenheim 1987),
little information is available on the essential oil compounds responsible for
the plant's flavor and fragrance.
The essential oils of basil extracted via steam distillation from the leaves
and flavoring tops are used to flavor foods, dental and oral products, in
fragrances, and in traditional rituals and medicines (Guenther 1949, Simon et
al. 1984). Extracted essential oils have also been shown to contain
biologically-active constituents that are insecticidal (Deshpande and Tipnis
1977, Chavan and Nikam 1982, Chogo and Crank 1981), nematicidal (Chatterjee et
al. 1982), fungistatic (Reuveni et al. 1984) or which have antimicrobial
properties (Ntezurubanza et al. 1984). These properties can frequently be
attributed to predominant essential oil constituents, such as methyl chavicol,
eugenol linalool, camphor, and methyl cinnamate. Two minor components of the
essential oil of sweet basil, juvocimene I and II, have been reported as potent
juvenile hormone analogs (Nishida et al. 1984).
There are several types of basil oil in international commerce, each derived
principally from different cultivars or chemotypes of sweet basil. The oils of
commerce are known as European French or Sweet Basil, Egyptian, Reunion or
Comoro; and to a lesser extent Bulgarian and Java basil oils (Heath 1981). The
European type of basil oil considered to be the highest quality, and producing
the finest odor, characteristically contains: linalool; methyl chavicol; and to
a lesser extent 1,8-cineole, alpha-pinene; ß-pinene; myrcene; ocimene;
terpinolene; camphor; terpinen-4-ol; alpha-terpineol; eugenol; and
sesquiterpenes (Guenther 1949; Simon et al. 1984). Egyptian basil oil of
commerce is similar to European basil oil except that the concentration of
d-linalool is significantly lower while the concentration of methyl chavicol is
significantly higher (Fleischer 1981). In contrast, Reunion or Comoro basil
oil contains little if any d-linalool and is a harsher, spicy oil due to the
very high concentration of methyl chavicol, and to a lesser extent,
1,8-cineole, borneol camphor and eugenol (Lawrence et al. 1972 Simon et al.
1984). Bulgarian and Java basil oils are rich in methyl-cinnamate and eugenol
respectively (Heath, 1981).
Since 1984, we have been characterizing the chemical diversity of Ocimum
spp. to identify chemotypes of potential commercial interest. Genetic and
breeding studies have been initiated to increase the total essential oil
content (concentration) of commercial basil chemotypes and to increase the
content of specific oil constituents in other chemotypes such as those high in
methyl chavicol and methyl cinnamate. A germplasm collection of basil
(Ocimum spp.) consisting of more than 100 accessions from the USDA Plant
Introduction Station which include O. basilicum, O. canum, O. gratissimum,
O. kilimandscharicum, O. citriodorium, O. micranthum, O. sanctum plus other
commercial and noncommercial seed sources were field grown in central Indiana
and were initially screened organolepticahy for aroma and flavor differences.
Each accession and cultivar was harvested during full bloom.
More than 60 accessions of Ocimum spp. were selected for analysis based
on notable differences in aroma. These plants were then harvested at full
bloom and the essential oil extracted immediately from the flowering tops by
hydrodistillation using modified Clevenger traps. Analysis of the essential
oils was accomplished by gas chromatography using a Varian FID-GC (3700), with
a fused silica column (OV101) and integrator (4270) as previously described
(Charles and Simon 1990). Compound verification was by GC/Mass spectroscopy
using a Finnegan GC (9610) and MS (4000) with a Data General Nova/4 data
The essential oil content ranged from 0.04 to 0.70% (v/fresh weight) within the
Ocimum germplasm collection. Chemotypes high in 1,8-cineole,
trans-ß-ocimene, camphor, linalool methyl chavicol geraniol, citral eugenol,
methyl cinnamate, methyl eugenol, ß-caryophyllene, and elemene, and
ß-bisabolene were identified (Table 2). Accessions varied in essential oil
content, and showed diversity in growth, form, flowering and pigmentation (Fig. 2).
The major essential oil constituents found in commercial cultivars of 'Sweet
Basil' included linalool and methyl chavicol, followed by eugenol and
1,8-cineole. In the red-leaved ornamental cultivars of sweet basil 'Dark
Opal', methyl chavicol was only a minor constituent. Cultivars of basil
yielding high percentages of linalool, eugenol, citral (neral and geranial) and
ocimene were also identified (Table 3).
Once plants with distinct morphological and/or chemical characteristics are
identified in open pollinated crops, rapid progress can be made by mass
selection. This is particularly true with plant species such as those of
Ocimum, in which little plant breeding and crop improvement has
occurred. Such an approach has been used to identify and develop new lines of
Ocimum gratissimum L., rich in eugenol (Sobti et al. 1982). In 1987, we
initiated a study to develop a high methyl cinnamate basil as this type was of
interest to the perfume industry. Four accessions of basil were selected from
the screening program on the basis of high methyl cinnamate (MC): Cinnamon
Basil (Park Seed), 35% MC; USDA No. 170579,29% MC; Mexican Spice Basil, 17% MC;
and a selection from Morocco, 16% MC. The non-selected population consisted of
10 plants randomly selected from each accession in the greenhouse and
transplanted into the field. The selected population consisted of 10 plants
from each accession selected organoleptically (by scent) for high methyl
cinnamate. Field-grown plants were sampled during full bloom for essential oil
and methyl cinnamate content and open pollinated seed collected. Organoleptic
selection was successful as confirmed by essential oil analysis. The 1987
selected population had 15% more methyl cinnamate than the non-selected
population although the total content or concentration of essential oils was
essentially the same. In 1988, seed derived populations (1,000 plants of each)
were sampled at post full-bloom. Fifty plants from the 1988 selected
population were further selected organoleptically for high and low methyl
cinnamate and chemical analysis reconfirmed the effectiveness of selection for
higher methyl cinnamate.
In northern Indiana, field production of basil was initiated on a
semi-commercial basis (4 ha) in 1987 and 1988 to identify potential
production-related problems, and obtain initial yield information production
costs, and essential oil samples for industrial evaluation. The crop appears
to be well adapted to Indiana and can be grown and processed like peppermint
and spearmint long established essential oil crops in Indiana (Fig. 3). A
major field production problem included the lack of effective (and registered)
pre- and post-emergent herbicides for seasonal weed control. The presence of
weeds, particularly broadleaf species, in the "hay" (the partially field-dried
essential oil plant at extraction time), can detrimentally alter the odor of
essential oil and reduce the quality of the extracted oil product. The lack of
commercially available seed of cultivars (or chemotypes) with specific and
acceptable chemical characteristics has been a production limitation. However,
selection of unique chemotypes that have market potential could provide a
competitive edge for domestic growers.
Another limitation in the commercialization of domestically produced basil
essential oils is market penetration and the difficulty in producing basil oils
that match chemically and organoleptically with the currently imported basil
oils. Our initial studies indicate that basil essential oils produced in
Indiana can be price competitive with the imported product. With the correct
chemotypes of basil growers could produce standard basil oils and reduce or
partially replace imported basil oils. Export opportunities with the same
products need also to be explored. The production of new types of basil oils
rich in specific chemical constituents that have application in new products
will require a close relationship with both essential oil brokers and
- Bailey, L.H. 1924. Manual of cultivated plants. MacMillan Co. New York.
- Charles, D.J. and J.E. Simon. 1990. Comparison of extraction methods for the
rapid determination of essential oil content and composition of basil
(Ocimum spp.) J. Amer. Soc. Hort. Sci. 115:458-462.
- Charles, D.J., J.E. Simon, and K.V. Wood. 1990. Essential oil constituents of
Ocimum micranthum Willd. J. Agric. Food Chem. 38:120-122.
- Chatterje, A., N.C. Sukul, S. Laskal, and S. Ghoshmajumdar. 1982. Nematicidal
principles from two species of Lamiaceae. J. Nematol. 14:118-120.
- Chavan, S.R and S.T Nikam. 1982. Mosquito larvicidal activity of Ocimum
basilicum Linn. Indian J. Med Res. 75:220-222.
- Chogo, J. B. and G. Crank. 1981. Chemical composition and biological activity
of the Tanzanian plant Ocimum suave. J. Nat. Prod 44(3):308-311.
- Darrah, H.H. 1980. The cultivated basils. Buckeye Printing Company,
- Deshpande, R.S., and H.P. Tipnis. 1977. Insecticidal activity of Ocimum
basilicum L. Pesticides 11:1 1-12.
- Fleischer, A. 1981. Essential oils from two varieties of Ocimum
basilicum L. grown in Israel. J. Sci. Food Agric. 32:1119-1122.
- Guenther, E. 1949. The essential oils. VIII. Robert E. Krieger Publ. Co.
Malabar, Florida. p. 399-433.
- Heath, H.B. 1981. Source book of flavors. AVI. Westport, CT. p. 222-223.
- Lawrence, B.M., J.W. Hogg, S.J. Terhune and N. Pichitakul. 1972. Essential oils
and their constituents. IX. The oils of Ocimum sanctum and Ocimum
basilicum from Thailand. Flavor Ind Jan. 47-49.
- Nishida, R., W.S. Bowers, and P.H. Evans. 1984. Synthesis of highly active
juvenile hormone analogs, juvocimene I and II, from the oil of sweet basil
Ocimum basilicum L. J. Chem. EcoL 10:1435-1450.
- Ntezurubanza, L, J.J.C. Scheffer, A. Looman, and A. Baerhiem Svendsen. 1984.
Composition of essential oil of Ocimum kilimandscharicum grown in
Rwanda. Planta Medica 385-388.
- Reuveni, R, A. Fleisher, and E. Putievsky 1984. Fungistatic activity of
essential oils from Ocimum basilicum chemotypes. Phytopath. Z.
- Simon, J.E. and D. Reiss-Bubenheim. 1987. Field performance of American basil
varieties. Herb, Spice and Medicinal Plant Dig. 6 (1):1-4. (Mass. Coop. Ext.
- Simon, J.E., L.E. Craker, and A. Chadwick 1984. Herbs: an indexed bibliography,
1971-1980. The scientific literature on selected herbs, and aromatic and
medicinal plants of the temperate zone. Archon Books, Hamden, CT.
- Sobti, S.N., P. Pushpangadan and C.K. Atal. 1982. Clocimum: A new hybrid strain
of Ocimum gratissimum as a potential source of clove type oil, rich in
eugenol. In: Atal, C.K. and B.M. Kapur (eds.). Cultivation and utilization of
aromatic plants. Reg. Res. Lab., Jammu-Tawi, India p. 473-480.
- Staff of L.H. Bailey Hortorium. 1976. Hortus III. MacMillan, New York.
*Journal Paper No. 12,017, Purdue Univ. Agr. Expt. Sta., West Lafayette, IN
47907. This research was supported in part by a grant from the Purdue
University Agricultural Experiment Station (Specialty Crops Grant No.
Table 1. Chemotaxonomic classification of selected Ocimum
|Ocimum spp. ||Predominate constituents ||Reference|
|basilicum ||linalool methyl chavicol ||Guenther 1949|
| ||linalool, methyl cinnamate ||Guenther 1949|
| ||methyl chavicol ||Guenther 1949|
| ||methyl chavicol linalool ||Guenther 1949|
|canum ||camphor, limonene ||Xaasan 1981|
| ||methyl cinnamate, linalool ||Guenther 1949|
|citriodorium ||citral ||Darrah 1974|
|gratissimum ||eugenol ||Sobti 1979|
| ||thymol ||Guenther 1949|
|kilimandscharicum ||camphor ||Baslas 1968|
| ||1,8-cineole ||Ntezurubanza 1984|
|micranthum ||1,8-cineole, ß-caryophyllene, elemenes, eugenol ||Charles et al. 1990|
|sanctum ||eugenol ||Philip 1985|
| ||eugenol, ß-caryophyllene ||Philip 1985|
| ||methyl eugenol ß-caryophyllene ||Lawrence 1972|
|suave ||eugenol ||Chogo 1981|
|trichodon ||eugenol ||Ntezurubanza 1986|
|viride ||thymol ||Ekundayo 1986|
Table 2. Chemotaxonomic classification of selected Ocimum spp.
based on the USDA germplasm collection.z
zData of Quinn and Simon, Purdue University (unpublished).
|Ocimum spp. |
PI Number or cultivar name
|Predominant constituents ||Country of origin|
|175793 ||linalool ||Turkey|
|368699 ||linalool 1,8-cineole ||Yugoslavia|
|358465 ||linalool geraniol ||Yugoslavia|
|174285 ||linalool methyl chavicol ||Turkey|
|190100 ||methyl chavicol linalool ||Iran|
|253157 ||methyl chavicol citral ||Iran|
|170579-spsy ||methyl cinnamate, and Z isomer ||Turkey|
|170579 ||methyl cinnamate, methyl chavicol, linalool ||Turkey|
|Purdue selection ||methyl eugenol ||Thailand|
|500945 ||camphor (1-S) ||Zambia|
|500942 ||camphor (1-S), 1,8-cineole ||Zambia|
|500947 ||1,8-cineole, ß-pinene ||Zambia|
|500953 ||1,8-cineole, camphor (1-S) ||Zambia|
|500950 ||1,8-cineole, methyl cinnamate ||Zambia|
|Manglak ||citral, geraniol and isomer ||Thailand|
|gratissimum (var. suave)|
|211715 ||eugenol, ocimene (cis-b) ||Taiwan|
|Ka-prow ||eugenol, ß-caryophyllene, ß-elemene ||Thailand|
|414205 ||ocimene (trans-b), (ß-bisabolene) ||USA|
ysps = single plant selection
Table 3. The major essential oil constituents in basils cultivated in
zData of Simon and Quinn, Purdue University, unpublished, 1985.
|Cultivar ||Major essential |
|% of total|
|'Anise' ||methyl chavicol ||47|
| ||linalool ||30|
|'Bush' ||linalool ||35|
| ||eugenol ||16|
| ||1,8-cineole ||8|
|Dark Opal' ||linalool ||62|
| ||eugenol ||5|
| ||1,8-cineole ||5|
|'Lemon' ||geranial ||29|
| ||neral ||21|
| ||geraniol ||7|
| ||linalool ||7|
|'Picollo' ||linalool ||61|
| ||eugenol ||16|
|'Spice' ||eugenol ||30|
| ||ocimene ||17|
| ||methyl chavicol ||6|
|'Sweet Basil' ||linalool ||7-59|
| ||methyl chavicol ||5-29|
| ||eugenol ||2-12|
|'Sweet Fine' ||linalool ||57|
| ||eugenol ||17|
Fig. 1. Common sweet basil (Ocimum basilicum L.) cultivated in
the U.S. s a fresh culinary herb and dried spice.
Fig. 2. Germplasm collection of Ocimum spp. at the Purdue
University Vegetable Research Farm Lafayette, Indiana.
Fig. 3. Commercial harvest of Comoro basil oil in northern Indiana.
Last update September 5, 1997 aw