icon Boswellia papyrifera (Del.) Hochst
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Family Burseraceae
Description
Frankincense or olibanum is the name given to hardened resinous exudate derived from different species of Boswellia. The principal frankincense producing species include B. papyrifera (Del.) Hochst, B. neglecta S. Moore and B. rivae Engl. occurring in Ethiopia, B. frereana Birdw. and B. carteri Birdw. (Syn. B. sacra) in Somalia, and B. serrata (salai guggal) in India. B. papyrifera is a tree that grows up to 12 m and is known to occur in Ethiopia, Eritrea, Sudan and in some parts of West Africa (Vollesen, 1989). This monograph deals mainly with one type of Frankincense obtained from Boswellia papyrifera. Resin from B. papyrifera tree is obtained by making incisions on the bark and allowing the white emulsion to exude out, which slowly dries into different shaped tears.
Image gallery
The tree in the Blue Nile Gorge (Ethiopia). Note that leaves, flowers and fruits appear at different times of the year.
Source: Photo by E. Dagne
The highly aromatic resin of B. papyrifera obtained from the bark of the tree
Source: Photo by E. Dagne
Common names
The resin of B. papyrifera is called Etan in Ethiopia. In commercial circles it is referred to as Tigray or Eritrean Type.
Parts used

Resin
Major uses
This resin is widely used as incense in Ethiopia, the surrounding countries including the Middle East and in many churches worldwide. The extract from the resin as well as the oil obtained by steam distillation find applications in traditional medicine, perfumes and fragrances, aromatherapy, pharmaceuticals, as flavor in the food and beverage industries, for making adhesives, chewing gum etc. 
Essential oils Boswellia papyrifera

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• Ethiopia

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HS code

3301.29.50.50
Production
Accurate information on area coverage and production is lacking. Wild B. papyrifera trees are estimated to be found on over 330,000 hectares of land in Tigray region and on over 600,000 hectares in Amhara region of Ethiopia. The average annual production is 2000 tons of incense, a figure believed to be very low as compared to the potential (Kindeya, 2003). Sudan also produces 2000 metric tons of same resin (Ibrahim and Osman, 2000).
Domestic consumption
In Ethiopia nearly 50% of the resin is consumed locally, thus exceeding 1000 tons per annum (Tilahun, 1997).
Export

Ethiopia and Sudan are the biggest exporters of B. papyrifera resin. Unofficial trade among producing countries makes it difficult to estimate volume of export. The annual volume of export from Ethiopia varies between 1000 and 2000 tons (Coppen, 1995; Kindeya, 2003).

According to information obtained from the Ethiopian Natural Gums Processing and Marketing Enterprise (NGPME), in the period 1996-2000 on the average 540 tons of frankincense and 70 tons of myrrh per year were exported from Ethiopia by the Enterprise. This resulted in an average annual earning of US$ 675,000 and $ 237,000 from frankincense and myrrh respectively. These figures do not represent the total export value from Ethiopia as private companies are also engaged in the business. In general, the supply of these products far exceeds the demand, indicating the high potential of these products for the economic development of Ethiopia.
Average price
The export price of the resin depends on the grade of frankincense and varies between $ 3-5 per kg.
Plant material
B. payrifera is a deciduous tree that grows up to 12 m. Its bark is white to brown and peels off in large flakes. Its leaves are compound with 11-29 leaflets. Its flowers are monocious and sweet scented, fruits are red capsules with 3 tapered seeds. It occurs in Ethiopia, Nigeria, Cameroon, Central African Republic, Chad, Sudan, Uganda and Eritrea. The wood is light and soft, it is used for fencing and to make household furniture. When the trunk of the tree is tapped, a white fluid oozes out, which gradually dries (2-3 weeks) to yield the high valued frankincense resin. The tree is tapped at regular intervals throughout the dry season (in Ethiopia September to June). A tree yields on the average 2-3 kg of resin per year. After 4-5 years of tapping the tree needs to rest for 3-5 years (Kindeya, 2003). There is hardly any cultivation of this plant. It is wild and certainly organic.
Areas of production

B. papyrifera occurs mainly in two regions of Ethiopia namely Amhara, and Tigray regions of Ethiopia (Kindeya, 2003).
Plant products
The resin is used directly as incense or for chewing. Essential oil is produced by steam or hydro distillation but the yield is rather low. In the case of B. papyrifera it does not exceed 1%. There is also some interest in the absolute, which is obtained by macerating the resin with ethanol at room temperature. The yield of the extract after removal of the ethanol is higher than 50% (Dagne et al., unpublished).
Trade points

Ethiopian Natural Gums Processing and Marketing Enterprise (E-mail: natgum@telecom.net.et) exports various grades of frankincense resin and Ariti Herbal (www.aritiherbal.com) produces value added products.

The principal exporters of the resin or processed products of B. papyrifera are listed below (alos see the website: http://www.ethiopianchamber.com/1-download/exporters.doc)
-> Abbebaye C. C. P.L.C.
 5304, Addis Ababa
Ethiopia
 Tel: 251 115513973; Fax: 251 115 513965
-> Aguguba Natural Gum Exporter P.L.C.
 8722, Addis Ababa
Ethiopia
 Tel: 251 116 65 08 49 / 251 911-206737; Fax: 251 116 65 33 97
-> Aritiherbal Products
 30270, Addis Ababa
Ethiopia
 Tel: 251 911 645303 ; Fax: 251 111239468
 E-mail: edagne@yahoo.com
 Website: www.aritiherbal.com
-> Genale MIGS Trading P.L.C.
 2259, Nazareth
Ethiopia
 Tel: 251 115 560352; Fax: 251 115 513965
-> Guna Trading Houses S.C.
 80316, Addis Ababa
Ethiopia
 Tel: 251 116 652288; Fax: 251 116 654633
-> Kesete Tesfay General Import & Export
 26648, Addis Ababa
Ethiopia
 Tel: 251 911 210114; Fax: 251 116 614921
-> Natural Gum Processing and Mark Enterprise
 62322, Addis Ababa
Ethiopia
 Tel: 251 115 527082 / 83; Fax: 251 115 51 81 10

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Cultivation
B. papyrifera is not a cultivated plant. Some attempts have been made to propagate the plant from seedlings obtained from seeds and cuttings but with limited success. This is because of lack of knowledge on how to propagate a plant that has so far been known only in the wild (Kindeya, 2003).
Conservation
Several factors have been cited by Kindeya (2003) for the decline in the population of B. papyrifera. There is increasing population pressure in the areas where B. papyrifera occurs resulting in conversion of Boswellia woodlands to agricultural lands. Unregulated grazing has also damaged natural regeneration since its seeds and seedling are preferred by livestock and wild life. Improper incense tapping practices such as over-tapping, use of inappropriate tapping methods by unskilled labourers etc also contribute to decline of the population of this plant, thus making it one of the threatened species of the region. More efforts to rehabilitate B. papyrifera has been recommended such as closure of degraded sites from livestock grazing. It has also been pointed out that the preliminary attempts in North Ethiopia to promote plantations where this plant could be cultivated should be intensified. More silviculture work is needed including seed collection, studying nursery life span, planting time and post planting care (Kindeya, 2003).
Extract production ABI
Steam distillation of the resin yields highly aromatic oil which enjoys high demand in aromatherapy circles. The absolute obtained by extraction with ethanol has also immense potential in formulation of natural remedies and flavour preparations.  
Phyto-pharmaceuticals

Limited distillation facilities are available in Ethiopia and Sudan to separate the essential oil from the resin.

Scientific Information Icontop IconCollapse
Ethno-botanical info
Incense is burnt as insect repellent and also chewed by local people to quench thirst during hot days. Frankincense was used as a stimulant and to treat wounds and leprosy in China (Tucker, 1986). Frankincense is used in Arab homes to perfume clothes and purify the atmosphere. It is used in traditional festivities such as weddings and religious celebrations. It probably was one of the ingredients used by the ancient Egyptians for embalming.
Pharmacological studies

There are only limited pharmacological studies on the essential oil or extracts of B. papyrifera. The essential oil of B. papyrifera exhibited good activity against fungal strains with MIC values of 6.20 g/ml (Camrada et al., 2007). Since this resin is a good source of incensole and its derivatives, more work needs to be done on the pharmacological properties including anticancer studies in particular of the extract.
Chemical constituents
Diterpene biomarkers of B. payrifera and B. carteri

Although the gum resin of B. papyrifera coming from Ethiopia, Sudan and East Africa is believed to be the main source of frankincense of antiquity (Tucker, 1986), there was until recently a great deal of confusion in the literature regarding the chemical analysis of its resin as well as of the essential oil derived from it by steam or hydro distillation.

This was mainly due to the fact that analyses were done on commercial samples without establishing the proper botanical identity of the true source of the resin. This led to confusion because resins of several Boswellia species are traded as frankincense or olibanum in the world market such as the resins originating from B. carteri (Somalia and Oman), B. frereana (Somalia), B. papyrifera (Ethiopia and Sudan) and B. rivae (Ethiopia) and B. serata (India). B. sacra is now accepted to be synonymous to B. carteri.

The works of Dekebo et al., 1999, 2002; Basar, 2001, 2005; and Hamm et al., 2005, have clarified the distinction between B. carteri and B. payrifera. Dekebo et al., 1999, working on olibanum obtained from an identified plant established that the essential oil of B. papyrifera resin is characterized by the presence of octyl acetate (56%), octanol (8%) and smaller amounts of monoterpenes namely alpha-pinene, limonenene and linalool and only traces of sesquiterpenes. These results have later been confirmed by Hamm et al., 2005, who also established the finger print profile of the essential oil of B. carteri using samples of certified origin of B. carteri from Somalia and Oman. Thus the main constituents of the oil of B. carteri are established to be the monoterpenes alpha-pinene and limonene and the sesquiterpenes beta-caryophyllene and caryophyllene oxide. Octyl acetate which is abundant in B. papyrifera is absent in B. carteri. These results are significant because previously some studies on essential oil of olibanum in which octyl acetate was the major component were erroneously reported as coming from B. carteri (Abdel Wahab et al., 1987), Vernin et al., 1990, and Basar et al., 2001. The two species are further distinguished by the presence of incensole and incensole actetate only in B. payrifera (Hamm et al., 2005), thus making these two compounds as additional biomarkers for B. papyrifera. On the other hand B. frereana, a unique species found only in Somalia differs from the above two significantly. It is interesting to note that B. frereana is rich in the monoterepens, alpha-thujene and alpha-pinene, poor in sesquiterepnes and totally devoid of the diterpenes of the incnesole type. 
Quality control
TLC chromatograms of the petrol extracts of B. papyrifera, B. carteri and B. frereana
GC of hydro distilled oil–pinene (2.6%); 2: α of B. papyrifera (www.ics.trieste.it/essentialoils) 1: limonene (6.5%); 3: n-octanol (8.0%); 4: linalool (3.2%); 5: n-octyl acetate (56%).

The essential oil of B. papyrifera is quite distinct as shown in the figure below and as discussed above. Analysis of the petrol extract of the resin also reveals the diterpenic biomarkers of this species. The TLC chromatograms shown below (Dagne et al., unpublished) of the petrol extracts of B. papyrifera (BP), B. carteri (BC) and B. frereana (BF) reveal how useful this technique is to distinguish these resins. The yellow spots in BP are due to incensole (lower Rf) and incensole acetate. In GC the peaks above 46 min are due to diterpenes.
Safety data
The resin is chewed by people in the locality where the plant occurs to strengthen teeth and gums and to refresh the mouth. This can be taken as good indication of its safety.

Contacts Icontop IconCollapse
Ecology and Management of Boswellia papyrifera: Tanqua Abergelle Wereda (District), Tigray Region, Ethiopia, between 13° 14' and 13° 42' N and 38° 38' and 39° 02' E. Four project sites are selected located near Jijike Village where grazing is prohibited in the two sites. The Project Leader is Dr Kindeya Gebrehiwot. The collection and sorting of B. papyrifera in Tigray and Amhara northern regions of Ethiopia.
-> Mekelle University
 Contact: Dr Kindeya Gebrehiwot
 P.O. Box - 231, Mekelle
Ethiopia
 Fax: +251-344-409304
 Website: kindeyagl@yahoo.com
-> Natural Gum Processing and Marketing Enterprise
 Contact: Manager Mr. Teklehaimanot Nigatu
 PO Box 62322 Addis Ababa
Ethiopia
 Tel: 2511 552 7082 / 83 ; Fax: 2511 551 8110
 E-mail: natgum@ethionet.et

References Icontop IconCollapse
  • Abdel-Wahab, S. M., Aboutabl, E. A., El-Zalabani, S. M., Fouad, H. A., De Pooter, H. L. and El-Fallaha, B., 1987, The Essential Oil of Olibanum. Planta Med., 382-384
  • Basar, S., 2005, Phytochemical Investigations on Boswellia species, PhD Dissertation, University of Hamburg, Germany
  • Basar, S., Koch, A. and Koenig, W. A., 2001, A Verticillane-type Diterpene from Boswellia carteri Essential Oil. Flavour Fragr. J., 16: 315-318
  • Camarda, L., Dayton, T., Di Stefano, V., Pitonzo, R. and Schillaci, D., 2007, Chemical Composition and Antimicrobial Activity of Some Oleogum Resin Essential Oils from Boswellia spp (Burseraceae). Annali di Chimica, 837-844
  • Coppen, J. J. W., 1995, Flavours and fragrances of plant origin, Non-Wood Forest Products, 1, FAO, Rome
  • Dekebo, A., 2002, Chemical Studies of the Resins of Some Boswellia and Commiphora Species, PhD Dissertation, Addis Ababa University, Ethiopia
  • Dekebo, A., Zewedu, M. and Dagne, E., 1999, Volatile oils of frankincense from Boswellia papyrifera. Bull. Chem. Soc. Ethiop., 13: 93-96
  • Ibrahim, A. M. and Osman, M. E., 2000, Gums and Resins Production in Sudan. In: Chikamai, B. N., Mbiru, S. S., and Casadei, E. (eds.), Proceedings of the Network of Natural Gums and Resins in Africa (NGARA), Nairobi, Kenya
  • Kindeya, G. H., 2003, Ecology and Management of Boswellia papyrifera (Del.) Hochst. Dry Forest in Tigray, Northern Ethiopia. PhD Thesis, Culvillier Verlag, Gottingen, Germany
  • Mesele, A. and Dagne, E., 2007, MSc Thesis, Chemistry Department, Addis Ababa University, Ethiopia
  • Tilahun, G. and Legesse, N., 1997, The Effect of Different Pre-sowing Treatments on the Germination of Boswellia papyrifera, a key dryland tree. Ethiopian J. Natural Resources, 1: 37-55
  • Tucker, A. O., 1986, Frankincense and Myrrh, Economic Botany, 40: 445-433
  • Vernin, G., Boniface, C., Metzger, J., Maire, Y., Rakotorijaona, A., Fraisse, D. and Parkanyi, C., 1990, GC-MS Data Bank Analysis of the Essential Oils from B. frereana and Boswellia carteri Bird. Dev. Food Sci., 24: 511-542