Agriculture Reference
In-Depth Information
Synonyms —
Boswellia carterii
Birdw. var.
undulato-crenata
Engl.;
Boswellia bhar-dajiana
Birdw.;
Boswellia bhar-dajiana
var.
serrulata
Engl.;
Boswellia undulatocrenata
(Engl.) Engl.
Family —
Burseraceae
Common Names —
Arabian frankincense, bible frankincense, frankincense, incense, oliba-
num, olibanum tree
African Names —
Somali: mohor (tree), beyo (resin); Swahili: ubani
Description —
The tree may be 1.5 -8 m tall, branching from the base or with a distinct trunk;
bark is pale brown with some outer flaking, papery layers, and a thick reddish-brown inner resinif-
erous layer; young shoots are tomentos or rarely glabrous, and resin is copious and milky and dries
yellowish-brown.
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The leaves are clustered at tips of branches and are imparipinnate; leaflets are
opposite, in 6-8 pairs, oblong, with a crenate margin, and tomentose. Flowers are often in axillary
racemes, crowded at the end of branches; racemes are up to 10 cm. The calyx is 5-lobed. There are
5 petals, which are yellow-white and spreading. There are 10 stamens. The ovary is surrounded by
a fleshy disk. Fruits are capsules, obovoid, broadly pyriform, reddish-brown, glaborous, 8-12 mm,
3-5 angled, and opening by 3-5 valves.
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Habitat and Distribution —
The trees grow in stony soil. They adhere to boulders of rock
faces by means of a cushion- or disk-like swelling at the base of the trunk. This swollen base
seems to be important in stabilizing the tree and is best developed in trees growing on very steep
or exposed rocks but less so, or not at all, in the occasional trees that grow in gravel or in planted
specimens.
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They are found in Somalia and most parts of the Horn of Africa and up to Arabia.
Ethnomedicinal Uses —
Frankincense is used in traditional medicine for treatment of skin
diseases, wound healing, and general inflammation.
Boswellia
has been used for acne, amenorrhea,
cancer, analgesia, diuresis, antisepsis, cystitis, cervical spondylosis, and genital infections and as a
carminative, expectorant, and sedative. It is also used in religious ceremonies for spirit invocation
during serious negotiations and in burial rites. Frankincense resin is eaten as a general restorative
tonic and for skin care in the Horn of Africa and parts of the Sahel region. Edible frankincense
must be pure for internal consumption, meaning it should be translucent, with no black or brown
impurities. It is often light yellow with a (very) slight greenish tint. It is often chewed like gum, but
it is stickier because of its resinous composition.
Constituents —
The oleo-gum resin frankincense or olibanum is the most important com-
ponent of
Boswellia
species, and the chemical composition is of immense value in differentiating
members of the genus. Olibanum has been reported to be a rich source of monoterpenes, sequiter-
penes, and iridoids, as well as nonvolatile triterpenoic constituents such as ursane, oleanane, and
lupine, which are in many cases responsible for some of the observed biological activities. The pres-
ence of isoincensole acetate in both
B. sacra
and
B
.
carteri
has been used as the main diterpenic
chemotaxonomic biomarker. Although the diterpene also occurs in
Boswellia serrata
olibanum, the
presence of methylchavicol, methyleugenol, and an unidentified oxygenated sesquiterpene distin-
guishes
B. serrata
olibanum from the two other species. The characteristic chemical compounds of
Boswellia papyrifera
are the diterpenic biomarkers incensole and its oxide and acetate derivatives
n-octanol and n-octyl acetate.
Boswellia frereana
olibanum is devoid of diterpenes of the incensole
family but contains a high amount of many dimers of β-phellandrene. The chemical composition
of olibanum, which is demonstrated to be different for each
Boswellia
species, allowed the deter-
mination of the taxonomic origin of frankincense samples purchased on various markets in East
Africa, in the Near East, and in Yemen. Moreover, terpenic fingerprints allowed the botanical origin
of olibanum used in traditional incense mixtures to be identified.301
301
The volatile oil derived from
the olibanum consists of 75% monoterpenes, sesquiterpenes, monoterpenols, sesquiterpenols, and
ketones. It has a good balsamic and sweet fragrance, while the Indian frankincense oil has a very
fresh smell. The steam- or hydrodistilled frankincense oil does not contain any boswellic acid (BA)
as these components (triterpenoids) are nonvolatile and too large to come over in the steam distilla-
tion process, and such claims in proprietary products should be disregarded.
