Agriculture Reference
In-Depth Information
HO
H
3
C
CH
3
CH
3
H
3
C
O
H
3
C
CH
3
CH
3
γ
-tocopherol
Fig. 3.11.
Structure of
γ
-tocopherol, one of the constituents of vitamin E.
Inflorescence and leaf-derived products
protocol used for the leaves and flowers
(Fellermeier and Zenk, 1998; Mechoulam
and Hanus, 2000; de Meijer
et al
., 2003).
The two chemical compounds with psycho-
tropic and/or pharmacological properties
are THC and CBD (Mechoulam and Hanus,
2002). The quantitative ratio of these com-
pounds within the inflorescences allows
plants to be grouped into three distinct
classes (chemotypes). This classification is
used to determine those cultivars destined
for fibre production from those destined for
drug production (de Meijer
et al
., 2003).
THCs and CBDs are used and/or tested
in their pure form or together when evalu-
ating their clinical usefulness in the
treatment of various pathologies. A number
of pharmaceutical grade products are
available (Berman
et al
., 2004; Stott and
Guy, 2004; Wingerchuk, 2004; Makriyannis
et al
., 2005).
The principal class of products derived from
the inflorescences and leaves are the terpe-
nes, of which the cannabinoids are part.
These secondary metabolites are synthesized
by different types of glandular cells (stalked
and sessile) situated on the leaves or on dif-
ferent parts of the male and female flowers
(bract, anther, etc.).
A number of flavonoids and alkaloids have
also been described in the leaves of
C. sativa
.
That said, these products are of relatively little
significance, as they have no specific use
(Mechoulam and Hanus, 2000).
In terms of their economic value, only the
terpenes and cannabinoids (essential oils, fra-
grances and pharmacologically active products)
appear to be of interest.
THE CANNABINOIDS
.
The cannabinoids are a
family of molecules that characterize
C.
sativa
. Some cannabinoids possess pharma-
cological properties and can exert psycho-
tropic effects on humans and animals (Bello
et al
., 2003).
The cannabinoids are terpenophenolic
compounds with a typical 21-Carbon skeleton
composed of a phenolic ring (olivetol) with the
monoterpene geranyl (Fig. 3.12).
Among the 60 or so known cannabinoids
(Turner, 1980; Mechoulam and Hanus, 2000),
the most important family members are the
cannabidiols (CBD), the cannabigerols (CBG),
the tetrahydrocannabinols (THC), the canna-
binols (CBN), the cannabichromenes (CBC) and
the cannabicyclols (Mechoulam and Hanus,
2000) (Fig. 3.12).
It is thought that only the acid deriva-
tives are synthesized and stored in the plant
tissues. The neutral decarboxylated form
may be partially formed in the plant or dur-
ing the extraction process, depending on the
THE TERPENES
.
The terpenes are produced by
the same glandular structures that produce the
cannabinoids. They are polymers of isoprene
units (Fig. 3.13). The mono- (10 carbons or
2 units of isoprene) and sesquiterpenes (15
carbons or 3 units of isoprene) are often asso-
ciated with plant fragrances (Buchanan
et al
.,
2000). Some 60 or so monoterpenes and 40
or so sesquiterpenes have been isolated from
Cannabis flowers (Turner, 1980).
In the case of narcotic cannabis (flowers
and bracts), two monoterpenes (myrcene and
limonene) represent approximately 85% of all
the terpenes isolated (Fig. 3.13) (Ross and
ElSohly, 1996). Two sesquiterpenes, guaiol
and eudesmol, make up approximately 16%
(Hillig, 2004). Various other products are
found in concentrations below 2%. These
include pinene, linalool and caryophylene,
together with a multitude of trace terpenic
