Diterpenoids from the Medicinal Plants of Africa
Louis Pergaud Sandjoa, Victor Kueteb, in Medicinal Plant Research in Africa, 2013
3.1
As other terpenoids, they are widespread in the plant kingdom, and most of them biosynthetically derive from geranylgeranyl diphosphate, which forms
Diterpenoids are divided into more than 45 classes; they are also found in marine organisms, which provide interesting skeletons (Figure 3.1) such as elisapterane (39).
Figure 3.1 presents the structural diversity and some of the skeletons of this class of compounds.
Introduction
Diterpenoids are secondary metabolites containing 20 atoms of carbon derived from the condensation of four isoprenyl units.As other terpenoids, they are widespread in the plant kingdom, and most of them biosynthetically derive from geranylgeranyl diphosphate, which forms
- acyclic (phytanes),
- bicyclic (labdanes, halimanes, clerodanes),
- tricyclic (pimaranes, abietanes, cassanes, rosanes, vouacapanes, podocarpanes),
- tetracyclic (trachylobanes, kauranes, aphidicolanes, stemodanes, stemaranes, atisanes, gibberellanes), and
- macrocyclic diterpenes (taxanes, cembranes, daphnanes, tiglianes, ingenanes) according to the cyclization that occurs [1].
Diterpenoids are divided into more than 45 classes; they are also found in marine organisms, which provide interesting skeletons (Figure 3.1) such as elisapterane (39).
Figure 3.1 presents the structural diversity and some of the skeletons of this class of compounds.
Plants
produce secondary metabolites in response to some external factors from
their biotope. To fight against these, the host plant produces
diterpenes, which could represent a problem in the living ecosystem of
that species because of the allelopathic activity of some of these
terpenoids against surrounding flora [24].
In addition, diterpenoid quinones from the roots of Salvia officinalis were earlier reported to display DNA-damaging effect on colonic and hepatic human cells cultured in vitro, although cytotoxic activity was observed [25]. Nevertheless, these structures are synthesized in the ertheless, these structures are synthesized in the plant cells following a well-established mechanism.
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