Environmental Engineering Reference
In-Depth Information
24
Diesel Trees
Blake Lee Joyce
University of Tennessee
Hani Al-Ahmad
University of Tennessee and
An-Najah National University
Feng Chen and C. Neal Stewart, Jr.
University of Tennessee
contents
24.1 Introduction ........................................................................................................................ 619
24.2 Chemicals Present in
Copaifera
Oleoresins ....................................................................... 620
24.3 Biosynthesis of
Copaifera
Oleoresins: What Conifers Can Teach Us ............................... 621
24.4 Biological Functions of Oleoresin ...................................................................................... 622
24.5 Oleoresin Production Ecology ............................................................................................ 623
24.6 Comparing Oleoresin to Diesel Fuel .................................................................................. 624
24.7 Future Scope of Research and Development ...................................................................... 626
References ...................................................................................................................................... 627
24.1 IntroductIon
The natural history of diesel trees has a long interaction with humans in the realm of economic
botany. Trees in the genus
Copaifera
belong to the subfamily Caesalpinioideae in the family
Fabaceae. In total, there are more than 70 species of
Copaifera
distributed throughout the world
with at least 30 species found in South and Central America, primarily in Brazil, four species in
Africa, and one in Malaysia and the Pacific Islands (Dwyer 1951, 1954; Hou 1994). The first species
in the genus
Copaifera
was described by George Marcgraf and Willem Pies in 1628, but no formal
species name was ascribed to the plant, although later it was deemed
Copaifera martii
on the basis
of the description by Veiga Junior and Pinto (2002). Oleoresin from a
Copaifera
tree was listed as
a drug in the London Pharmacopoeia in 1677 and to the United States Pharmacopoeia in 1820, and
Linnaeus first described the genus
Copaifera
in 1762 (Plowden 2004). Later, more descriptions
of
Copaifera
species were completed by Hayne in 1825 and Bentham in 1876 (Dwyer 1951). The
current taxonomy of the genus has been largely defined by Dwyer and Léonard, who resolved the
differences between the genera
Copaifera
and
Guibourtia
and further developed the New World
and African species descriptions in the early 1950s (Léonard 1949, 1950; Dwyer 1951, 1954).
Some species are still difficult to identify in the field, even to specialists, because of an incomplete
taxonomy and esoteric species differences that rely on intricate flower morphology and other
transient characteristics than can be difficult to ascertain or collect compared with leaf morphology.
To complicate this situation further,
Copaifera
trees have been known to only flower once every 2 or
619
