CHARACTERIZATION OF DESERT DATE (Balanites aegyptiaca)

Although the precise mechanism of the interaction of saponins with the cell membrane is
not fully understood (Morrissey and Osbourn, 1999), it is generally accepted that the
antifungal activity of saponins is related to their ability to complex with sterols in the fungal
membranes and thereby cause a loss of membrane integrity (Keukens et al. 1995; Morrissey
and Osbourn 1999). It has also been suggested that the saponin-sterol membrane complexes
ultimately form aggregates that lead to the formation of membrane pores (Armah et al.,
1999).
B. aegyptiaca and saponins
A literature survey shows that B. aegyptiaca contains both spirostanol and furostanol
saponins (Liu and Nakanishi, 1982; Pettit et al., 1991; Hosney et al., 1992; Kamel, 1998)
together with flavonoid glycosides (Kamel et al. 1991), sapogenol, and 6-methyldisgenin
(Hosney et al., 1992). Liu and Nakanishi (1982) isolated three spirostanol saponins,
balanitin-1, -2, and -3 from 60% aqueous methanol extracts of the bark and root of
Balanites aegyptiaca. Pettit et al. (1991) isolated four new cytostatic steroidal saponins,
called balanitin-4, -5, -6, and -7, from the CH2Cl2/MeOH (1:1) extract of the kernels.
Hosney et al. (1992) reported balanitin-3 from fruit mesocarp using methanol extracts.
They also isolated a new furostanol saponin, balanitoside, and 6-methyldiosgen. Kamel et
al. (1991) have isolated two new steroidal saponins and two previously known saponins
from the water-extract of the mesocarp. The known saponins were previously isolated from
the rhizomes of Dioscorea gracillima (Kawasaki et al., 1974). These compounds can be
used as the starting materials in the synthesis of oral contraceptives, sex hormones, and
other steroids, such as corticoids and anabolic compounds for which there has been an
excellent market since the 1960s. Up to the present, diosgenin and related steroidal
saponins have been obtained commercially from the tubers of various Dioscorea species.
However, the need to discover alternative sources for these compounds has become crucial
because of decreasing supply and increasing demand for the plant resources currently in
use.
A significant number of works on isolation and structure determination of natural
products from the B. aegyptiaca have been carried out. However, almost all are from either
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