Environmental Engineering Reference
In-Depth Information
11.2.1.12
Stevia rebaudiana
(Bertoni)
S. rebaudiana
(Bertoni) Bertoni is a perennial shrub of the Asteraceae (Compositae) family native
to certain regions of South America (Paraguay and Brazil). It is often referred to as “the sweet
herb of Paraguay.” Stevioside, the main sweet component in the leaves of
S. rebaudiana
(Bertoni)
Bertoni tastes about 300 times sweeter than sucrose (0.4% solution).
Structures of the sweet components of
Stevia
occurring mainly in the leaves are given in
Figures 11.20 and 11.21. Their content varies between 4% and 20% of the dry weight of the
leaves depending on the cultivar and growing conditions. Stevioside is the main sweet compo-
nent. Other compounds present but in lower concentration are as follows: steviolbioside, rebau-
dioside A, B, C, D, E, F, and dulcoside A (Kennelly, 2002; Starrat et al., 2002). As the objects
of pharmacological research, stevioside and rebaudioside A have been thoroughly investigated.
In particular, they were shown to be absolutely safe (LD
50
> 10,000 mg/kg for stevioside and
8,000 mg/kg for rebaudioside), a hypotensive activity has been shown for stevioside and the lack
of such for rebaudioside (Koyama et al., 2003), metabolism in human gut organisms has been
investigated (Tolstikova et al., 2005).
Recently, an antiarrhythmic effect has been demonstrated for both glycosides (Starrat et al., 2002).
For example, preventive intravenous administration of these glycosides at the dose of 0.120 mg/kg
secures survival of up to 50% of the animals given a lethal dose of calcium chloride. In the adrena-
line arrhythmia model with similar administration regimen, only stevioside was shown to be effec-
tive. The survival rate was 50%. In the same arrhythmia models, both glycosides administrated at
the dose of 0.120 mg/kg after the administration of the arrythmogen failed to block arrhythmia that
had already developed (Tolstikova et al., 2009).
11.2.1.13 Complexes with Stevioside and Rebaudioside
Complexes of lappaconitine with stevioside were made with the molecular ratios ST:LA = 1:1,
4:1, 8:1, and 16:1. Their antiarrhythmic activity was studied using the earlier-stated arrhythmia
models.
As can be seen from Table 11.8, complexes with the composition 1:1 and 4:1 when adminis-
tered preventively ensure full protection from the development of calcium chloride and adrenaline
OH
OH
O
A
HO
O
OH
OH
OH
O
O
HO
O
C
O
HO
O
HO
OH
FIGURE 11.20
Structure of stevioside.
HOH
2
C
HOH
2
C
OHO
O
HO
O
HO
O
OH
HOH
2
C
O
H
3
C
O
CH
2
HO
HO
H
OH
C
H
H
3
C
HOH
2
C
O
O
HO
O
HO
OH
FIGURE 11.21
Structure of rebaudioside.
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