High toxicity and specificity of the saponin 3-GlcA-28-AraRhaxyl-medicagenate, from Medicago truncatula seeds, for Sitophilus oryzae

Table 1 Lethal time 50 (LT ₅₀ ) for different fractions of Medicago truncatula seed flour on Sitophilus oryzae

Fractions	amount per g of food	LT₅₀+/− SEM (day)
M. truncatula seed flour	10 mg	> 20
	50 mg	11.03 +/− 0.319
	100 mg	7.61 +/− 0.28
	250 mg	5.33 +/− 0.2
After solvents extraction	20 mg	3.79 +/− 0.13
Purified saponin	20 μg	not toxic
(3-GlcA-28-AraRhaxyl-medicagenate)	100 μg	16.57 +/− 1.89
	200 μg	12.96 +/− 0.52
	400 μg	9.59 +/− 0.39
	800 μg	8.42 +/− 0.25
	1200 μg	6.23 +/− 0.24
	1600 μg	5.63 +/− 0.28

The indicated amount of each powder was added to one gram of wheat flour. The food produced was given to weevils and mortality recorded every day for 20 days.