As can be seen in Table 2, ethanol-ultrasound (EU) extract was the best extract, followed by methanol-ultrasound (MU), methanol-maceration (MM), and ethanol-maceration (EM). After these, ethanol/water (50:50)-ultrasound (E50U), methanol/water (50:50)-ultrasound (M50U), methanol/water (50:50)-maceration (M50M), and ethanol/ water (50:50)-maceration (E50M) extracts were at the next degree. Aqueous extracts were at the lowest degree. Ultrasound can have a positive effect on ethanol, ethanol/water (50:50), and water solvents, so that the extracts obtained from ultrasound-assisted extraction method with the above solvents can make a significant difference in terms of phenolic compounds with similar extracts obtained from the maceration method, while there were no significant differences among MU and MM and also between M50U and M50M. This is due to the effect of solvent properties such as vapor pressure, viscosities, and surface tension on incidence of cavitation. The value of these properties for ethanol, methanol, and water has been shown in Table 3. The effect of vapor pressure in ultrasonication is related to the production of cavitational bubbles. It means that solvents with lower vapor pressure produce fewer cavitational bubbles that require higher force to collapse. So, during extraction, plant tissues are disrupted with more intensity. On the other hand, the solvents with high vapor pressure produce more bubbles but with less force to collapse. So, these kinds of solvents are not very effective for extraction. In the case of viscosity, liquids with low viscosity are more effective, because ultrasonic intensity applied could more easily overcome molecular force of the liquids with low viscosity. In addition, a liquid with low viscosity can easily penetrate into plant texture, because of its low density and high diffusivity. Liquids’ surface tension is another feature that contributes to the formation of cavitational bubbles. In the liquids with lower surface tension, cavitational bubbles are created more easily, because ultrasonic intensity applied could more easily exceed the surface tension force (Mason et al. 1996). As can be seen in Table 3, ethanol and methanol have a similar surface tension, so we discuss about two other factors. Although viscosity of ethanol is higher than that of methanol, but because of its lower vapor pressure, bubbles require higher force to collapse, so more energy is released to disrupt plant tissue. Low viscosity of methanol leads to formation of higher cavitational bubbles but, due to their high vapor pressure, they decompose with less intensity (Hemwimol et al. 2006). In the presence of water, extraction of phenolic compounds decreased due to the high polarity of mixture, but in the presence of 50% water, extraction of phenolic compounds increased due to the relative increase in the polarity and also due to the increase in the swelling of plant tissue. In addition, the presence of water leads to a decrease in viscosity of mixture, therefore mass transfer was improved. When ultrasonification was applied, extraction of phenolic content increased in the presence of 50% water as with maceration method. In the presence of water, the intensity of ultrasonic cavitation increased due to the decrease in vapor pressure and viscosity of mixture (Rostagno et al. 2003). TPC in the aqueous extract was lower than its amount (65.02 mg/g) in the same extract of Peschel et al. (2007), but regarding methanolic extract of this study, TPC value was greater than its amount (1709 μg/g) in the same extract used by Suja et al. (2005). TPC values of evening primrose cake in hydro-alcoholic (659.51 mg/g) and aqueous extract (229.63 mg/g) (Peschel et al. 2007) and Adhatoda vasica in hydro-alcoholic (81.51 mg/g) and aqueous extract (92.04 mg/g) (Maurya and Singh 2010) were greater than those in sesame cake hydro-alcoholic and aqueous extract in this research.