# Phytochemical Analysis and Amoebicidal Evaluation of Different Agave Species
## 3 Results and Discussion  
Ethanolic Extracts of Agave tequilana, Agave angustifolia, Agave rhodacantha, and Agave maximiliana UV-Vis Analysis and Phytochemical Screening  
Several authors have proved that during phytochemical extraction, solvents have a significant impact on the level of polyphenols extracted [45]. In general, tannins, polyphenols, polyacetylenes, flavonoids, terpenoids, sterols, and alkaloids can be readily extracted with ethanol [46; 47; 48]. In this study, a UV-Vis spectroscopy analysis revealed six weak and strong, intense bands ranging in wavelength from 400 to 700 nm (Figure 1); as reported by other authors, these bands reveal the presence of alkaloids, flavonoids, terpenes, steroids, saponins, tannins, and coumarins [45; 48; 49; 50; 51; 52]. The profile showed the peaks at 409-414 nm, 499-506 nm, 535-539 nm, 558-561 nm, 607-614 nm, and 666 nm. The higher absorbance values were obtained from _A. tequilana_, followed by _A. angustifolia_ (Table 1). The fact that the Agave species had absorbance peaks of unequal intensity is not surprising to us since the phytochemical constituents of plants vary among species; also, the concentration depends on the metabolite type, the characteristics of the plant, the tissue, the stage of development, and climatic factors [53; 54; 55; 56; 57]. The phytochemical screening of the Agave extracts confirmed the presence of flavonoids, terpenes, steroids, saponins, tannins, and coumarins, the contents of which varied considerably among the Agave species. The concentration of terpenes was high (+++) in the four species analyzed, while tannins were moderately (++) present. Only _A. angustifolia_ and _A. rhodacanta_ presented high concentrations of flavonoids (+++). _A. maximiliana_ was found to be the species with the lowest concentrations of flavonoids, steroids, and coumarins (Table 2).  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multicolumn{2}{c}{**Ethanolic Extracts**} & \multicolumn{1}{c}{**Feak**} & **1** & **2** & **3** & **4** & **5** & **6** \\ \cline{2-7} \multirow{3}{*}{_A. angustifolia_} & Wavelength (nm) & 666 & 610 & 560 & 535 & 505 & 409 \\ \cline{2-7}  & Absorbance (arb. u) & **0.230** & 0.044 & 0.026 & 0.043 & 0.064 & **0.575** \\ \hline \multirow{3}{*}{_A. maximiliana_} & Peak & **1** & **2** & **3** & **4** & **5** & **6** \\ \cline{2-7}  & Wavelength (nm) & 666 & 611 & 558 & 537 & 503 & 412 \\ \cline{2-7}  & Absorbance (arb. u) & 0.090 & 0.024 & 0.018 & 0.020 & 0.044 & 0.185 \\ \hline \hline \end{tabular}
\end{table}
Table 1: UV–Vis absorbance peak intensity values of the ethanolic extracts of _A. angustifolia_, _A. maximiliana_, _A. rhodacantha_, and _A. tequilana_..  
\begin{table}
\begin{tabular}{|c|c|c|c|c|c|c|} \hline \multicolumn{2}{|c|}{**Ethanolic Extracts**} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} \\ \hline \multirow{3}{*}{_A. rhodacantha_} & **Peak** & **1** & **2** & **3** & **4** & **5** & **6** \\ \cline{2-7}  & Wavelength (nm) & 666 & 614 & 561 & 539 & 499 & 414 \\ \cline{2-7}  & Absorbance & 0.089 & 0.016 & 0.007 & 0.015 & 0.030 & 0.141 \\ \hline \multirow{3}{*}{_A. requilana_} & **Peak** & **1** & **2** & **3** & **4** & **5** & **6** \\ \cline{2-7}  & Wavelength (nm) & 666 & 607 & 561 & 537 & 506 & 409 \\ \cline{2-7}  & Absorbance & **0.378** & **0.112** & **0.079** & **0.105** & **0.119** & **0.930** \\ \hline \end{tabular}
\end{table}
Table 1: _Cont._  
Figure 1: UV–Vis absorbance spectra analysis of the ethanolic extracts of _A. angustifolia_, _A. maximiliana_, _A. rhodacantha_, and _A. tequilana_ from 300 to 800 nm.