Research indicates the sweet potato as suitable raw materials to industrial production of
ethanol, with the ability to include small producers to agro-energy sector. At the same time,
some studies have shown the importance of this production is established on the principles of
biorefinery with use of secondary metabolites of this plant for pharmacological purposes. This
work was developed on the assumption that the phytosterols, secondary metabolites of great
importance herbal complement the phenolic compounds in the leaves of this plant. This work
aimed to determine phytosterols, phenolic compounds and evaluate the antioxidant activity in
the the leaves of four cultivars of Ipomoea batatas (L.) Lam. utilized in industrial ethanol
production. Adult leaves were collected four sweet potato cultivars, which were dried,
reduced to powder and subjected to ultrasonic extraction in of methanol / acetonitrile solution.
During concentration of the extract was the formation of two phases, which, by preliminary
prospecting was found that a was rich phytosterols (FRP) and the other in phenolic
compounds (FRPC). The FRP, it was determined the content of total phytosterols by
chlorogenic SPF method, which ranged from 132.35 ± 3.61 mg StgE / g to grow Duda to
195.21 ± 3.97 mg StgE / g to cultivate Amanda. In FRPC they were determined the contents
of total phenols by Folin-Ciocalteu method, flavonoid and total flavonols by the method of
complexation with aluminum chloride and the antioxidant activity by DPPH method. The
content of total phenols ranged from 140.84 ± 01.07 mg GAE / g to cultivate Duda and
151.20 ± 1.24 mg GAE / g to Marcela, flavonoid between 70.98 ± 0.61 mg ER / g to cultivate
Amanda and 121.58 ± 22.01 mg ER / g Marcela, Flavonols between 29.58 ± 0.65 mg ER / g
to cultivate Duda and 57.46 ± 0.87 to cultivate Marcela. The antioxidant activity was good in
most cultivars and showed a strong correlation with the phenolic content, more pronounced
with the flavonols. The best value of DPPH-EC50 was observed for Marcela (EC50 = 43.69 ±
0:22), which has antioxidant activity equal to the standard rutin in concentrations of 30, 60
and 120 μg / mL-1. The two fractions obtained were also subjected to analysis by highperformance
liquid chromatography (HPLC), which allowed the identification of stigmasterol
and β-sitosterol in the FRP and gallocatechin, catechin, rutin, ellagic acid, naringin, myricetin,
morin and quercetin in FRPC, the identified compounds are reported in the literature as
beneficial to human health. The data obtained in this study suggest the development of
research to assess the logistics of implementation of biorefinery in the production of ethanol
from I. batatas.
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