Microwave-assisted extraction of phenolic compounds from Canavalia ensiformis leaves: preparation and evaluation of prospective bioherbicide on control of soybean weeds

Darlan Ferreira Silva, Maria Olímpia Oliveira Rezende

Several chemical compounds are used for pest control in agriculture in order to increase productivity. It is scientific knowledge that such pesticides adversely affect human and animal health through contamination by these substances. Thus, the use of substances obtained from nature itself to combat pests and weeds is an alternative for the control of those and, consequently, prevent environmental contamination. This paper evaluated the aqueous extracts of jack-bean leaves (Canavalia ensiformis) as a prospective postemergent bioherbicide applied in the control of soybean weeds. The process of extraction of phenolic compounds was carried out in a digestion system by microwave, in vessels of 60 mL with approximately 2 g dry plant material and 30 mL of deionized water in pressurized system, followed by chromatographic injection. Optimal conditions for extraction were temperature of 100 °C, extraction time of 10 minutes and ramp of temperature of 5 minutes. Determinations were performed via HPLC-UV chromatography, based on peak ferulic acid compound in all assays. This study aimed to optimize a microwave-assisted extraction method and consequently evaluating these extracts as bioherbicide in soybean weeds.