Recovery of Aconitic Acid from Sweet Sorghum Plant Extract Using a Solvent Mixture, and Its Potential Use as a Nematicide

Abstract

Trans-aconitic acid (TAA) is naturally present in sweet sorghum juice and syrup, and it has been promoted as a potential biocontrol agent for nematodes. Therefore, we developed a process for the extraction of aconitic acid from sweet sorghum syrup. The process economics were evaluated, and the extract was tested for its capability to suppress the motility of the nematodes Caenorhabditis elegans and Meloidogyne incognita. Aconitic acid could be efficiently extracted from sweet sorghum syrup using acetone:butanol:ethanol mixtures, and it could be recovered from this solvent with a sodium carbonate solution, with an overall extraction and recovery efficiency of 86%. The estimated production cost was USD 16.64/kg of extract and this was highly dependent on the solvent cost, as the solvent was not recycled but was resold for recovery at a fraction of the cost. The extract was effective in reducing the motility of the parasitic M. incognita and causing over 78% mortality of the nematode when 2 mg/mL of TAA extract was added. However, this positive result could not conclusively be linked solely to TAA. An unidentified component (or components) in the acetone:butanol:ethanol sweet sorghum extract appears to be an effective nematode inhibitor, and it may merit further investigation. The impact of aconitic acid on C. elegans appeared to be entirely controlled by pH.

Harnessing the Power of Plants: A Green Factory for Bioactive Compounds

“…Other than having applications as nutraceuticals and therapeutics, plant-derived compounds can also be used as pesticides. In their study, Klasson and colleagues extracted aconitic acid from sweet sorghum syrup and used it as a nematicide [10]. The extract was found to effectively reduce the motility of the parasitic Meloidogyne incognita and cause a high mortality of the nematode.…”