Biological activity on the extract of Derris elliptica: an optimization approach to investigate the effect of processing parameters on mortality of Artemia Salina

Abstract

Bio-pesticide has an increasing importance in both commercial agriculture and small plot subsistence farming. One of the sources of bio-pesticide is "Tuba' plant, also known as Derris elliptica. Rotenone (C23H33O6) is one of the bio-active compounds from the extract of Derris elliptica known to be harmless to plants, but highly toxic to many insects and relatively innocuous to mammals. From the preliminary results (of previous study), the optimization process was employed using central composite design (CCD) to study the effects of two processing parameters on mortality (LC50) of Artemia salina. The processing parameters studied were the types of solvent (acetone and ethanol), solvent-to-solid ratio (10 ml/g and 2 ml/g) and raw material particle size (0.5 mm and 5 mm). The biological activity (LC50) was evaluated for all treatment conditions generated from the Design Expert ®software. Various concentrations of rotenoids resin were prepared and exposed to brine shrimps for 6, 12 and 24 hrs. Next, the mortality of Artemia salina was evaluated using probit analysis. The results showed that rotenoids resin extracted from local plant species of Derris was very active (level of toxicity) whereby all treatments produced LC50less than 1 ppm irrespective of different processing parameters used. For that reason, rotenone and other toxic constituents available in the resin were considered the most important toxic constituents of Derris root and proved to exhibit strong "knock off' effect to the aquatic organisms.