In vitro elicitation, isolation, and characterization of conessine biomolecule from Holarrhena antidysenterica (L.) Wall. callus and its larvicidal activity against malaria vector, Anopheles stephensi Liston

摘要

AbstractIn vitro elicitation of an important compound conessine has been done in the bark-derived callus culture ofHolarrhena antidysenterica(L.) Wall. employing different elicitors. For induction of callus, green bark explants excised from field-grown plants were cultured on MS medium augmented with different concentrations (0, 1, 2.5, 5, and 10?μM) of various growth regulators such as BA, IBA, NAA, and 2,4-D either alone or in combinations. The maximum amount of conessine (458.18?±?0.89dμg/g dry wt.) was achieved in callus developed on MS medium supplemented with 5?μM BA and 5?μM 2,4-D through HPLC analysis. Elicitation in conessine content in the above callus was achieved employing a variety of organic (phenylalanine, tyrosine, chitosan, tryptophan, casein hydrolysate, proline, sucrose, and yeast extract) as well as inorganic elicitors (Pb(NO3)2, As2O3, CuSO4, NaCl, and CdCl2) in different concentrations. The optimum enhancement in conessine content (3518.58?±?0.28g?μg/g dry wt.) was seen at the highest concentration (200?mg/L) of phenylalanine. The enhancement was elicitor specific and dose dependent. The overall increment of the conessine content was seen in the order of phenylalanine > tryptophan > Pb(NO3)2 NaCl > As2O3 CdCl2 proline > yeast extract > CuSO41H-NMR, and HRMS which confirmed with the structure of conessine. The bioassays conducted with the isolated compound revealed a strong larvicidal activity againstAnopheles stephensiListon with LC50and LC90values being 1.93 and 5.67?ppm, respectively, without harming the nontarget organism,Mesocyclops thermocyclopoidesHarada, after 48?h of treatment. This is our first report for the isolation and elicitation of conessine in the callus culture ofH. antidysenterica.]]>