Isolation, characterization and insect growth inhibitory activity of major turmeric constituents and their derivatives againstSchistocerca gregaria (Forsk) andDysdercus koenigii (Walk)

Abstract

Curcuminoids, the major colouring constituents of Curcuma longa (turmeric) rhizome powder, comprise mainly three closely related curcumins (I, II and III). A simple method has been devised for their ef®cient extraction and separation. Their structures have been con®rmed by 1 H NMR spectroscopy and unique mass fragmentation pattern. Curcumin-I, the major constituent has been converted to ®ve alkyl ether derivatives, which have been tested along with the parent compounds and other extractives for insect growth inhibitory activity against Schistocerca gregaria and Dysdercus koenigii nymphs. At 20 mg per nymph, benzene extract and dibutyl curcumin-I were the most active (60% inhibition) against S gregaria, whereas at 50 mg per nymph these substances exhibited moderate growth-inhibitory activity (45%) against D koenigii nymphs. At these concentrations, turmeric oil caused 50±60% nymphal mortality in both test insects. The insect control activity of most of the turmeric products was comparable to or better than that of a commercial neem formulation.

Curcumin and cyclopalladated complexes: A recipe for bifunctional biomaterials

“…2-Phenyl-4-quinoline-carboxylic acid was purchased from Aldrich and used as received while the curcumin, purchased from Aldrich, was used after separation into individual components by modification of a previous method [24] Commercial curcumin was separated by silica gel chromatography (hexane:CHCl 3 :MeOH) from the other minor components of the mixture, namely, demethoxycurcumin and bisdemethoxycurcumin. The first phase mixture from 9:1 to 1:10 (hexane: CHCl 3 ) yielded the separation of the pure curcumin by the other components, followed by a second phase mixture 9.5:0.5 (CHCl 3 :MeOH) that eluted the other curcuminoids.…”

Disruptive Effects of Two Curcuminoids (Demethoxycurcumin and Bisdemethoxycurcumin) on the Larval Development of Drosophila melanogaster

“…Curcuminoids, major components of C. longa rhizome powder, are known to show high insecticidal activity when used against various pests, such as Culex pipiens larvae [40]. Additionally, 45-60% growth inhibition and 10-15% mortality were confirmed as a result of an insect growth inhibition assay in Schistocerca gregaria (Forsskål, 1775) and Dysdercus koenigii (Fabricius, 1775), by injecting the nymphs with curcuminoids [41]. In our study, we investigated the impact of curcuminoids on D. melanogaster larvae.…”

The impact of curcumin on livestock and poultry animal's performance and management of insect pests

“…Agricultural insect pests controlled by botanicals from C. longa, including essential oils, chemical constituents, and other extracts, are known to be studied for their role as "crop protectors" (126). Hemanta Chowdhury et al (127) isolated and characterized turmeric components and derivatives, which were shown to have a modest insect growth inhibitory effect on Schistocerca gregaria (Forsk) and Dysdercus koenigii (Walk). These conclusions were made based on the inhibitory activities of the compounds in both insect species; however, they found that turmeric oil had a nymphal mortality rate of 60%, along with 10% abnormal growth compared to the test compounds.…”

“…Therefore, turmeric oil was insecticidal rather than growth-inhibiting. They concluded that curcumin-I, its dibutyl derivative (7), and the benzene extract of turmeric rhizome powder, which contains both turmerones and curcuminoids, were the most active (127).…”