Isolation, characterization and insect growth inhibitory activity of major turmeric constituents and their derivatives against Schistocerca gregaria (Forsk) and Dysdercus koenigii (Walk)
✍ Scribed by Hemanta Chowdhury; Suresh Walia; Vinod S Saxena
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 125 KB
- Volume
- 56
- Category
- Article
- ISSN
- 1526-498X
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✦ Synopsis
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.