Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/1996
Publication Date: N/A
Interpretive Summary: Sugary secretions by the silverleaf whitefly (Bemisia argentifolii), which are termed honeydew, cause millions of dollars of damage each year to cotton harvested in the United States. A program has been initiated to understand the chemical composition of these excretions so that cotton manufacturing processes can modified to eliminate the problems caused by honeydew. The sugars in these insect secretions have been found to be quite unusual. In this paper the discovery of a novel sugar and a compound similar to an amino acid (betaine) are reported. Current efforts are directed toward determining the contribution of these newly discovered materials to the sticky nature of honeydew and means of eliminating them from contaminated cotton fiber.
Technical Abstract: Oligosaccharides in the honeydew secreted by the silverleaf whitefly (Bemisia argentifolii) that were feeding upon cotton (Gossypium hirsutum L.) were isolated by gel permeation chromatography followed by gradient elution HPLC employing an amine column and an evaporative light- scattering detector. A novel tetrasaccharide was collected from the HPLC eluate and characterized by mass spectral and methylation analysis and by 1D and 2D NMR. The results of these analyses are consistent with a highly symmetrical, nonreducing tetrasaccharide: alpha-D- glucopyranosyl-(1,4)-alpha-D-glucopyranosyl-(1,1)-alpha-D- glucopyranosyl-(4,1)-alpha-D-glucopyranoside. In addition, a significant peak of glycine betaine (N,N,N-trimethylglycine) was detected in the HPLC chromatograms of sugars from this honeydew.