Isolation of a Novel Tetrasaccharide, Bemisiotetrose, and Glycine Betaine from Silverleaf Whitefly Honeydew

Oligosaccharides in the honeydew secreted by the silverleaf whitefly ( Bemisia argentifolii Bellows and Perring) 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 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 tetrasaccharide: O -α- d -glucopyranosyl-(1→4)- O -α- d -glucopyranosyl-(1↔1)- O -α- d -glucopyranosyl-(4←1)-α- 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.