ARS | Publication request: Differences in secondary metabolites in leaves from trees affected with the greening (HLB) disease

Submitted to: Florida State Horticultural Society Meeting
Publication Type: Abstract
Publication Acceptance Date: April 10, 2008
Publication Date: April 23, 2008
Citation: Manthey, J.A. 2008. Differences in secondary metabolites in leaves from trees affected with the greening (HLB) disease. Florida State Horticultural Society Meeting. Paper No. HP14.

Technical Abstract: Preliminary analyses by HPLC-MS of methanolic extracts of two sets of orange leaves that are symptomatic of the Greening Disease (HLB) have shown several consistent differences. The main flavonoids in symptomatic and nonsymptomatic leaves were monitored in the HPLC chromatograms at 330 nm, and significant differences were detected in certain hydroxycinnamates and flavone glycosides between the symptomatic and un-diseased leaves. Other differences were detected in the Total-Ion-Currents (TICs) of the mass spectral analyses of the leaf extracts. One main difference was the elevated concentration of a compound with a m/z of 187 amu, which was also visualized as an Ehlrich reagent positive band in normal phase TLC of symptomatic leaf extracts. Ehlrich reagent is useful for the detection of limonoids, as well as secondary amines, including alkaloids. Work is in progress to identify this compound.