INHIBITORS OF CHLOROPHYLL BIOSYNTHESIS FROM BULBS OF GLADIOLUS SPP

Compounds extracted with methanol from the bulbs of Gladiolus spp. wer e tested for inhibition of Chi accumulation in greening cress (Lepidiu m sativum L.) seedlings. For the biotest, cress seeds were imbibed wit h water for 8 h and then incubated in the dark with the test solution for 40 h. Chlorophyll accumulation was determined at the end of the su bsequent irradiation period of 8 h. Compounds active in this biotest w ere purified by several chromatographic steps and identified by thin-l ayer chromatography with staining reactions and by gas chromatography/ mass spectrometry. The following compounds were identified and their c oncentration for 50% inhibition of Chi accumulation determined: sucros e (75 mM) plus glucose (30 mM), 3-hydroxybenzoic acid methylester (0.4 9 mM) and 5-hydroxymethylfurfural (6.7 mM). The inhibitory action was compared with several substituted derivatives of the natural compounds .