From the water extracts of heat-treated spinach chloroplast lamellae, five compounds were isolated by column chromatography and identified by paper chromatography, UV-, IR-, 1H-NMR- and 13C-NMR spectrometry: besides the major component, sucrose, 1 glyophilized material contained 197 mg oxalic acid, 4.6 mg uridine and uracil and 22 μg lumiflavin. Only the isolated lumiflavin stimulated photosynthetic oxygen reduction and H2O2 production by illuminated chloroplast lamellae. Evidence is presented that the stimulation of photosynthetic oxygen activation by water extracts of heat-treated chloroplast lamellae is most likely due to flavin derivative(s) (probably FAD) released from thylakoid-bound ferredoxin-NADP reductase by heat- and other treatments. Lumiflavin is artifactually derived from the solubilized flavin coenzymes during the isolation procedure
A Journal of Biosciences: Zeitschrift für Naturforschung C (ZNC) is an international scientific journal for the emerging field of natural and natural-like products. ZNC publishes original research on the isolation, bio-chemical synthesis and bioactivities of natural products, their biochemistry, pharmacology, biotechnology, and biological activity and innovative developed computational methods for predicting their structure and/or function.