Figure 1.
Silica-gel TLC analysis of the radiolabeled reaction products obtained from [14C]indole. The reaction products were partitioned at acidic pH into ethyl acetate and 50 ng of unlabeled IAA was added before concentration and application to the TLC plate. Except for the IAA standard and the boiled control, duplicate reactions were spotted in adjacent lanes, as shown. After development in solvent S1tlc, radiolabeled products were visualized using an AMBIS 4000 radioimaging system. The RF values of IAA and indole (as indicated on the abscissa) were confirmed by visualization of the indole and the added unlabeled IAA using the reagent of Ehmann (1977) and superimposing the two images. A potential intermediate that accumulated with the addition of unlabeled IAA (lanes D) and was not detected in the reactions with added unlabeled indole (lanes F) is indicated on the abscissa (I?). Quantification of radioactivity at the RF of IAA (obtained by software analysis of the scanned image and correction for counting efficiency) is shown in the bar graph at the top of the figure. The data on the graph for C, D, E, and F are the averages of the values from each pair of lanes shown.