or 7 by ESI-HR-MS in all cases, regardless of the solvent used, thus demonstrating that the RuAAC reaction can be used to derivatize naturally occurring alkynes present at low concentrations in complex extracts (Table ). After 4.5 hr of reaction, we detected between 1 and 3 chromatographically resolved regioisomers of 6, depending on the solvent and azide used, but only one chromatographically resolved isomer of 7, regardless of azide or solvent used. Ion counts for 7b and 7c were higher than for 7a, mirroring our result with control alkynes. We performed RuAAC derivatization of carrot extract both with and without 5 mM of reference alkyne 1 in the reaction mixture, and observed qualitatively similar levels of falacarindiol derivatives 6 and 7 in either case, showing that under these reaction conditions, alkyne competition for catalyst or azide does not dramatically affect the outcome of the reaction (Table ). The extracted ion chromatograms for the data underlying Table are shown in Supporting Informtaion Figure .