Polyacetylenes in normal and waterstressed ‘Orlando Gold’ carrots (Daucus carota)

Abstract

The effect of water stress on the polyacetylenic constituents of carrots (Daucus carota L, cv 'Orlando Gold') was studied by liquid chromatographic analysis. Eleven polyacetylenes were isolated fiom plants grown in the greenhouse under normal conditions and under conditions simulating drought or waterlogging. Three compounds were ident$ed. These include the known carrot polyacetylenes falcarinol (cis-heptadeca-1,9-diene-4,6-diyn-3-01), falcarindiol (cis-heptadeca-l,9-diene-4,6-diyn-3,8-diol), and falcarindiol-3-monoacetate (cis-3-acetoxyheptadeca-l,9-diene-4,6-diyn-8-o1). Three of the eight unidentified compounds were produced only by one or both stressed samples. The other eight (including the three knowns) were less concentrated in the stressed samples than in the control.

Determination of polyacetylenes in carrot roots (Daucus carota L.) by high‐performance liquid chromatography coupled with diode array detection

“…Polyacetylenes are well-known antifungal compounds that may accumulate during post harvest storage or during growth in the field, and hence may explain large differences between carrot cultivars/genotypes in their total content of polyacetylenes as well as of individual polyacetylenes [13]. Other factors that have a significant impact on the polyacetylene content are water stress, storage time, location, root size and genotype [13,31,34]. The mean CV calculated as a mean for three replicates of each genotype clearly showed that there was a large variation in the content of polyacetylenes between the investigated genotypes (Table 4).…”

“…However, due to the low number of conjugated unsaturated bonds in their structures the excitation coefficients (e a6000 for two triple bonds in conjugation) of these compounds at their characteristic UV-maxima are generally very low and hence the sensitivity above 230 nm [25,31,33]. By detecting the compounds at 205 nm, the UV sensitivity is improved approximately ten times and consequently the detection and quantification limits of the polyacetylenes.…”

“…The polyacetylenes were detected at 205 nm. The structures of the polyacetylenes were elucidated by comparison of their spectral data (UV, MS, 1 H-NMR, 13 C-NMR and optical rotation) with that in the literature [11,21,29,31]. Representative samples (8 kg) of carrots were taken from each genotype and divided into three subsamples of 1.5 -2.0 kg carrots of first class quality representing each replicate.…”

Handbook of Plant Food Phytochemicals

“…In a greenhouse pot trial three novel polyacetylene compounds were found only in stressed carrots subjected to drought or waterlogged conditions. Levels of eight other polyacetylenes including falcarinol, falcarindiol and falcarindiol-3-acetate were lower in control samples, although an earlier field study by the same authors showed higher levels of polyacetylenes in field grown drought stressed carrots [95]. Both drought and salt stress cause production of ROS within the plant and result in increased levels of secondary metabolites, including phytochemicals.…”

Functional Metabolomics – a Useful Tool to Characterize Stress-Induced Metabolome Alterations Opening New Avenues Towards Tailoring Food Crop Quality

“…Moreover, abiotic factors, such as mechanical stress, is reported to increase the amounts of the key bitter tastants, members of the C17-polycetylenes, present in native carrots (Daucus carota L.) to efficiently high concentrations, causing a bitter off-flavor is perceived, occurring especially often during the production process for infant diet carrot products [79,80,[91][92][93][94][95][96][97][98]. In addition, a decrease in flavor quality accompanied by an increase in bitter taste has also been reported in raw hazelnuts (Corylus avellana L.) upon biotic stress challenges, such as upon infection by bugs, belonging to the hemipteran family, like Gonocerus acuteangulatus and Coreus marginatus [99].…”