Isolation of Four New Indole-3-acetic Acid (IAA) Oxidative Metabolites, a Pair of Diasteromers 5-O-β-D-glucopyranosyl 3,5-Dihydroxy-2-indolinone-3-acetic Acid and 5-O-β-D-cellobiosyl 3,5-Dihydroxy-2-indolinone-3-acetic Acid from Rice Bran

Identification of Oxindoleacetic Acid Conjugates in Quinoa (Chenopodium quinoa Willd.) Seeds by High-Resolution UHPLC-MS/MS

“…Similarly, one hexose was found to be attached to the derivative that had a molar mass of 383 Da. The oxIAA derivatives have been previously found to be glycosylated; for example, in Zea mays seedlings, IAA is known to transform to oxIAA and then to OH-oxIAA and finally to OH-oxIAA-glucoside [ 24 ], also detected in rice bran [ 15 ]. The hexose moiety was detected by the neutral cleavage of 162 Da in many MeO-oxIAA derivatives ( Figure 3 A,D,F).…”

“…OxIAAs are considered to be catabolic derivates of IAA [ 12 , 13 , 14 , 15 , 24 ]. Based on our results, the catabolic products of IAA, at least in Chenopodium quinoa seeds, form a much more complex group of oxIAAs and their derivatives than, for instance, in Arabidopsis [ 13 ], Oryza sativa [ 14 , 15 ] and Zea mays [ 24 ].…”

“…For the final identification work, the seed material was ground into fine powder and 10 mg was extracted with mixed with 1.4 mL of acetone/water (4:1, v/v) and macerated overnight. Then, the samples were extracted twice with a similar volume of acetone/water OxIAAs are considered to be catabolic derivates of IAA [12][13][14][15]24]. Based on our results, the catabolic products of IAA, at least in Chenopodium quinoa seeds, form a much more complex group of oxIAAs and their derivatives than, for instance, in Arabidopsis [13], Oryza sativa [14,15] and Zea mays [24].…”

“…Then, the samples were extracted twice with a similar volume of acetone/water OxIAAs are considered to be catabolic derivates of IAA [12][13][14][15]24]. Based on our results, the catabolic products of IAA, at least in Chenopodium quinoa seeds, form a much more complex group of oxIAAs and their derivatives than, for instance, in Arabidopsis [13], Oryza sativa [14,15] and Zea mays [24]. The actual amounts of oxIAAs in quinoa seeds are so far unclear and, also whether they are affected by, e.g., cooking or not and, finally, whether these compounds possess any biological activity when ingested.…”

“…Just recently, Hayashi et al presented the major inactivation pathway for IAA which modulates auxin homeostasis in plant development in Arabidopsis [13]. Other oxidation products of IAA reported earlier are, for example, methyl-5-hydroxy-2-oxindole-3-acetic acid and its glycosides in rice (Oryza sativa) bran [14,15] and 7hydroxy-2-oxindole-3-acetic acid 7′-O-β-D-glucoside in maize (Zea mays) seedlings [5]. Quinoa metabolites have been analyzed with many different analytical techniques.…”