Radiosynthesis of C-11 labeled auxin (3-indolyl[1-C]acetic acid) and its derivatives from gramine
نویسندگان
چکیده
3-Indolylacetic acid (IAA) is the major auxin in higher plants and plays a key role in plant growth and development. We report the rapid radiolabeling of the important plant hormone using carbon-11 (half life: 20.4 min) enabling in vivo imaging of its distribution and movement in whole plants. 3-Indolyl[1-C]acetic acid was synthesized in 2-steps: (1) reaction of gramine with [C]cyanide to give 3-indolyl[1-C]acetonitrile in 499% radiochemical purity; (2) hydrolysis of the intermediate in aqueous sodium hydroxide solution to give 3-indolyl[1-C]acetic acid in 498% radiochemical purity after HPLC purification. The overall nondecay corrected radiochemical yield was 28%, synthesis time was 68 min and specific activity was (0.7 mCi/nmol). Hydrolysis proceeded through the formation of 3-indolyl[1-C]acetamide and by varying the temperature of this step, either C-11 labeled acid or amide were obtained. This procedure provides unexpectedly high C-11 incorporation in a short time and using a simple and selective hydrolysis without the need of an indole-nitrogen protecting group or a typical leaving group. Since 3-indolylacetonitrile and 3-indolylacetamide are also intermediates in the biosynthesis of IAA, and also function as auxins, this versatile reaction makes all three of these labeled compounds available for imaging studies in whole plants in vivo.
منابع مشابه
Radiosynthesis of C-11 Labeled Auxin (3-Indolyl[1-11C]acetic Acid) and Its Derivatives from Gramine
متن کامل
Synthesis, absolute configuration and biological activities of both enantiomers of 2-(5,7-Dichloro-3-indolyl)propionic acid: a novel dichloroindole auxin and antiauxin.
Racemic 2-(5,7-dichloro-3-indolyl)propionic acid (5,7-Cl(2)-2-IPA) was synthesized from 5,7-dichloroindole-3-acetic acid by successive esterification, methoxycarbonylation, methylation, and double hydrolysis. The racemate was converted to diastereomeric esters of l-menthol; these were separated by recycling HPLC into two optically active diastereomers that were then hydrolyzed with p-TsOH to tw...
متن کاملBiosynthesis of vitamin B 12 : Identity of fragment extruded during ring contraction to the corrin macrocycle ( acetic acid / cobyrinic acid / isobacteriochlorins )
Incorporation experiments with labeled sirohydrochlorin and trimethylisobacteriochlorin demonstrate that ring contraction in vivo to the corrin macrocycle of vitamin B12 liberates acetic acid. The C-20 atom of the precursors becomes the acetate carboxyl carbon. The trimethylisobacteriochlorin isolated (1, 2) from the vitamin B12 producer Propionibacterium shermanii was proved (3, 4) to have str...
متن کاملGrowth-limiting Proteins in Relation to Auxin-induced Elongation in Lupin Hypocotyls.
The role of protein synthesis in auxin-induced cell elongation in lupin hypocotyl segments was studied using cycloheximide. Cycloheximide inhibited protein synthesis by 9 minutes. Experiments adding cycloheximide at various times before and after indolyl-3-acetic acid are reported. Estimates of the relative amounts of growth-limiting protein(s), and a first order rate constant for the apparent ...
متن کاملCYP83B1, a cytochrome P450 at the metabolic branch point in auxin and indole glucosinolate biosynthesis in Arabidopsis.
Auxins are growth regulators involved in virtually all aspects of plant development. However, little is known about how plants synthesize these essential compounds. We propose that the level of indole-3-acetic acid is regulated by the flux of indole-3-acetaldoxime through a cytochrome P450, CYP83B1, to the glucosinolate pathway. A T-DNA insertion in the CYP83B1 gene leads to plants with a pheno...
متن کامل