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Nonnhoff J, Gröger H. Process Development of the Copper(II)-Catalyzed Dehydration of a Chiral Aldoxime and Rational Selection of the Co-Substrate. ChemistryOpen 2022; 11:e202100230. [PMID: 34889532 PMCID: PMC8734112 DOI: 10.1002/open.202100230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Revised: 10/24/2021] [Indexed: 11/16/2022] Open
Abstract
The access towards chiral nitriles remains crucial in the synthesis of several pharmaceuticals. One approach is based on metal-catalyzed dehydration of chiral aldoximes, which are generated from chiral pool-derived aldehydes as substrates, and the use of a cheap and readily available nitrile as co-substrate and water acceptor. Dehydration of N-acyl α-amino aldoximes such as N-Boc-l-prolinal oxime catalyzed by copper(II) acetate provides access to the corresponding N-acyl α-amino nitriles, which are substructures of the pharmaceuticals Vildagliptin and Saxagliptin. In this work, a detailed investigation of the formation of the amide as a by-product at higher substrate loadings is performed. The amide formation depends on the electronic properties of the nitrile co-substrate. We could identify an acceptor nitrile which completely suppressed amide formation at high substrate loadings of 0.5 m even when being used with only 2 equivalents. In detail, utilization of trichloroacetonitrile as such an acceptor nitrile enabled the synthesis of N-Boc-cyanopyrrolidine in a high yield of 92 % and with full retention of the absolute configuration.
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Affiliation(s)
- Jannis Nonnhoff
- Chair of Industrial Organic Chemistry and BiotechnologyFaculty of ChemistryBielefeld UniversityUniversitätsstrasse 2533615BielefeldGermany
| | - Harald Gröger
- Chair of Industrial Organic Chemistry and BiotechnologyFaculty of ChemistryBielefeld UniversityUniversitätsstrasse 2533615BielefeldGermany
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Perez VC, Dai R, Bai B, Tomiczek B, Askey BC, Zhang Y, Rubin GM, Ding Y, Grenning A, Block AK, Kim J. Aldoximes are precursors of auxins in Arabidopsis and maize. New Phytol 2021; 231:1449-1461. [PMID: 33959967 PMCID: PMC8282758 DOI: 10.1111/nph.17447] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 04/28/2021] [Indexed: 05/03/2023]
Abstract
Two natural auxins, phenylacetic acid (PAA) and indole-3-acetic acid (IAA), play crucial roles in plant growth and development. One route of IAA biosynthesis uses the glucosinolate intermediate indole-3-acetaldoxime (IAOx) as a precursor, which is thought to occur only in glucosinolate-producing plants in Brassicales. A recent study showed that overproducing phenylacetaldoxime (PAOx) in Arabidopsis increases PAA production. However, it remains unknown whether this increased PAA resulted from hydrolysis of PAOx-derived benzyl glucosinolate or, like IAOx-derived IAA, is directly converted from PAOx. If glucosinolate hydrolysis is not required, aldoxime-derived auxin biosynthesis may occur beyond Brassicales. To better understand aldoxime-derived auxin biosynthesis, we conducted an isotope-labelled aldoxime feeding assay using an Arabidopsis glucosinolate-deficient mutant sur1 and maize, and transcriptomics analysis. Our study demonstrated that the conversion of PAOx to PAA does not require glucosinolates in Arabidopsis. Furthermore, maize produces PAA and IAA from PAOx and IAOx, respectively, indicating that aldoxime-derived auxin biosynthesis also occurs in maize. Considering that aldoxime production occurs widely in the plant kingdom, aldoxime-derived auxin biosynthesis is likely to be more widespread than originally believed. A genome-wide transcriptomics study using PAOx-overproduction plants identified complex metabolic networks among IAA, PAA, phenylpropanoid and tryptophan metabolism.
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Affiliation(s)
- Veronica C. Perez
- Horticultural Sciences Department, University of Florida, Gainesville, FL, 32611
| | - Ru Dai
- Horticultural Sciences Department, University of Florida, Gainesville, FL, 32611
| | - Bing Bai
- Horticultural Sciences Department, University of Florida, Gainesville, FL, 32611
| | - Breanna Tomiczek
- Department of Chemistry, University of Florida, Gainesville, FL, 32611
| | - Bryce C. Askey
- Horticultural Sciences Department, University of Florida, Gainesville, FL, 32611
| | - Yi Zhang
- Department of Medicinal Chemistry, University of Florida, Gainesville, FL, 32610
| | - Garret M. Rubin
- Department of Medicinal Chemistry, University of Florida, Gainesville, FL, 32610
| | - Yousong Ding
- Department of Medicinal Chemistry, University of Florida, Gainesville, FL, 32610
| | | | - Anna K. Block
- Center for Medical, Agricultural and Veterinary Entomology, U.S. Department of Agriculture-Agricultural Research Service, Gainesville, FL, 32608
| | - Jeongim Kim
- Horticultural Sciences Department, University of Florida, Gainesville, FL, 32611
- Plant Molecular and Cellular Biology Graduate Program, University of Florida, Gainesville, FL, USA
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Zhang D, Song YH, Dai R, Lee TG, Kim J. Aldoxime Metabolism Is Linked to Phenylpropanoid Production in Camelina sativa. Front Plant Sci 2020; 11:17. [PMID: 32117366 PMCID: PMC7025560 DOI: 10.3389/fpls.2020.00017] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 01/09/2020] [Indexed: 05/03/2023]
Abstract
Plants produce diverse secondary metabolites. Although each metabolite is made through its respective biosynthetic pathway, plants coordinate multiple biosynthetic pathways simultaneously. One example is an interaction between glucosinolate and phenylpropanoid pathways in Arabidopsis thaliana. Glucosinolates are defense compounds made primarily from methionine and tryptophan, while phenylpropanoids are made from phenylalanine. Recent studies have shown that the accumulation of glucosinolate intermediate such as indole-3-acetaldoxime (IAOx) or its derivatives represses phenylpropanoid production via the degradation of phenylalanine ammonia lyase (PAL) functioning at the entry point of the phenylpropanoid pathway. Given that IAOx is a precursor of other bioactive compounds other than glucosinolates and that the phenylpropanoid pathway is present in most plants, we hypothesized that this interaction is relevant to other species. Camelina sativa is an oil crop and produces camalexin from IAOx. We enhanced IAOx production in Camelina by overexpressing Arabidopsis CYP79B2 which encodes an IAOx-producing enzyme. The overexpression of AtCYP79B2 results in increased auxin content and its associated morphological phenotypes in Camelina but indole glucosinolates were not detected in Camelina wild type as well as the overexpression lines. However, phenylpropanoid contents were reduced in AtCYP79B2 overexpression lines suggesting a link between aldoxime metabolism and phenylpropanoid production. Interestingly, the expression of PALs was not affected in the overexpression lines although PAL activity was reduced. To test if PAL degradation is involved in the crosstalk, we identified F-box genes functioning in PAL degradation through a phylogenetic study. A total of 459 transcript models encoding kelch-motifs were identified from the Camelina sativa database. Among them, the expression of CsKFBs involved in PAL degradation is up-regulated in the transgenic lines. Our results suggest a link between aldoxime metabolism and phenylpropanoid production in Camelina and that the molecular mechanism behind the crosstalk is conserved in Arabidopsis and Camelina.
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Affiliation(s)
- Dingpeng Zhang
- Horticultural Sciences Department, University of Florida, Gainesville, FL, United States
| | - Yeong Hun Song
- Horticultural Sciences Department, University of Florida, Gainesville, FL, United States
| | - Ru Dai
- Horticultural Sciences Department, University of Florida, Gainesville, FL, United States
| | - Tong Geon Lee
- Horticultural Sciences Department, University of Florida, Gainesville, FL, United States
- Gulf Coast Research and Education Center, University of Florida, Wimauma, FL, United States
- Plant Molecular and Cellular Biology Graduate Program, University of Florida, Gainesville, FL, United States
| | - Jeongim Kim
- Horticultural Sciences Department, University of Florida, Gainesville, FL, United States
- Plant Molecular and Cellular Biology Graduate Program, University of Florida, Gainesville, FL, United States
- *Correspondence: Jeongim Kim,
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Pasolli M, Dafnopoulos K, Andreou NP, Gritzapis PS, Koffa M, Koumbis AE, Psomas G, Fylaktakidou KC. Pyridine and p-Nitrophenyl Oxime Esters with Possible Photochemotherapeutic Activity: Synthesis, DNA Photocleavage and DNA Binding Studies. Molecules 2016; 21:E864. [PMID: 27376258 DOI: 10.3390/molecules21070864] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 06/22/2016] [Accepted: 06/28/2016] [Indexed: 12/20/2022] Open
Abstract
Compared to standard treatments for various diseases, photochemotherapy and photo-dynamic therapy are less invasive approaches, in which DNA photocleavers represent promising tools for novel “on demand” chemotherapeutics. A series of p-nitrobenzoyl and p-pyridoyl ester conjugated aldoximes, amidoximes and ethanone oximes were subjected to UV irradiation at 312 nm with supercoiled circular plasmid DNA. The compounds which possessed appropriate properties were additionally subjected to UVA irradiation at 365 nm. The ability of most of the compounds to photocleave DNA was high at 312 nm, whereas higher concentrations were required at 365 nm as a result of their lower UV absorption. The affinity of selected compounds to calf-thymus (CT) DNA was studied by UV spectroscopy, viscosity experiments and competitive studies with ethidium bromide (EB) revealing that all compounds interacted with CT DNA. The fluorescence emission spectra of the pre-treated EB-DNA exhibited a moderate to significant quenching in the presence of the compounds indicating the binding of the compounds to CT DNA via intercalation as concluded also by DNA-viscosity experiments. For the oxime esters the DNA photocleavage and affinity studies aimed to clarify the role of the oxime nature (aldoxime, ketoxime, amidoxime) and the role of the pyridine and p-nitrophenyl moieties both as oxime substituents and ester conjugates.
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Irmisch S, Zeltner P, Handrick V, Gershenzon J, Köllner TG. The maize cytochrome P450 CYP79A61 produces phenylacet aldoxime and indole-3-acetaldoxime in heterologous systems and might contribute to plant defense and auxin formation. BMC Plant Biol 2015; 15:128. [PMID: 26017568 PMCID: PMC4446944 DOI: 10.1186/s12870-015-0526-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 05/18/2015] [Indexed: 05/19/2023]
Abstract
BACKGROUND Plants produce a group of aldoxime metabolites that are well known as volatiles and as intermediates in cyanogenic glycoside and glucosinolate biosynthesis in particular plant families. Recently it has been demonstrated that aldoximes can also accumulate as part of direct plant defense in poplar. Cytochrome P450 enzymes of the CYP79 family were shown to be responsible for the formation of aldoximes from their amino acid precursors. RESULTS Here we describe the identification and characterization of maize CYP79A61 which was heterologously expressed in yeast and Nicotiana benthamiana and shown to catalyze the formation of (E/Z)-phenylacetaldoxime and (E/Z)-indole-3-acetaldoxime from L-phenylalanine and L-tryptophan, respectively. Simulated herbivory on maize leaves resulted in an increased CYP79A61 transcript accumulation and in elevated levels of L-phenylalanine and (E/Z)-phenylacetaldoxime. Although L-tryptophan levels were also increased after the treatment, (E/Z)-indole-3-acetaldoxime could not be detected in the damaged leaves. However, simulated herbivory caused a significant increase in auxin concentration. CONCLUSIONS Our data suggest that CYP79A61 might contribute to the formation of (E/Z)-phenylacetaldoxime in maize. Since aldoximes have been described as toxic compounds for insect herbivores and pathogens, the increased accumulation of (E/Z)-phenylacetaldoxime after simulated herbivory indicates that this compound plays a role in plant defense. In addition, it is conceivable that (E/Z)-indole-3-acetaldoxime produced by recombinant CYP79A61 could be further converted into the plant hormone indole-3-acetic acid after herbivore feeding in maize.
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Affiliation(s)
- Sandra Irmisch
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Straße 8, 07745, Jena, Germany.
| | - Philipp Zeltner
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Straße 8, 07745, Jena, Germany.
| | - Vinzenz Handrick
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Straße 8, 07745, Jena, Germany.
| | - Jonathan Gershenzon
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Straße 8, 07745, Jena, Germany.
| | - Tobias G Köllner
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Straße 8, 07745, Jena, Germany.
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Gonçalves RSB, Dos Santos M, Bernadat G, Bonnet-Delpon D, Crousse B. A one-pot synthesis of 3-trifluoromethyl-2-isoxazolines from trifluoromethyl aldoxime. Beilstein J Org Chem 2013; 9:2387-94. [PMID: 24367404 PMCID: PMC3869255 DOI: 10.3762/bjoc.9.275] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 10/08/2013] [Indexed: 12/31/2022] Open
Abstract
Functionalized 3-trifluoromethyl-2-isoxazolines and 3-trifluoromethylisoxazoles were easily prepared from trifluoromethyl aldoxime 2 under mild conditions by using DIB as oxidant. Theoretical studies of the reactivity of trifluoroacetonitrile oxide 4 toward olefins and alkynes were carried out. The 3-trifluoromethyl-2-isoxazolines were ring-opened with NaBH4 and NiCl2 to yield the corresponding trifluoromethylated γ-amino alcohols.
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Affiliation(s)
- Raoni S B Gonçalves
- BioCIS CNRS, Faculté de Pharmacie, Labex-LERMIT, Univ Paris Sud, 5 rue J. B. Clément, 92290 Châtenay-Malabry, France
| | - Michael Dos Santos
- BioCIS CNRS, Faculté de Pharmacie, Labex-LERMIT, Univ Paris Sud, 5 rue J. B. Clément, 92290 Châtenay-Malabry, France
| | - Guillaume Bernadat
- BioCIS CNRS, Faculté de Pharmacie, Labex-LERMIT, Univ Paris Sud, 5 rue J. B. Clément, 92290 Châtenay-Malabry, France
| | - Danièle Bonnet-Delpon
- BioCIS CNRS, Faculté de Pharmacie, Labex-LERMIT, Univ Paris Sud, 5 rue J. B. Clément, 92290 Châtenay-Malabry, France
| | - Benoit Crousse
- BioCIS CNRS, Faculté de Pharmacie, Labex-LERMIT, Univ Paris Sud, 5 rue J. B. Clément, 92290 Châtenay-Malabry, France
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Irmisch S, Unsicker SB, Gershenzon J, Köllner TG. Identification and characterization of CYP79D6v4, a cytochrome P450 enzyme producing aldoximes in black poplar (Populus nigra). Plant Signal Behav 2013; 8:e27640. [PMID: 24390071 PMCID: PMC4091388 DOI: 10.4161/psb.27640] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 12/23/2013] [Indexed: 05/21/2023]
Abstract
After herbivore feeding, poplar trees produce complex volatile blends containing terpenes, green leaf volatiles, aromatics, and nitrogen-containing compounds such as aldoximes and nitriles. It has been shown recently that volatile aldoximes released from gypsy moth (Lymantria dispar) caterpillar-damaged black poplar (Populus nigra) trees attract parasitoids that are caterpillar enemies. In western balsam poplar (P. trichocarpa), volatile aldoximes are produced by 2 P450 monooxygenases, CYP79D6v3 and CYP79D7v2. A gene fragment with high similarity to CYP79D6/7 was recently shown to be upregulated in herbivore-damaged leaves of P. nigra. In the present study we report the cloning and characterization of this gene, designated as CYP79D6v4. Recombinant CYP79D6v4 was able to convert different amino acids into the corresponding aldoximes, which were also found in the volatile blend of P. nigra. Thus, CYP79D6v4 is most likely involved in herbivore-induced aldoxime formation in black poplar.
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