Carboxin

Last updated
Carboxin
Carboxin.svg
Names
Preferred IUPAC name
2-methyl-N-phenyl-5,6-dihydro-1,4-oxathiine-3-carboxamide
Identifiers
3D model (JSmol)
983249
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.023.665 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 226-031-1
PubChem CID
UNII
  • InChI=1S/C12H13NO2S/c1-9-11(16-8-7-15-9)12(14)13-10-5-3-2-4-6-10/h2-6H,7-8H2,1H3,(H,13,14) Yes check.svgY
    Key: GYSSRZJIHXQEHQ-UHFFFAOYSA-N Yes check.svgY
  • CC1=C(SCCO1)C(=O)NC2=CC=CC=C2
Properties [1]
C12H13NO2S
Molar mass 235.3
AppearanceOff-white solid
Density 1.45 g/cm3
Melting point 91.5°C
134 mg/L
log P 2.3
Hazards
GHS labelling: [2]
GHS-pictogram-exclam.svg GHS-pictogram-silhouette.svg GHS-pictogram-pollu.svg
Warning
H317, H373, H410
P260, P261, P272, P273, P280, P302+P352, P319, P321, P333+P313, P362+P364, P391, P501
Related compounds
Related compounds
Oxycarboxin
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Carboxin is a narrow-spectrum fungicide used as a seed treatment in agriculture to protect crops from fungal diseases. It was first marketed by Uniroyal in 1969 using their brand name Vitavax. The compound is an anilide which combines a heterocyclic acid with aniline to give an inhibitor of succinate dehydrogenase (SDHI). [1] [3]

Contents

Synthesis

The first synthesis of carboxin was disclosed in patents filed by Uniroyal. [4]

Carboxin synthesis.svg

Ethyl 2-chloroacetoacetate is treated with 2-mercaptoethanol and base, followed by cyclisation and water removal under acidic conditions. The resultant ethyl ester of the 1,4-oxathiine heterocycle is then formed into an amide with aniline using standard conditions via the carboxylic acid and acid chloride. This gives carboxin in high overall yield. [5] The compound has been crystallised in two polymorphic forms, [6] which have equal biological activity. [7]

Mechanism of action

The mechanism of action of carboxin was not established until several years after it was first reported in 1966. In the period 1971–1975, evidence grew that it acted by inhibition of succinate dehydrogenase (SDHI), [8] and later work showed that it binds to the quinone reduction site of the enzyme complex, preventing ubiquinone from doing so. As a consequence, the tricarboxylic acid cycle and electron transport chain cannot function. [9] [10]

The compound was an early example of a fungicide exhibiting systemic movement from its application site on the crop plant to protect newly-growing tissue. [6]

Usage

Owing to its systemic properties, carboxin is suitable for use as a seed treatment to give fungal control on the growing crop. However, it controls a relatively narrow range of species: mainly Tilletia spp. (known as bunts and smuts) in cereal crops and Rhizoctonia in cotton and vegetables. [3] [7]

The compound was used in Australia, the EU, the UK and the US but registration has lapsed in the EU. [1] . It was reported to have had a total worldwide sales of $75 million in 2014. [3] :405

Human safety

Carboxin has low mammalian toxicity and is not persistent in the environment. [1] [11] One of its metabolites, the sulfone, is also active as an SDHI and has been sold as the fungicide oxycarboxin. [12]

Analogues

Carboxin was the first SDHI-type fungicide and its invention triggered a search for compounds with improved properties, particularly for active ingredients which would control a broader range of economically-important diseases. [13] Boscalid, introduced in 2003, retained the aniline amide part-structure but with a pyridine ring in place of the 1,4-oxathiine and with a second benzene ring attached to the aniline portion. By 2014, it had annual sales of $390 million. [3]

As of 2023, over 18 related amides had been marketed, with seven of these being derivatives of 3-(Difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid. [14] The Fungicides Resistance Action Committee (FRAC) [15] assigns fungicides into classes so as to facilitate resistance management and SDHI form one group. [16]

Brands

Carboxin is the ISO common name [17] for the active ingredient which is formulated into the branded product sold to end-users. Vitavax is the brand name originally used by Uniroyal but as the compound's patents expired it became available to many other manufacturers and has been sold under multiple names. [1] [7]

Related Research Articles

<span class="mw-page-title-main">Amide</span> Organic compounds of the form RC(=O)NR′R″

In organic chemistry, an amide, also known as an organic amide or a carboxamide, is a compound with the general formula R−C(=O)−NR′R″, where R, R', and R″ represent any group, typically organyl groups or hydrogen atoms. The amide group is called a peptide bond when it is part of the main chain of a protein, and an isopeptide bond when it occurs in a side chain, such as in the amino acids asparagine and glutamine. It can be viewed as a derivative of a carboxylic acid with the hydroxyl group replaced by an amine group ; or, equivalently, an acyl (alkanoyl) group joined to an amine group.

Fungicides are pesticides used to kill parasitic fungi or their spores. They are most commonly chemical compounds, but may include biocontrols and fungistatics. Fungi can cause serious damage in agriculture, resulting in critical losses of yield, quality, and profit. Fungicides are used both in agriculture and to fight fungal infections in animals. Fungicides are also used to control oomycetes, which are not taxonomically/genetically fungi, despite their large differences in method of plant invasion. Fungicides can either be contact, translaminar or systemic. Contact fungicides are not taken up into the plant tissue and protect only the plant where the spray is deposited. Translaminar fungicides redistribute the fungicide from the upper, sprayed leaf surface to the lower, unsprayed surface. Systemic fungicides are taken up and redistributed through the xylem vessels. Few fungicides move to all parts of a plant. Some are locally systemic, and some move upward.

<span class="mw-page-title-main">Malonic acid</span> Carboxylic acid with chemical formula CH2(COOH)2

Malonic acid (IUPAC systematic name: propanedioic acid) is a dicarboxylic acid with structure CH2(COOH)2. The ionized form of malonic acid, as well as its esters and salts, are known as malonates. For example, diethyl malonate is malonic acid's diethyl ester. The name originates from the Greek word μᾶλον (malon) meaning 'apple'.

<span class="mw-page-title-main">Succinate dehydrogenase</span> Enzyme

Succinate dehydrogenase (SDH) or succinate-coenzyme Q reductase (SQR) or respiratory complex II is an enzyme complex, found in many bacterial cells and in the inner mitochondrial membrane of eukaryotes. It is the only enzyme that participates in both the citric acid cycle and the electron transport chain. Histochemical analysis showing high succinate dehydrogenase in muscle demonstrates high mitochondrial content and high oxidative potential.

Pyrazole is an organic compound of azole group with the formula C3H3N2H. It is a heterocycle characterized by a 5-membered ring of three carbon atoms and two adjacent nitrogen atoms, which are in ortho-substitution. Pyrazole is a weak base, with pKb 11.5 (pKa of the conjugate acid 2.49 at 25 °C). Pyrazoles are also a class of compounds that have the ring C3N2 with adjacent nitrogen atoms. Notable drugs containing a pyrazole ring are celecoxib (celebrex) and the anabolic steroid stanozolol.

The cereal grain wheat is subject to numerous wheat diseases, including bacterial, viral and fungal diseases, as well as parasitic infestations.

<span class="mw-page-title-main">Anilide</span> Organic compounds of the form RC(=O)N(R’)C₆H₅

In organic chemistry, anilides are a class of organic compounds with the general structure R−C(=O)−N(−R’)−C6H5. They are amide derivatives of aniline.

Acibenzolar-<i>S</i>-methyl Chemical compound

Acibenzolar-S-methyl is the ISO common name for an organic compound that is used as a fungicide. Unusually, it is not directly toxic to fungi but works by inducing systemic acquired resistance, the natural defence system of plants.

<span class="mw-page-title-main">Azoxystrobin</span> Chemical compound

Azoxystrobin is a broad spectrum systemic fungicide widely used in agriculture to protect crops from fungal diseases. It was first marketed in 1996 using the brand name Amistar and by 1999 it had been registered in 48 countries on more than 50 crops. In the year 2000 it was announced that it had been granted UK Millennium product status.

<span class="mw-page-title-main">Saflufenacil</span> Chemical compound

Saflufenacil is the ISO common name for an organic compound of the pyrimidinedione chemical class used as an herbicide. It acts by inhibiting the enzyme protoporphyrinogen oxidase to control broadleaf weeds in crops including soybeans and corn.

Early twenty-first century pesticide research has focused on developing molecules that combine low use rates and that are more selective, safer, resistance-breaking and cost-effective. Obstacles include increasing pesticide resistance and an increasingly stringent regulatory environment.

<span class="mw-page-title-main">Fluxapyroxad</span> Chemical compound

Fluxapyroxad is a broad-spectrum pyrazole-carboxamide fungicide used on a large variety of commercial crops. It stunts fungus growth by inhibiting the succinate dehydrogenase (SQR) enzyme. Application of fluxapyroxad helps prevent many wilts and other fungal infections from taking hold. As with other systemic pesticides that have a long chemical half-life, there are concerns about keeping fluxapyroxad out of the groundwater, especially when combined with pyraclostrobin. There is also concern that some fungi may develop resistance to fluxapyroxad.

<span class="mw-page-title-main">Fluopyram</span> Chemical compound

Fluopyram is a fungicide and nematicide used in agriculture. It is used to control fungal diseases such as gray mold (Botrytis), powdery mildew, apple scab, Alternaria, Sclerotinia, and Monilinia. It is an inhibitor of succinate dehydrogenase.

<span class="mw-page-title-main">Tebufenpyrad</span> Chemical compound

Tebufenpyrad is an insecticide and acaricide widely used in greenhouses. It is a white solid chemical with a slight aromatic smell. It is soluble in water and also in organic solvents.

<span class="mw-page-title-main">Oxycarboxin</span> Chemical compound

Oxycarboxin is an organic chemical used in agriculture to protect crops from fungal diseases. It was first marketed by Uniroyal in 1969 using their brand name Plantvax. The compound is an anilide which combines a heterocyclic acid with aniline to give an inhibitor of succinate dehydrogenase (SDHI).

<span class="mw-page-title-main">Sedaxane</span> Chemical compound

Sedaxane is a broad spectrum fungicide used as a seed treatment in agriculture to protect crops from fungal diseases. It was first marketed by Syngenta in 2011 using their brand name Vibrance. The compound is an amide which combines a pyrazole acid with a substituted aniline to give an inhibitor of succinate dehydrogenase.

<span class="mw-page-title-main">Fomesafen</span> PPOi herbicide

Fomesafen is the ISO common name for an organic compound used as an herbicide. It acts by inhibiting the enzyme protoporphyrinogen oxidase (PPO) which is necessary for chlorophyll synthesis. Soybeans naturally have a high tolerance to fomesafen, via metabolic disposal by glutathione S-transferase. As a result, soy is the most common crop treated with fomesafen, followed by other beans and a few other crop types. It is not safe for maize/corn or other Poaceae.

<span class="mw-page-title-main">Pydiflumetofen</span> Chemical compound used to kill fungi

Pydiflumetofen is a broad spectrum fungicide used in agriculture to protect crops from fungal diseases. It was first marketed by Syngenta in 2016 using their brand name Miravis. The compound is an amide which combines a pyrazole acid with a substituted phenethylamine to give an inhibitor of succinate dehydrogenase.

3-(Difluoromethyl)-1-methyl-1<i>H</i>-pyrazole-4-carboxylic acid Chemical compound

3-(Difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid is a chemical compound which is used commercially as an intermediate to seven fungicides which act by inhibition of succinate dehydrogenase (SDHI). It consists of a pyrazole ring with difluoromethyl, methyl and carboxylic acid groups attached in specific positions.

References

  1. 1 2 3 4 5 Pesticide Properties Database (2023-07-21). "Carboxin". University of Hertfordshire. Retrieved 2023-08-03.
  2. "GHS Classification". pubchem.ncbi.nlm.nih.gov. 2023-07-29. Retrieved 2023-08-03.
  3. 1 2 3 4 Walter, Harald (2016). "Fungicidal Succinate-Dehydrogenase-Inhibiting Carboxamides". In Lamberth, Clemens; Dinges, Jürgen (eds.). Bioactive Carboxylic Compound Classes: Pharmaceuticals and Agrochemicals. Wiley. pp. 405–425. doi:10.1002/9783527693931.ch31. ISBN   9783527339471.
  4. USpatent 3249499,von Schmeling, B.; Kulka, M.& Thiara, D.S.et al.,"Control of plant diseases",issued 1966-05-03, assigned to United States Rubber Co
  5. von Schmeling, B.; Kulka, Marshall (1966). "Systemic Fungicidal Activity of 1,4-Oxathiin Derivatives". Science. 152 (3722): 659–660. Bibcode:1966Sci...152..659V. doi:10.1126/science.152.3722.659. PMID   17779512. S2CID   27561137.
  6. 1 2 Frampton, Christopher S.; Frampton, Eleanor S.; Thomson, Paul A. (2018). "Two polymorphic forms of the oxathiin systemic fungicide active carboxine". Acta Crystallographica Section e Crystallographic Communications. 74 (12): 1741–1745. doi:10.1107/S2056989018015451. PMC   6281101 . PMID   30574366.
  7. 1 2 3 Worthing C.R., ed. (1987). The Pesticide Manual - A World Compendium (Eighth ed.). British Crop Protection Council. pp. 136–7. ISBN   0948404019.
  8. Gunatilleke, I. A. U. N.; Arst, H. N.; Scazzocchio, C. (1975). "Three genes determine the carboxin sensitivity of mitochondrial succinate oxidation in Aspergillus nidulans". Genetical Research. 26 (3): 297–305. doi:10.1017/S0016672300016098. PMID   178574.
  9. Oyedotun, Kayode S.; Lemire, Bernard D. (2004). "The Quaternary Structure of the Saccharomyces cerevisiae Succinate Dehydrogenase". Journal of Biological Chemistry. 279 (10): 9424–9431. doi: 10.1074/jbc.M311876200 . PMID   14672929.
  10. Avenot, Hervé F.; Michailides, Themis J. (2010). "Progress in understanding molecular mechanisms and evolution of resistance to succinate dehydrogenase inhibiting (SDHI) fungicides in phytopathogenic fungi". Crop Protection. 29 (7): 643–651. doi:10.1016/j.cropro.2010.02.019.
  11. "Reregistration Eligibility Decision (RED) Fact Sheet for Carboxin". EPA. 2004.
  12. Pesticide Properties Database (2023-06-15). "Oxycarboxin". University of Hertfordshire. Retrieved 2023-08-07.
  13. Yoshikawa, Yukihiro; Katsuta, Hiroyuki; Kishi, Junro; Yanase, Yuji (2011). "Structure-activity relationship of carboxin-related carboxamides as fungicide". Journal of Pesticide Science. 36 (3): 347–356. doi:10.1584/jpestics.G10-70. S2CID   85347084.
  14. Umetsu, Noriharu; Shirai, Yuichi (2020). "Development of novel pesticides in the 21st century". Journal of Pesticide Science. 45 (2): 54–74. doi:10.1584/jpestics.D20-201. PMC   7581488 . PMID   33132734.
  15. "Fungicides Resistance Action Committee website".
  16. "Search Fungicides to find FRAC Recommendations". Fungicides Resistance Action Committee. Retrieved 2023-08-03.
  17. "Compendium of Pesticide Common Names: Carboxin". BCPC. Retrieved 2023-08-07.