Pyridine as insecticide

Pyridine is primarily used in the manufacture of the herbicides paraquat and diquat. The first stage in the production of the pesticide chlorpyrifos is to chlorinate pyridine. Pyridine is also used to create fungicides based on pyrithione. Antiseptics such as cetylpyridinium and laurylpyridinium, which may be synthesised from pyridine using the Zincke reaction, are widely used in dental and oral hygiene products. Because pyridine is alkylating chemically reactive, N-alkylpyridinium salts may be easily synthesised from the molecule. One such chemical is cetoylpyridinium chloride.

Pyridine in agrochemical development

Pyridine-based chemicals are widely used in agriculture as fungicides, insecticides/acaricides, herbicides, and other pesticides. Many pesticides now on the market were discovered through screening programmes that depended on trial-and-error testing, and new agrochemical development is not benefiting from in silico novel chemical compound identification/finding procedures in the same way that pharmaceutical research does.

Podophyllotoxin (PPT) as insecticide

Podophyllotoxin (PPT) has the potential to be a lead structure in semi-synthetic insecticides, and the presence of 4′-OCH3 in these derivatives is required to retain their insecticidal action. Furthermore, the insecticidal effects of PPT derivatives having a pyridine ring are greater than those of 4′-DMEP derivatives.

Piperidinium and morpholinium 3-cyanopyridinethiolates as insecticides

Ten distinct heterocyclic compounds were evaluated for insecticidal activities against the cowpea aphid, including piperidinium and morpholinium 3-cyanopyridinethiolates, and were shown to have variable degrees of toxicity against the pest.

The pyridine and pyrimidine families of herbicides have a strong selectivity for broadleaf plants.

Aminocyclopyrachlor

Grasslands designated as rangeland, grasslands held by private individuals, rights of way, roadside areas, and industrial zones.

Aminopyralid

Used for Wheat, maize, pasture, rangeland, CRP land, woodlands, rights of way, fallow, non-agricultural uncultivated zones, industrial areas, and more.

Clopyralid

Used for Grass (including sporting fields, golf courses, parks, and industrial areas), ornamental trees, rights of way, and wheat. Alfalfa, apples, asparagus, barley, cabbage, canola, cherries, corn, dry beans, fallow, pasture, peaches, pecans, spinach, strawberries, sugar beets, corn, and wheat.

Dithiopyr*

Used in Ornamental plants, rights of way, and non-crop areas such as lawns and sod farms, golf courses, athletic grounds, and industrial locations.

Fluroxypy

Used in Wheat, corn, oats, rye, sorghum, triticale, fallow, CRP land, industrial zones, rights of way, pasture, oats, onions, pome fruits, rice, rye, sorghum, and pome fruits (including residential lawns, recreational areas, ornamental lawns).

Picloram

One can grow barley, oats, wheat, pasture, fallow, woodlands, CRP land, rights of way, industrial areas, and fencerows/hedgerows.

Triclopyr

Land utilized for grazing, wood harvesting, or other similar uses, as well as rights of way and fencerows.

Biological activities of pyridine derivatives include antibacterial, anticancer, antioxidant, insecticidal, and many others. As a result, scientists all across the world have developed an interest in these compounds. The pyridine moiety is a structural component of neonicotinoids, which are currently the most widely used insecticides in the world due to their wide range of crop protection applications, high efficacy without cross-resistance to other insecticides, low mammalian toxicity, unique mode of action specific for nAChRs, and broad insecticidal spectra.

Pyridine Derivatives: Examples

There are different pyridine derivatives: N-morpholinium 7,7-dimethyl-3-cyano-4-(4′-nitrophenyl) -5-oxo-1,4,5,6,7,8-hexahydroquinoline-2-thiolate (1); sodium 5-acetyl-3-amino-4(4′methoxyphenyl) pyridine; sodium 5-acetyl-3-amino-4-(4′-methoxyphenyl) pyridine Piperidinium 5-acetyl-3-cyano-4-(4′-methoxyphenyl)-6-methylpyridine-2-thiolate (2), piperidinium 3,5-dicyano-2-oxo-4-spirocyclopentane-1,2,3,4-tetrahydropyridine-6-thiolate (3), piperidinium 5-acetyl-3-cyano-4-(4′-chlorophenyl)-6-methylpyr. According to the results of the bioassay, compound 1 has roughly four times the insecticidal activity of the typical pesticide acetamiprid. The remaining compounds studied had moderate to high aphidicidal activity.

A novel Approach towards Pyridine insecticide

The innovative GO and ZIF-67-based magnetic solid phase extraction (m-SPE) material was created to achieve rapid and effective analysis of praziquantel and pymetrozine residues in food. Because it is difficult to separate ZIF and GO components from solutions and their discharge may cause secondary environmental contamination, a magnetic porous nano-composite termed ZIF-67 loaded on sheet-like MGO@PDA was synthesised at room temperature using a straightforward technique. The poly-dopamine (PDA) layer might increase the material's hydrophilicity. The original properties of ZIF-67 and MGO were preserved in the resultant MGO@PDA@ZIF-67. Experiments were carried out to investigate the adsorbent material's XRD, VSM, TEM, SEM, TGA, XPS, and FTIR characteristics. Using HPLC, a modified solid-phase extraction (m-SPE) approach was developed to selectively concentrate the pyridine ring insecticides praziquantel and pymetrozine (HPLC). A research was undertaken to discover how adsorption works. The results showed that the new material exhibited maximum adsorption capacities of 22.68 and 24.27 mg g1 for praziquantel and pymetrozine, respectively. Praziquantel and pymetrozine were both successfully detected in vegetable samples, with recoveries and precisions ranging from 92.3% to 102.8 percent. Because of its simplicity of fabrication, high efficiency, and renewability, the proposed hydrophilic magnetic porous nano-composite is a prospective magnetic ZIF-67 material for multi-component system separation.

1,3,4-oxadiazole moiety for insecticidal activity

Synthesis and bioassay of trifluoromethyl pyridine derivatives containing a 1,3,4-oxadiazole moiety for insecticidal activity against Mythimna distinct and Plutella xylostella. The compounds' activity against the two pests varied from 0% to 100%; in practice, partial compounds displayed much higher activity against Plutella xylostella than commercial chlorpyrifos.

Imidacloprid pyridine derivative as insecticide

Imidacloprid is the most extensively used pesticide in the world. It was the first chloronicotinyl insecticide. At position 5 of imidacloprid derivatives, the pyridine ring was substituted with methyl, trifluoromethyl, and methoxycarbonyl. This was done as part of a study seeking for imidacloprid variants with unique insecticidal spectra.

Insecticidal activity of novel 6-methanesulfonyloxypyridine-2-carboxamides

The construction of a model that inspired the design and synthesis of novel 6-methanesulfonyloxypyridine-2-carboxamides resulted in insecticidal activity, low mammalian toxicity, and aquatic creature safety. It was discovered that amides derived from -branched amines (such as isopropyl and sec-butyl) were the most effective. Tests on laboratory-reared insects in a rice nursery box revealed insufficient control over the entire spectrum of Japanese hoppers to support further investigation into these substances.

Hexahydroimidazo [1,2-]pyridine as insecticide

Neonicotinoid analogues of hexahydroimidazo [1,2-]pyridine were modified at the 5-, 6-, and 7-positions and examined for insecticidal activities. The addition of a methyl or ethyl at position 7 boosted the insecticidal activities, but the addition of other substituents had the reverse effect. Modifications with methyl or ethyl at the 5-, 6-, or both the 6- and 7-positions were deleterious to activity. Surprisingly, adding methyl to the 7-position not only enhanced its insecticidal efficiency against pea aphids, but it also outperformed imidacloprid against the brown plant hopper, which is resistant to the latter.