In recent years, the use of essential oils (EOs) derived from aromatic plants as low-risk insecticides has increased considerably owing to their popularity with organic growers and environmentally conscious consumers. EOs are easily produced by steam distillation of plant material and contain many volatile, low-molecular-weight terpenes and phenolics. The major plant families from which EOs are extracted include Myrtaceae, Lauraceae, Lamiaceae, and Asteraceae. EOs have repellent, insecticidal, and growth-reducing effects on a variety of insects. They have been used effectively to control preharvest and postharvest phytophagous insects and as insect repellents for biting flies and for home and garden insects. The compounds exert their activities on insects through neurotoxic effects involving several mechanisms, notably through GABA, octopamine synapses, and the inhibition of acetylcholinesterase. With a few exceptions, their mammalian toxicity is low and environmental persistence is short. Registration has been the main bottleneck in putting new products on the market, but more EOs have been approved for use in the United States than elsewhere owing to reduced-risk processes for these materials.

Essential oils in insect control: low-risk products in a high-stakes world.

Medicinal attributes of 1,2,3-triazoles: Current developments

Increased demand for food to feed the ever-growing population led to development and adoption of synthetic chemicals as a quick and effective strategy of managing crop pests and diseases. However, overreliance on synthetic pesticides is discouraged due to their detrimental effects on human health, the environment, and development of resistant pest and pathogen strains. This, coupled with increasing demand for organically produced foods, stimulated search for alternative approaches and botanical pesticides are particularly gaining importance. Botanical pesticides are efficacious in managing different crop pests, inexpensive, easily biodegraded, have varied modes of action, their sources are easily available and have low toxicity to non-target organisms. Their varied modes of action are attributed to the phytochemical composition in different plants. Therefore, they can be incorporated into integrated pest management systems and contribute to sustainable agricultural production. Nevertheless, botanical pesticides have not been fully adopted due to challenges in formulation and commercialization which are attributed to lack of chemical data and positive controls. Many publications have featured botanical pesticides with skewed interest towards management of insect pests. This review brings together information regarding botanical pesticides, their phytochemical composition and mechanisms of action against pests of importance in agricultural production. The paper also presents chemistry data of selected botanical pesticides, their biodegradation, role in integrated pest management and the challenges facing their adoption and utilization for sustainable crop pest management.

Phytochemical activity and role of botanical pesticides in pest management for sustainable agricultural crop production

The review lays emphasis on the significance of 1,2,3-triazoles synthesized via CuAAC reaction having potential to act as anti-microbial, anti-cancer, anti-viral, anti-inflammatory, anti-tuberculosis, anti-diabetic, and anti-Alzheimer drugs. The importance of click chemistry is due to its ‘quicker’ methodology that has the capability to create complex and efficient drugs with high yield and purity from simple and cheap starting materials. The activity of different triazolyl compounds was compiled considering MIC, IC50, and EC50 values against different species of microbes. In addition to this, the anti-oxidant property of triazolyl compounds have also been reviewed and discussed.

https://pubs.rsc.org/en/content/articlepdf/2020/RA/C9RA09510A

CuAAC-ensembled 1,2,3-triazole-linked isosteres as pharmacophores in drug discovery: review

Prevention of food losses during postharvest storage is of paramount economic importance. Integrated pest management is now a widely accepted strategy in pest control including postharvest infestation control which involves the use of chemical (contact/residual) insecticides along with fumigants. The use of synthetic chemical insecticides is either not permitted or used restrictively because of the residue problem and health risks to consumers. In view of the above, there is a need for plants that may provide potential alternatives to the currently used insect control agents as they constitute a rich source of bioactive molecules. Available literature indicates that plant could be source for new insecticides. Therefore, there is a great potential for a plant-derived insecticidal compounds. This paper focuses on the current state of the botanical insecticides as grain protectants and its mode of action.

/pdf/botanicals-as-grain-protectants-4wr37752d8.pdf

Botanicals as Grain Protectants

The increasing concern over the level of pesticide residues in food has encouraged researchers to look for alternatives of synthetic pesticides. Their indiscriminate use has led to the development of resistant strains of pests as well as different environmental and human health problems. Recently, in different parts of the world, attention has been paid towards exploitation of higher plant products as novel chemotherapeutants in plant protection. Because of non phytotoxicity, systemicity, easy biodegradability and stimulatory nature of host metabolism, plant products possess the potential in pest management. Used widely until the 1940’s, these natural pesticides were displaced by modern synthetic pesticides that at the time seemed cheaper, easier and long lasting. The popularity of botanical pesticides is once again increasing and some plant products are being used globally as green pesticides. The body of scientific literature documenting bioactivity of plant derivatives to different pests continues to expand, yet only a handful of botanicals are currently used in agriculture. Pyrethroids and neem products are well established commercially as botanical pesticides and recently some essential oils of higher plants have also been used as antimicrobials against storage pests because of their relatively safe status and wide acceptance by the consumers. Some of the volatile oils, which often contain the principal aromatic and flavouring components of herbs and spices, have been recommended as plant based antimicrobials to retard microbial contamination and reduction in spoilage of food commodities. Furthermore, some of the antimicrobial plant products also possess strong antioxidant activities which are favourable properties to combat free radical mediated organoleptic deterioration of plant commodities and enhancing their shelf life. In the context of agricultural pest management, botanical pesticides are best suited for use in organic food production in industrialized countries but can play a much greater role in the production and post harvest protection of food products in developing countries.

/pdf/current-status-of-plant-products-as-botanical-pesticides-in-49ld8vqyk3.pdf

Current Status of Plant Products as Botanical Pesticides in storage pest management

Clay-Supported Cu(II) Catalyst: An Efficient, Heterogeneous, and Recyclable Catalyst for Synthesis of 1,4-Disubstituted 1,2,3-Triazoles from Alloxan-Derived Terminal Alkyne and Substituted Azides Using Click Chemistry

The intensive use of synthetic pesticides and their environmental and toxicological risks have generated increased global interest to develop alternative sources of chemicals to be used in safe management of plant pests. Recently, in different parts of the world, attention has been paid towards exploitation of higher plant products as novel chemotherapeutics for plant protection because they are mostly non phytotoxic and easily biodegradable. Currently, different plant products have been formulated for large scale application as botanical pesticides in eco-friendly management of plant pests and are being used as alternatives to synthetic pesticides in crop protection. These products have low mammalian toxicity and are cost effective. Such products of higher plant origin may be exploited as eco-chemical and biorational approach in integrated plant protection programmes. The current status and future prospects of botanical pesticides in eco-friendly management of different plant pests are reviewed and discussed.

Exploitation of Natural Compounds in Eco-Friendly Management of Plant Pests

The present paper elicits an unprecedented synthesis of a novel series of 1,2,3-triazole compounds using geraniol as the precursor via 1,3-dipolar cycloaddition using click chemistry strategy. All the synthesized compounds were screened to evaluate their microbicidal and antioxidant potentials. The antibacterial activity of all the new compounds was assessed by the micro-broth dilution technique against a panel of Gram-positive Staphylococcus aureus (MTCC 3160), Bacillus cereus (MTCC 430), and Gram-negative Escherichia coli (MTCC 1610) and Pseudomonas aeruginosa (MTCC 2295). Furthermore, evaluation of their antioxidative behavior manifested the remarkable free radical scavenging activity using DPPH assay. Also, the docking study of the compounds was performed on complex structure of E.coli FabH (1HNJ. pdb) using VLife MDS 3.5 software. Significant dock score of 5g (−80.121 kcal/mol) in comparison with the standard ciprofloxacin (−88.263 kcal/mol) has been figured out upon molecular docking.

A click chemistry strategy to synthesize geraniol-coupled 1,4-disubstituted 1,2,3-triazoles and exploration of their microbicidal and antioxidant potential with molecular docking profile

A new strategy for the synthesis of 2-aminobenzimidazoles via a reaction of α-halogenated cyclohexanone with guanidine is reported. It provides a facile N-bromosuccinimide (NBS) mediated transition metal free, sustainable path for the synthesis of 2-substituted azoles. NBS along with the oxone promotes in situ halogenation of cyclohexanone, which in turn, when allowed to react with guanidine, afforded 2-aminobenzimidazoles (2-ABI). This eco-friendly protocol provides a competent laboratory synthesis method associated with significant advantages such as greater selectivity, cost-efficiency, mild reaction conditions, absence of chromatographic purification, clean reaction profile, and a simple work-up procedure to furnish high yields. The structures of all the synthesized compounds were confirmed on the basis of IR, 1H and 13C NMR, mass spectrometry, and elemental analyses data. In addition, we have also extended the scope of this strategy for obtaining 2-amino substituted benzoxazoles.

Nitin Dubey

Papers

Current Status of Plant Products as Botanical Pesticides in storage pest management

Clay-Supported Cu(II) Catalyst: An Efficient, Heterogeneous, and Recyclable Catalyst for Synthesis of 1,4-Disubstituted 1,2,3-Triazoles from Alloxan-Derived Terminal Alkyne and Substituted Azides Using Click Chemistry

Exploitation of Natural Compounds in Eco-Friendly Management of Plant Pests

A click chemistry strategy to synthesize geraniol-coupled 1,4-disubstituted 1,2,3-triazoles and exploration of their microbicidal and antioxidant potential with molecular docking profile

A new NBS/oxone promoted one pot cascade synthesis of 2-aminobenzimidazoles/2-aminobenzoxazoles: a facile approach