Advances in Drug Discovery Research for Agrochemistry

In contemporary agriculture, the world's largest industry, agrochemistry plays a crucial role in achieving food security,enhancing agricultural productivity, ensuring crop protection from pests, weeds, fungi, and microbial pathogens (Fig. 1). Evidently relying on innovation, today’s agrochemistry is indispensable from advances in drug discovery focused on designing compounds for specific uses – whether to eliminate pests (insecticides), control unwanted plants (herbicides), or manage microbial pathogens and fungi (microbiocides and fungicides). Recent achievements in the development of these agrochemical agents have contributed to the overall stability of agricultural production, but also introduced serious concerns related to the resistance of living organisms aimed at and environmental sustainability.

Fig. 1. Agrochemicals: insecticides, herbicides, microbiocides, fungicides.
Examples from Life Chemicals screening libraries.

The latest successes in finding promising insecticides have relied heavily on high-throughput screening (HTS) technologies and combinatorial chemistry [1-3]. Coupled with breakthroughs in molecular biology, these approaches have enabled the identification and targeting of specific receptors and enzymes in pests, leading to the design of more selective insecticides with fewer off-target effects. However, insecticide resistance continues to pose a major hurdle in effective pest management. Mechanisms such as target-site mutations, enhanced metabolic detoxification, and behavioral adaptations among pests have reduced the efficacy of many traditional insecticides [4]. Addressing these challenges requires a multifaceted approach, combining the development of insecticides with new modes of action and the implementation of integrated pest management. The latter promotes rotating insecticides, reducing resistance and ensuring long-term pest control effectiveness.

The push for sustainable agriculture has also influenced insecticide development and has led to growing interest in natural insecticides. Neem-based products, derived from Azadirachta indica, are one such example of a natural insecticide that has shown promise in pest control while posing fewer environmental risks [5]. Other plant-derived compounds and microbial insecticides are being extensively explored as they may offer an eco-friendly alternative to synthetic chemicals and balance pest control with environmental protection [6,7].

Herbicides have long been crucial in controlling weeds, but the growing issue of resistance has obviously complicated their effectiveness. Recent advancements in herbicide discovery have centered on identifying novel biochemical targets within plants, such as inhibitors of auxin signaling and lipid biosynthesis [8]. Modern screening technologies, including the use of chlorophyll fluorescence assays, allow early identification of herbicide modes of action, facilitating the design of herbicides with unique biochemical targets [9].

However, herbicide resistance has become a widespread challenge, especially with the overuse of glyphosate and other broad-spectrum herbicides. Resistance mechanisms, such as metabolic detoxification and mutations in target sites, have rendered many traditional herbicides less effective. Developing herbicides with dual modes of action — targeting two biochemical pathways simultaneously — offers a potential solution to overcoming resistance, as it makes it more difficult for weeds to adapt to the herbicide [9]. Several novel herbicides, including synthetic auxins and acetolactate synthase inhibitors, have shown significant potential in managing resistant weed species [10]. These compounds work by exploiting different plant pathways, reducing the likelihood of resistance development and providing a more reliable and long-term solution for effective weed management.

Microbiocides (Fig. 2), used to control bacterial and viral pathogens in crops, are increasingly important in agrochemical research. Innovations in microbial control include the development of antimicrobial peptides, bacteriophages, and other biocidal agents that specifically target harmful microbes while sparing beneficial organisms [11]. These new microbiocides provide a targeted approach to pathogen control, improving crop health and yield.

Figure 2. Action mechanism of microbiocides [11].
Additionally, three microbiocide-analogues from Life Chemicals are presented.

However, the overuse of microbiocides has raised concerns about the development of antimicrobial resistance, which can compromise the efficacy of these agents. Certain microbiocides, when used extensively in agriculture, may contribute to the selection of resistant strains [12]. To mitigate this, combination treatments and the rotation of different microbiocides are used to lower the risk of resistance.

Fungal pathogens represent a significant threat to global food security, making the discovery of new fungicides crucial. The progress witnessed in molecular biology and HTS have revolutionized fungicide discovery [13]. Among the most effective classes of fungicides are sterol biosynthesis inhibitors and mitochondrial respiration blockers, both of which have been widely used in agriculture. However, resistance remains an ongoing challenge, limiting the long-term efficacy of these compounds [14].

Fungicide resistance is particularly problematic for widely used classes like strobilurins, where fungal populations can quickly develop resistance through mutations and other adaptive mechanisms. Resistance management strategies include the use of multi-target fungicides, which inhibit several fungal pathways simultaneously, reducing the likelihood of resistance evolving in fungal populations [15]. Several novel fungicides, including next-generation strobilurins and sterol inhibitors, have shown promise in controlling resistant fungal strains. These innovative compounds act through different mechanisms, offering a more robust solution to the ongoing problem of fungicide resistance, ensuring better crop protection and contributing to global food security.

The use of agrochemicals is not without environmental consequences. Pesticide runoff, soil contamination, and negative impacts on non-target species are significant concerns. To address these issues, new agrochemicals are being designed with improved environmental profiles, including reduced persistence in the environment and lower toxicity to non-target organisms. New compounds pass rigorous environmental safety tests before they can be approved for use, and the regulatory burden for agrochemical companies is growing [16]. This has prompted a shift toward more sustainable solutions that align with global environmental standards.

The future of agrochemical research lies in the development of sustainable, eco-friendly compounds that can meet the growing demand for crop protection while minimizing environmental impact. With an aim to drive innovation in this field, Life Chemicals created several compound libraries of agrochemical-like molecules, listed below:

AgroChemical Screening Libraries

• Insecticide Screening Library
• Herbicide Screening Library
• Microbiocide Screening Library
• Fungicide Screening Library
• Environmentally Toxic Compound Library

Notably, these sets are also available as pre-plated, ready-to-screen solutions for various agrochemical discovery projects.

In addition,there are special collections of chemical compounds for wider environmental research, including:

• Antifungal Screening Compound Library (Fig. 3).
• Biologically Active Compound Library
• Natural Product-like Compound Libraries
• Veterinary Focused Screening Library

Fig. 3. Representative screening compounds from the Antifungal Screening Compound Library.

Order your custom compound selections and enjoy the most convenient terms and competitive pricing.

Please, contact us at marketing@lifechemicals.com for any additional information and price quotations.

Download SD files with compound structures directly from our Downloads section

References

1.      Ridley, S. M., Elliott, A. C., Yeung, M., & Youle, D. (1998). High‐throughput screening as a tool for agrochemical discovery: automated synthesis, compound input, assay design and process management. Pestic. Sci., 54(4), 327-337. DOI: 10.1002/(SICI)1096-9063(199812)54:4%3C327::AID-PS828%3E3.0.CO;2-C

2.     Tietjen, K., Drewes, M., & Stenzel, K. (2005). High throughput screening in agrochemical research. Comb. Chem. High Throughput Screen., 8(7), 589-594. DOI: 10.2174/138620705774575300

3.     Drewes, M., Tietjen, K., & Sparks, T. C. (2012). High‐throughput screening in agrochemical research. In: Modern methods in crop protection research, 1-20. DOI: 10.1002/9783527655908

4.     Siddiqui, J. A., Fan, R., Naz, H., Bamisile, B. S., Hafeez, M., Ghani, M. I., et al. (2023). Insights into insecticide-resistance mechanisms in invasive species: Challenges and control strategies. Frontiers in Physiology, 13, 1112278. DOI: 10.3389/fphys.2022.1112278

5.     Boeke, S. J., Boersma, M. G., Alink, G. M., van Loon, J. J., van Huis, A., Dicke, M., & Rietjens, I. M. (2004). Safety evaluation of neem (Azadirachta indica) derived pesticides. J. Ethnopharmacol., 94(1), 25-41. DOI: 10.1016/j.jep.2004.05.011

6.     Turchen, L. M., Cosme-Júnior, L., & Guedes, R. N. C. (2020). Plant-derived insecticides under meta-analyses: status, biases, and knowledge gaps. Insects, 11(8), 532. DOI: 10.3390/insects11080532

7.      Khursheed, A., Rather, M. A., Jain, V., Rasool, S., Nazir, R., Malik, N. A., & Majid, S. A. (2022). Plant based natural products as potential ecofriendly and safer biopesticides: A comprehensive overview of their advantages over conventional pesticides, limitations and regulatory aspects. Microb. Pathog., 173, 105854. DOI: 10.1016/j.micpath.2022.105854

8.     Duke, S. O. (1990). Overview of herbicide mechanisms of action. Environ. Health Perspect., 87, 263-271. DOI: 10.1289/ehp.9087263

9.     Hassannejad, S., Lotfi, R., Ghafarbi, S. P., Oukarroum, A., Abbasi, A., Kalaji, H. M., & Rastogi, A. (2020). Early identification of herbicide modes of action by the use of chlorophyll fluorescence measurements. Plants, 9(4), 529. DOI: 10.3390/plants9040529

10.   Grzanka, M., Joniec, A., Rogulski, J., Sobiech, Ł., Idziak, R., & Loryś, B. (2024). Impact of novel herbicide based on synthetic auxins and ALS inhibitor on weed control. Open Life Sciences, 19(1), 20220868. DOI: 10.1515/biol-2022-0868

11.     Jones, I. A., & Joshi, L. T. (2021). Biocide use in the antimicrobial era: a review. Molecules, 26(8), 2276. DOI: 10.3390/molecules26082276

12.    Maillard, J. Y., Bloomfield, S., Coelho, J. R., Collier, P., Cookson, B., Fanning, S., et al. (2013). Does microbicide use in consumer products promote antimicrobial resistance? A critical review and recommendations for a cohesive approach to risk assessment. Microb. Drug Resist., 19(5), 344-354. DOI: 10.1089/mdr.2013.0039

13.    Calderone, R., Sun, N., Gay-Andrieu, F., Groutas, W., Weerawarna, P., Prasad, S., et al. (2014). Antifungal drug discovery: the process and outcomes. Future microbiol., 9(6), 791-805. DOI: 10.2217/fmb.14.32

14.    Steinberg, G., & Gurr, S. J. (2020). Fungi, fungicide discovery and global food security. Fungal Genet. Biol., 144, 103476. DOI: 10.1016/j.fgb.2020.103476

15.    Feng, Y., Huang, Y., Zhan, H., Bhatt, P., & Chen, S. (2020). An overview of strobilurin fungicide degradation: current status and future perspective. Front. microbiol. 11, 389. DOI: 10.3389/fmicb.2020.00389

16.    Jeschke, P., Krämer, W., Schirmer, U., & Witschel, M. (Eds.). (2013). Modern methods in crop protection research. John Wiley & Sons. ISBN: 978-3-527-33175-8