How a 1999 Patent Opened a New Front in Crop Protection
August 31, 1999
Few documents have the power to shape our world as quietly as a patent. Tucked away in archives with dry, legalistic language, they often contain breakthroughs that safeguard global food supplies. The United States Patent 5,945,567, granted to Curtze et al. on August 31, 1999, represents one such quiet revolution—a novel fungicidal compound that promised to protect crops from devastating fungal diseases in an era increasingly seeking alternatives to toxic chemical treatments.
While often overlooked, pathogenic fungi pose a constant threat to global agriculture and human health. These microscopic organisms destroy more than $1 billion worth of crops annually worldwide . From the Ug99 wheat stem rust that emerged in 1999—capable of devastating entire wheat harvests—to various fungi that attack fruits, vegetables, and other staple crops, the battle against fungal diseases is relentless .
Annual Crop Loss: $1+ billion
Major Threat: Ug99 wheat stem rust
Emergence: 1999
Scope: Worldwide impact
The late 1990s witnessed growing interest in developing more targeted, environmentally friendly fungicides. Research during this period explored everything from zosteric acid derived from eelgrass—which prevents fungal spores from attaching to plants without killing them—to various natural product alternatives to synthetic chemical fungicides 5 . This quest for effective, sustainable solutions formed the crucial backdrop against which patent 5,945,567 emerged.
The inventors, Curtze et al., addressed a fundamental challenge in fungicide development: creating compounds that effectively control fungal pathogens while minimizing environmental impact and resistance development. Their solution, as detailed in the patent, represents a class of 2-methoxybenzophenone derivatives with potent fungicidal properties 6 .
These compounds work through targeted biochemical action against essential fungal cellular processes. Unlike broad-spectrum fungicides that disrupt multiple organisms, these derivatives interfere with specific metabolic pathways unique to fungi, representing a more sophisticated approach to crop protection that was emerging in the late 1990s.
Patent No: 5,945,567
Inventors: Curtze et al.
Date: Aug 31, 1999
Compound: 2-methoxybenzophenone derivatives
The significance of this patent extends beyond its immediate application. It arrived alongside other agricultural innovations from the same period, including biofungicides that combined yeast with natural fibers like chitosan to protect fruits without synthetic chemicals 2 . This period marked an important transition toward developing fungicides that were both effective and environmentally considerate.
| Reagent Type | Specific Examples | Function in Research |
|---|---|---|
| Chemical Compounds | 2-methoxybenzophenone derivatives 6 , Zosteric acid 5 | Test substances for evaluating fungicidal activity |
| Natural Products | Chitosan 2 , Eelgrass extracts 5 | Provide natural alternatives to synthetic fungicides |
| Biological Agents | Candida saitoana yeast 2 | Act as biological competitors against pathogenic fungi |
| Surfactants & Carriers | Various polymers, Polyethylenimine 8 | Improve formulation stability and application efficacy |
| Analytical Standards | Purified compound samples 4 | Enable precise measurement and characterization |
While the specific laboratory procedures for patent 5,945,567 aren't detailed in the available literature, established testing methodologies from the same era provide insight into how such compounds were evaluated. Researchers typically followed a multi-stage process to assess efficacy, safety, and practical application.
The first stage involved synthesizing and purifying the 2-methoxybenzophenone derivatives described in the patent, followed by creating stable formulations often using polymers or other carriers to ensure consistent application 8 .
Scientists would then expose fungal cultures—such as those causing fruit rot or cereal rust—to various concentrations of the compound in petri dishes, measuring growth inhibition to establish preliminary efficacy 5 .
Promising compounds advanced to testing on live plants in controlled environments. Researchers would infect plants with fungal pathogens like strawberry rot organisms or wheat rust strains, then apply the experimental fungicide to assess protection under conditions mimicking real-world use 5 .
The most effective formulations underwent field testing across different geographical locations with varying climate conditions, crop varieties, and fungal pressure to evaluate performance in authentic agricultural settings .
Through biochemical assays and microscopic analysis, researchers determined exactly how the compound disrupted fungal processes—whether by preventing spore attachment, disrupting cell membranes, or interfering with metabolic pathways 5 .
| Treatment Type | Target Fungi | Efficacy | Advantages |
|---|---|---|---|
| 2-methoxybenzophenone derivatives | Various plant pathogens | High potency | Targeted action, potential reduced environmental impact |
| Zosteric acid | Strawberry fruit rot fungi | Prevents spore attachment | Non-toxic, resistance-averse 5 |
| Biofungicide (Chitosan + Yeast) | Post-harvest fruit fungi | Comparable to synthetics | Nontoxic, controls established infections 2 |
| Synthetic chemical fungicides | Broad spectrum | Variable | Immediate potency, but resistance development concerns |
The journey that began with patents like 5,945,567 continues today with increasingly sophisticated approaches. Researchers are now "stacking" multiple resistance genes into single wheat plants—deploying five different protective genes simultaneously to combat stem rust . This genetic approach, combined with advanced chemical solutions, represents our best hope for sustainable crop protection.
"The more you know your enemy, the more equipped you are to fight against it. Knowing how these pathogens come about means we can better predict how they are likely to change in the future."
Stacking multiple resistance genes in crops to create durable protection against evolving fungal pathogens.
Developing biofungicides from natural sources like plants and microorganisms for sustainable crop protection.
The story of fungicide development reminds us that scientific progress often builds quietly through incremental advances. Each patent, each discovery, each research paper adds another piece to the puzzle—another weapon in our ongoing battle against the microscopic enemies that threaten our food supply. And as fungi continue to evolve, so too must our ingenuity in countering them.