Design and Synthesis of Hapten for Difenoconazole

Difenoconazole is a member of fungicides with broad-range activity. The compound protects quality and yield by seed treatment or foliar fertilizer application. Difenoconazole offers curative and long-lasting activity against Ascomycete, Basidiomycete, and Deuteromycete genera. A hapten is a certain small molecule that can stimulate antibody production only when conjugated to a larger biomolecule (termed a carrier). As a leading provider in hapten development projects, Creative Biolabs helps clients to simplify their way to design and synthesize ideal and stable hapten molecules with advanced technology platforms.

Introduction to Difenoconazole

Difenoconazole is a member of the family of dioxolanes that is 1,3-dioxolane replaced by 2-chloro-4-(4-chlorophenoxy)phenyl and 1,2,4-triazol-1-ylmethyl groups, at position 2. It is a broad-spectrum fungicide with new wide-range activity served as a spray or seed treatment. The difenoconazole molecule has moderate toxicity to humans, mammals, birds, and most aquatic animals. The compound takes a part as an environmental contaminant, an antifungal agrochemical, a sterol 14alpha-demethylase inhibitor, and a xenobiotic. It is a member of triazoles, an aromatic ether, a dioxolane, a cyclic ketal, as well defined as a conazole fungicide and a triazole fungicide. As difenoconazole holds 2 chiral centers, it exists in 4 stereoisomeric forms. In terms of the differences in their molecular configurations the stereoisomers of chiral pesticides are likely to differ in their binding to naturally occurring chiral molecules and structure-sensitive biological receptors.

The chemical structure of difenoconazole. Fig.1 The chemical structure of difenoconazole.

Hapten Design &Synthesis Services at Creative Biolabs

Difenoconazole is a 1,2,4-triazole fungicide exploited for the control of fungal diseases on fruits, vegetables, and other field crops. The compound acts by inhibition of demethylation during ergosterol synthesis and has been synthesized as a novel demethylation inhibitor fungicide. It has preventive and curative action and is widely used for its great fast-acting and excellent systemic activity.

Immunological detections based on antigen-antibody interaction have many prominent characteristics, including rapid, accurate, sensitive and high-throughput capacities. They have been successfully implemented in identifying small molecular contaminations in foodstuffs and play an essential role in food safety regulation. At Creative Biolabs, our experts have prepared high-specificity hapten and corresponding anti-hapten antibodies for the detection of difenoconazole.

Synthetic schemes of hapten 1 and hapten 2. Fig.2 Synthetic schemes of hapten 1 and hapten 2. (Xu, 2019)

Example of Hapten Design &Synthesis

To develop an indirect, competitive enzyme-linked immunosorbent assay, we have designed and synthesized two haptens of difenoconazole. The synthetic reactions to difenoconazole hapten 1 and hapten 2 have been illustrated in Fig.2. Among them, hapten 1 has a special moiety of difenoconazole, while hapten 2 has its overall structure. The crude products are extracted and after removal of the solvent by vacuum, haptens are harvested as a white powder. The intermediate and end products would be identified by mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy. Finally, the polyclonal antibodies against hapten-protein conjugates have been produced by immunizing rabbits.

Besides, the cross-reactivities of antibodies for the other 11 triazole fungicides are all less than 0.1%, including azaconazole, bitertanol, diniconazole, epoxiconazole, flusilazole, flutriafol, myclobutanil, triadimenol, tebuconazole, triadimefon, and propiconazole. No cross-reactivity is observed with these triazole compounds, indicating that the antibodies display high specificity to difenoconazole. The antibody immunized from hapten 1 has a special group of difenoconazole (a substituted moiety) and the antibody is specific to this molecule.


  • Optimized technologies and multifaceted platforms for difenoconazole hapten design and synthesis
  • Trained technicians work one-to-one with customers to guarantee the progress and quality
  • Standard operation procedures and strict quality controls at the end of each stage

With a high reputation in antibody production, Creative Biolabs has advanced technology platforms and extensive experience in developing antibody molecules for various challenging targets including difenoconazole. We’d like to provide custom services for optimized hapten design and synthesis services to satisfy clients’ needs. If you’re interested in our services, please don’t hesitate to contact us or directly send us an inquiry.


  1. Xu, C.L.; et al. Food Immunoassay. FOOD SCI NUTR. 2019.
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