Valifenalate is a carboxylic acid amide fungicide jointly developed by the Italian agrochemical company Isagro S.p.A. and ISEM S.r.l., a joint venture company of Chemtura in the Netherlands. It has strong systemic activity and high biological activity against Oomycete fungal pathogens. It plays a protective, therapeutic and eradicating role on the surface and body of plants. It is often used to treat fungal diseases caused by Oomycetes such as pepper blight, potato late blight, and grape downy mildew.
Product introduction
Product name: Valifenalate
Other names: Valiphenal
Chemical name: 3-(4-chlorophenyl)-3-[[(2S)-3-methyl-2-(prop-2-yloxycarbonylamino)butyryl]amino]propionic acid methyl ester
Molecular formula: C19H27ClN2O5
Molecular weight: 398.881
CAS NO. : 283159-90-0
Structural formula:
Solubility: In water: 2.41×10-2g/L (pH4.9–5.9), 4.55×10-2g/L (pH9.5–9.8) (both at 20±0.5℃). In n-heptane 2.55×10-2, in xylene 2.31, acetone 29.3, ethyl acetate 25.4, 1,2-dichloroethane 14.4, methanol 28.8 (all in g/L, 20±0.5°C ).
Stability: Rapidly degrades in the air, atmospheric DT50 is stable in aqueous solution (pH 4) for 7.5 hours; DT50 7.62 d (pH 7, 50°C), 4.15 d (pH 9, 25°C). Stable to sunlight in aqueous solutions.
Mechanism of action
Valifenalate is an amino acid ester derivative fungicide with a unique new bionic structure, which makes its mechanism of action different from other fungicides used to control Oomycetes. Can affect all growth stages of oomycetes, including zoospore release and swimming, ascospore germination, hyphal growth, and spore formation. Specifically, it acts on the synthesis of fungal cell walls and proteins, inhibiting the infection and germination of spores, and at the same time inhibiting the growth of mycelium, causing it to deform and die. It has a good treatment and eradication effect on diseases caused by Peronospora and Phytophthora fungi, as well as oomycete diseases. It is worth noting that the International Action Committee on Fungicide Resistance classifies it into the CAA-fungicide group. Cross-resistance exists among varieties in the CAA-fungicide group, and attention should be paid to rotation and mixed use.
Application scope
Application: Often used to control oomycete diseases. Such as melon downy mildew, grape downy mildew, pepper blight, lychee downy mildew, onion downy mildew, lettuce downy mildew, potato and tomato late blight and tobacco black stem disease.
Common dosage forms: Original drug: 98%. Mixture: 66% water dispersant (containing 6% valifenalate + 60% mancozeb)
Product advantages
1. Outstanding protective and therapeutic effect, resistant to rain erosion, valifenalate can quickly and tightly combine with the waxy layer of leaves and penetrate into the plant tissue. It can reach the effective concentration after 2 hours and maintain it for 14 days.
2. Acting on multiple stages of disease occurrence, valifenalate has excellent permeability and partial systemic properties, and has both protective and therapeutic effects.
3. An effective tool for resistance management, it is still effective for strains resistant to benzamide fungicides.
4. It has good safety. It is still safe in the seedling stage of crops at the recommended dosage. It can also be used during the flowering stage. It has good compatibility with common fungicides.
Compound recommendation
Valifenalate + picoxystrobin: used to prevent and treat diseases caused by pathogenic bacteria of the class Oomycetes, Ascomycetes and Deuteromycetes. For example, when used to control lychee downy blight and watermelon anthracnose, it has a good effect on delaying the resistance of pathogenic bacteria.
Valifenalate + pyrimethanamine: used to control cucumber gray mold and lettuce sclerotinia, with obvious synergistic effect.
Valifenalate+Procymidide: used to prevent and control sclerotinia, gray mold, scab, brown rot, and large spot on fruit trees, vegetables, flowers, etc.
Valifenalate + Valifenalate: can be used to prevent and control various oomycete diseases such as downy mildew, late blight, etc. on vegetables, fruit trees, flowers and other crops.
Valifenalate+fluopicolin: has high control activity against pepper blight, potato late blight and various types of downy mildew.
Valifenalate+dimethomorph+propamocarb: the three-way compound has a significant synergistic effect on downy mildew. In actual use, it has good control effects on cucumber downy mildew and grape downy mildew.
Cyfenazole + Valifenalate: used for downy mildew on cucumbers and grapes, and late blight on potatoes and peppers.
Synthetic Route
The synthesis of Valifenalate mainly focuses on the synthesis of two key intermediates.
(1) Synthesis of methyl 3-amino-3-(4-chlorophenyl)propionate
(2) Synthesis of N-isopropoxycarbonylvaline-isopropoxyformate
(3) Synthesis of Valifenalate
Outlook
Limited by cost and production capacity, valifenalate is currently only promoted on high-value cash crops, such as grapes, tomatoes, and other vegetables. In addition, valifenalate has yet to be further developed in its potential in agriculture.
