IDENTIFICATION

Common name:    Validamycin

Iupac name:  1L-(1,3,4/2,6)-2,3-dihydroxy 6 hydroxymethyl-4-[(1S,4R, 5S,6S)-4,5,6 -trihydroxy-3-hydroxymethylcyclohex-2-enylamino]cyclohexylβ-D-glucopyranoside

Chemical abstracts name: [1S-(lα,4α,5β,6α)]-1,5,6-trideoxy-4-O-β-D-glucopyranosyl-5-(hydroxymethyl)-l-[[4,5,6-trihydroxy-3-(hydroxymethyl)-2 –cyclohexen-1-yl]amino]-D-chiro-inositol

Type: Fungicide

CAS RN: [37248-47-8]

M.F.: C₂₀H₃₅NO₁₃

Mol Wt: 497.5

 

Form (appearance): Colourless, odourless, hygroscopic powder.

M.P.: 130-135℃ (decomp.)

V.P.: Negligible at room temperature

Solubility.: Readily soluble in water. Soluble in methanol, dimethylformamide and dimethyl sulfoxide Slightly soluble in ethanol and acetone. Sparingly soluble in diethyl ether and ethyl acetate.

Stability: Stable at room temperature in neutral or alkaline media, but slightly unstable in acidic media.  / Specific rotation [α]²⁴_D＋110⁰ (water)

 

Formulation types: DP; DS; SL; Liquid.

Biochemistry: Inhibitor of trehalase, an enzyme which mediates the digestion of the carbohydrate trehalose and transport of glucose to the hyphals tips.

Mode of action: Non-systemic antibiotic with fungistatic action. Causes abnormal branching of the tips of the pathogen, followed by cessation of further development.

Uses: Control of Rhizoctonia solani in rice, potatoc vegetables, strawberries, tobacco, ginger and other crops; damping off diseases of cotton, rice and sugar beet, etc. Applied as a foliar spray, soil drench, seed dressing, or by soil incorporation, at 1.25-1.56 g/ha (liquid), 9-12 g/ha (DL formulation), and 0.090 mg/kg (DL or seed dressing).

 

Oral: Acute oral LD₅₀ for rats and mice >20000 mg/kg.

Skin and eye: Acute percutaneous LD₅₀ for rats >5000 mg/kg. Non-irritating to skin (rabbits). Nota skin sensitiser (guinea pigs).

Inhalation: LC₅₀ (4 h) for rats >5 mg/l air.

Noel: In 90 d feeding trials, rats receiving 1000 mg/kg diet and mice receiving 2000 mg/kg diet showed no ill-effects. In 2 y feeding trials, NOEL for rats was 40.4 mg/kg b.w. daily.

Toxicity: WHO (a.i.) III (Table 5); EPA (formulation) IV

 

Fish: LC₅₀ (72 h) for carp >40 mg/l.

Daphnia: LC₅₀ (24 h) for D. pulex >40 mg/l.

 

Animals: In animals, cleavage to glucose and an amine residue occurs.

Soil/Environment: Rapid microbial degradation in soil; DT₅₀ ≤5 h.