DefinePK

Research Objective

To synthesize 4-hydroxyazobenzene and evaluate its in vitro antifungal activity against the plant pathogen Macrophomina phaseolina.

Methodology

The study involved the synthesis of 4-hydroxyazobenzene through an azo coupling reaction between aniline diazonium salt and activated phenol. The antifungal activity was assessed in vitro by dissolving the synthesized compound in dimethyl sulfoxide (DMSO) and preparing serial dilutions in malt extract broth. Macrophomina phaseolina was cultured and inoculated into the prepared media. Fungal biomass was measured after incubation. Statistical analysis was performed using ANOVA and the LSD test.

Methodology Flowchart

                        graph TD
    A[Synthesis of 4-Hydroxyazobenzene] --> B[Preparation of Compound Solutions];
    B --> C[Preparation of Fungal Inoculum];
    C --> D[Inoculation of Media with Compound and Fungus];
    D --> E[Incubation];
    E --> F[Harvesting and Drying of Fungal Biomass];
    F --> G[Weighing of Fungal Biomass];
    G --> H[Statistical Analysis];
    H --> I[Conclusion on Antifungal Activity];                    

Discussion

The study suggests that 4-hydroxyazobenzene can be used for the control of Macrophomina phaseolina. The antifungal activity is attributed to the conjugated double bonds in azo dyes, which can interact with fungal cell membranes, leading to ion leakage and cell death. The results align with previous research on the antifungal properties of various azo dyes.

Key Findings

The synthesized 4-hydroxyazobenzene appeared as orange-yellow crystalline solid with a melting point of around 155°C. All tested concentrations (0.78 to 100 mg mL-1) of the compound significantly reduced the biomass of Macrophomina phaseolina by 31-49%.

Conclusion

4-Hydroxyazobenzene exhibits pronounced antifungal activity against Macrophomina phaseolina, with significant growth reduction observed across a range of concentrations. Further research is recommended to prepare derivatives of this compound to enhance its antifungal efficacy.

Fact Check

1. Concentration Range: The study evaluated concentrations of the synthesized compound ranging from 0.78 to 100 mg mL-1.
2. Biomass Reduction: All tested concentrations significantly reduced the biomass of M. phaseolina by 31-49%.
3. Melting Point: The synthesized 4-hydroxyazobenzene had a sharp melting point at around 155°C.

Mind Map