Quantification of Plant Phenolics and Proline

Cai et al. [24 (link)] procedure was employed for the analysis of phenolics in soybean, sunflower, and fungal filtrate. Different concentrations (100, 200, 300, 500, 600, 700, and 900 mg/ml) of gallic acid (Sigma Aldrich) were used to construct a standard curve. For the determination of proline, the method of Bates et al. [25 (link)] was followed, but after some modifications. A standard curve was plotted against different concentrations (2, 4, 6, 8, and 10 μg/ml) of standard proline (Sigma Aldrich) and the OD was taken at 520 nm. For the analysis of total flavonoids, the method of Mervat et al. [26 ] was used. A standard curve was constructed by using different concentrations of pure quercetin (15, 30, 60, 120, 240, and 480 μg/ml, Sigma Aldrich) and the OD were taken at 415 nm.