FTIR studies and spectrophotometric analysis of natural antioxidants, polyphenols and flavonoids in Abutilon indicum (Linn) Sweet leaf extract

The present study was conducted to characterize various bioactive phytoconstituents in leaf aqueous extract of Abutilon indicum using FTIR and UV-Vis spectroscopy. Phytochemical profiling of leaf aqueous extract was carried out and the total phenolic compounds and flavonoids were determined spectrophotometrically following the standard methods. FTIR and UV-Vis profiles showed the presence of phenolic compound and flavonoids in leaf extract. The peaks at 304.0 nm and 278.0 nm in UVspectrum confirmed the flavonoids and their derivatives. In addition to this, FTIR peaks obtained at 2171.7, 1636.2, 1407.1, 1347.6, 1130.4, 1254.5, 1047.1 and 904.3 cm thereby confirming the presence of alcohol, phenol, alkanes, amino acids, aldehyde, aromatic compound, secondary alcohol, sulfur compounds, carboxylic acid, and amide groups in the extract. An intense peak observed at 3436.20 cm in FTIR spectra correspond to the OH group. A spectrophotometric analysis of leaf extract showed 7.28 ± 0.15 μg of total phenolic compound (TAE per mg of dry leaf) and 9.13 ± 0.32 μg of flavonoids (QE per mg of dry leaf). The results obtained in the present study produced the FTIR and UV-Vis spectrum profile of medicinally important plant A. indicum which is helpful to screen and isolate various important phytoconstituents which are used for different kind of biological activities depending on their medicinal applications in pharmaceutical industries by herbal drugs manufacturers. Quantitative analysis indicates the presence of an appreciable amount of phenolic and flavonoids content in leaves thus, this plant can be used as a potent natural phenolic antioxidant in the treatment of various oxidative stress related diseases.