关键词: 光谱学, 太赫兹, 时域光谱, 吸收谱, 鞣花酸, 密度泛函理论

Abstract:

Ellagic acid is a polyphenol found in many species of plants. In resent years, more and more experiments have demonstrated that the Ellagic acid It plays an impotent role in inhibiting proliferation and inducing apoptosis of cancer cell. The ellagic acid also has the effect of antioxidation and radioresistance. It has now been used in a lot of medicine and health products. Terahertz time-domain spectroscopy (THz-TDS) is a new coherent spectral technique based on the femtosecond laser technology. In this paper The spectral characteristics of ellagic acid in the range of 0.2-2.4 THz have been measured by THz-TDS. The vibration absorption spectrum of the single molecule between 0.2 and 2.4 THz is simulated based on the Density Functional Theory (DFT). The simulation is consistent well with the experimental result at 1.58 THz. The refractive index and absorbance spectra of the ellagic acid are obtained at room temperature. It is found that the ellgic acid has the spectral response to THz radiations in this frequency region, and shows abnormal dispersion and absorption peaks at 0.44, 0.73, 0.99, 1.26, 1.58, 1.87, 2.19THz. THz-TDS technology can be used in qualitative analysis of the ellgic acid. The results provided in this paper will be helpful for the inspection of medicines and foods.

Key words: spectroscopy, terahertz, time-domain spectroscopy, absorbance spectra, ellagic acid, density functional theory