IR and Raman Spectra Studies of Rotundine Based on DFT
LI Jun-ping, ZHOU Guang-ming*, ZHANG Li-jun, CHENG Hong-mei, QIN Hong-ying
Key Laboratory on Luminescence and Real-Time Analysis(Southwest University), Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China
Abstract：Infrared spectroscopy (IR), the normal Raman spectroscopy (NRS) and the surface enhanced Raman spectroscopy (SERS) in new Ag/Cu nanomaterial of Rotundine were studied in the present paper. The IR and the NRS of Rotundine were calculated by the density functional theory (DFT) using B3LYP/6-311+G(d,p), then the spectral intensity graph of Rotundine were given. The vibrational peaks were assigned comprehensively by the visualization software of Gauss view 5.0. Rotundine has obvious infrared and Raman vibrational peak in the wave number range of 3 300～2500 and 1 800～600 cm-1. SnCl2 and PVP was used as capping agent for the silver nanoparticles in SERS of Rotundine. Finally, by using the method of cyclic immersion well dispersed silver nanoparticles was obtained and achieved good enhancement effect. This molecule acquired strong selective enhancement vibration peak, In the wave number ranges of 1 500～1 400 and 1 000～700 cm-1 the enhancement effect is most obvious. After analyzed, the methylene of this molecule is adsorbed on the silver nanoparticles surface and the angle between the benzene ring and the silver substrate is close to 90°. The theoretically calculated spectra of Rotundine are consistent with the obtained experimental spectra. There are some differences may be due to the interaction forces between molecules and so on. The visualization software displayed the structure characteristics and molecular group vibration of this molecular visually and provided important basis for assigning the vibrational peaks. Rotundine is an important traditional Chinese medicine agent contained in many kinds of sedative drugs. The study provides a strong basis for the rapid, feature and trace identification of Rotundine and also supplies important reference for the biological role of central inhibition of analgesic drugs.
[1] SHA Shi-yan, XU Li(沙世炎，徐 礼). Assay Methods for Active Components in Chinese Herb Medicines(中药有效成分分析方法). Beijing: People’s Medical Publishing House(北京：人民卫生出版社), 1985. 53. [2] Li C W, Zhang S, Gao H Q, et al. Eur. J. Drug. Metab Pharmacokinet, 2011, 36: 257. [3] YANG Ling-xia, WANG Lang-xia, ZHANG Bo-chong(杨玲霞, 王兰霞, 张伯崇). Chinese Traditional Patent Medicine(中成药), 2001, 23(12): 869. [4] LI Hui-min, FANG Can, HE Jing(李慧敏, 方 灿, 何 静). Central South Pharmacy(中南药学), 2008, 6(3): 379. [5] YANG Ming-li, QIAN Gang, LUO Su-yuan(杨明理，钱 刚，罗素元). Pharmacology and Clinics of Chinese Materia Medica(中药药理与临床)，2012, 28(1): 59. [6] Wang J B, Mantsch J R. Future Medicinal Chemistry, 2012, 4(2): 177. [7] Podstawka-Proniewicz E, Piergies N, Skozuba D, et al. J. Phys. Chem. A, 2011, 115: 11067. [8] Tian S, Zhou Q, Li C H, et al. J. Phys. Chem. C, 2013, 117: 556. [9] Xiao H J, Min Y, Yan J M, et al. American Chemical Society, 2013, 5: 6902. [10] Gao S M, Wang H Y, Zhang B M, et al. Journal of Molecular Structure, 2013, 1038: 95. [11] Mehmet K, Leena S, Onkar P, et al. Spectrochimica Acta Part A, 2012, 93: 33. [12] Lee C, Yang W, Parr R G. Phys. Rev. B, 1988, 37: 785. [13] Jiang X H, Lai Y C, Yang M, et al. Analyst, 2012, 137: 3996. [14] Leona M, Lombardi J R. Journal of Raman Spectroscopy, 2007, 38: 855.
