RHF and DFT studies of the vibrational spectra of the Glucosamine and some of its derivatives

A.K. Sharma, S.D.S. Chauhan, R. Kumar, D. Kulshreshtha, R. Gupta, P.K.S. Chauhanı and O.P. Singh²

Department of Physics, ıDepartment of Chemistry, Paliwal (P.G.) College, Shikohabad - 205 135 (India). ²Department of Physics, Udai Pratap Autonomous College Varanasi - 221 002 (India).

Received on August 08, 2009 and accepted on October 15, 2009

ABSTRACT

The vibrational frequencies for the fundamental modes and the low lying states of Glucosamine and its salts in gas phase have been calculated at RHF, DFT and RMP2 ab-initio level. The calculated vibrational frequencies, so obtained, have been compared with experimental observation of IR and RAMAN spectrum. It is found that glucosamine sulphate is more stable than other glucosamine salts taken for the present study. The relative red and blue shifts between glucosamine and its salts suggests that glucosamine sulphate is more reactive in body as compared to other salts and glucosamine itself and therefore, more helpful in reducing the pain by improving the mobility of joint-fluids in osteoarthritis, without any side effect.

Keywords : IR; Raman; Vibrational frequencies; RMP2/DFT; Glucosamine; Shifts.