Elementary research on Mid-IR and Raman spectra of chiral biomolecular enantiomer D- and L-arabinoses

Both D-arabinose and L-arabinose, as chiral aldopentose enantiomers C5H 10 O 5 , possess a similar biomolecular structure. But the former is rare in nature and can only be prepared by artificial synthesis, and the latter is a common sugar. A simple chiral recognition of both monosaccharides by an effective method is needed. Here we show an elementary study on this normal vibration spectroscopy, i.e., mid-infrared (MIR) and Raman spectroscopy methods. Through comparing the high-precision MIR (4000–400 cm –1 ) and Raman (4000–50 cm –1 ) spectra of D- and L-arabinoses, to the best of our knowledge, we try our best to find out small but distinctive spectral bands. Our study shows that almost all vibrational bands observed in the MIR spectra of D/L-arabinose are hard to tell apart, so the normal MIR spectroscopic method cannot be used as an effective chiral recognition method. But the Raman spectral bands in the middle-frequency and low-frequency bands (1600–50 cm –1 ) have displayed some distinguishable differences, and therefore, the low-wavenumber Raman scattering spectral method would be used as an optional chiral recognition method.