Abstract Copaiba oils (COP), Andiroba (AND) and Brazil nuts (CDB) have been studied in several areas of science, mainly due to the interest from the pharmacological and food industries. A rapid analysis by techniques such as Raman and Fourier Transform Infrared spectroscopy (FTIR) gives us information concerning thier molecular nature. Results of FTIR and Raman for COP, AND and CDB, show modes of vibrations linked to fatty acids (AFs) in the sample composition, whose structures are rich in C=O, C=C and C-H. The results suggest modes in the 800-2000 cm-1 and 2500-3000 cm-1 regions, which fit the general characteristics of the AFs, strongly associated with oleic, linoleic, and palmitic acids. COP presents a mode with an intense peak at 2800-3000 cm-1, just related to the copalic acid, that presents contributions of rings of carbon. Finally, the results were discussed with DFT calculations complementing those obtained by FTIR and Raman.

Polarized Raman spectra of L-arginine hydrochloride monohydrated single crystal in nine different scattering geometries of the two irreducible representations of factor group C2 were studied at room temperature. The experimental wavenumber values are compared with those obtained from ab-initio calculation and the assignment of the Raman bands to the respective molecular vibrations is also given. Finally, a discussion related to a previously reported phase transition undergone by L-arginine hydrochloride monohydrated single crystal at low temperature is furnished.

This paper describes the study of two alkaloids extracted from Pilocarpus Microphyllus (Rutaceae): pilosine and epiisopilosine. These substances have potential application in the treatment of several diseases. In this work FT-Raman and the FT-IR spectra of pilosine and epiisopilosine were investigated at 300 K. Vibrational wavenumber and wave vector have been predicted using density functional theory (B3LYP) calculations with the 6-31 G(d,p) basis set. A comparison with experiment, allowed us to assign most of the normal modes of the crystals.