APPLICATION OF FTIR SPECTROSCOPY IN THE SCREENING OF FUNCTIONAL GROUPS PRESENT IN EXTRACT OF CAFERANA LEAVES

Infusions of caferana leaves (Bunchosia glandulifera) and roasted seeds are prepared to prevent cancer, Alzheimer's and neurodegenerative diseases, in addition to aid memory preservation. The tonic is consumed by indigenous people and residents of the northern regions of Rio Grande do Sul and southern Santa Catarina states aiming to restore physical strength, mental vigor, and promote psychological changes in religious rituals. Recent research in caferana leaf and seed extracts has found nitrogenous alkaloids such as trigonelline, harmaline, caffeine, and δ-lactam, in addition to essential amino acids, revealing that consumer perceptions may have a scientific basis. This study aimed to screen functional groups present in caferana leaf extract in an FTIR-ATR Cary 630 Agilent equipment. The extract was obtained by supercritical system with CO₂ at 250 bar and 60 ºC. The general assignment of the bands identified in spectra was: at 1715 cm^-1 a characteristic band of carbonyl stretching (nC=O) of cyclic amides or aryl esters;  at 1647 cm^-1 a compatible band with N-H bending or C=N stretching; the absorptions between 3000 and 2840 cm^-1 are characteristic of sp³ C-H stretching; at 1461 cm^-1 a band related to the CH₂ bending; at 1379 cm^-1 a band related to the CH₃ bending; the bands at 1267 and 1103 cm^-1 are correlated to the C-O stretching of aryl esters; the bands at 1267 and 1021 cm^-1 are characteristic of C-O-C asymmetric and symmetric stretching of alkyl aryl ethers, respectively; absorptions between 900 and 690 cm^-1 reveals out-of-plane =C-H bending, compatible with cyclic compounds with resonance in the aromatic rings. Therefore, through FTIR spectroscopy screening of the functional groups present in the caferana leaf extract, it is possible to detect the presence of compounds related to esters and nitrogenous alkaloids, as cited in the literature.