Comparative characterization of morphoanatomy, phytochemistry and thermal decomposition between two species of the genre Citronella (family: Cardiopteridaceae)

Abstract

This work describes the morphological, phytochemical and thermal characterization of the angiosperm species Citronella gongonha and Citronella paniculata, found in humid areas of the Atlantic Forest and in pan-tropical regions belonging to the Cardiopteridaceae family. For this study, extracts from both species were applied by thin layer chromatography. At the same time, histological sections and histochemical tests were carried out to analyze the morphology of the leaves, midvein and petiole of these species using optical microscopy. In addition, images of the sides of the leaves, details of the cuticle and stomata captured by Scanning Electron Microscopy (SEM). Finally, the thermal manipulation of the leaves of both species was analyzed, generating individualized TG/TGA curves for each of them. The morphoanatomical comparison revealed differences in the shape of the midrib and petiole between Citronella species. Regarding the phytochemical profile, there is a similarity between the two, presenting terpenes, tannins, flavonoids, phenolic compounds and coumarins. However, thermal analysis showed a lower rate of mass degradation for C. paniculata (8.92%) compared to C. gongonha (29.2%). Furthermore, the degradation of carbon residues and polymers was more significant in the species C. paniculata (30.96%) compared to C. gongonha (13.42%) These results unprecedented in the scientific literature, contribute substantially to the characterization of the genus Citronella, encouraging complementary studies to investigate the industrial potential of the species.