Estudo farmacognóstico diferencial entre as espécies capim santo (Cymbopogon citratus (DC) Stapf) e capim citronela (Cymbopogon winterianus Jowitt ex Bor)

Abstract

Capim-santo (Cymbopogon citratus) and Capim-citronela (Cymbopogon winterianus) are species belonging to the same family (Gramineae) and the same genus (Cymbopogon), adapted to the Caatinga and commonly confused with each other. The leaves of C. citratus are attributed activities such as calming, antispasmodic, analgesic and anti-inflammatory, and the leaves of C. winterianus are popularly known for their insect repellent potential. These species are included in the Living Pharmacies of the State of Ceará and contained in the Francisco José de Abreu Matos Medicinal Plant Garden (HPMFJAM), one of the only medicinal plant germplasm banks in Brazil. Thus, the present study aimed to perform a differential pharmacognostic study between the species Capim-santo (Cymbopogon citratus (DC) Stapf) and Capim-citronela (Cymbopogon witerianus Jowitt ex Bor) contained in the HPMFJAM. Fresh leaves of C. citratus and C. winterianus were collected from the site, and a part was dried in the shade to obtain the plant drug. In the samples obtained, phytochemical prospection tests, determination of desiccation loss and total ash content were performed. The samples were also submitted to essential oil extraction followed by yield calculation, Thin Layer Chromatography and Fourier Transform Infrared Spectroscopy with Attenuated Total Reflection (FTIR/ATR) with the purpose of identification and characterization of the major components of the essential oils. The data from the analyses of the essential oils by Cymbopogon Gas Chromatography contained in Professor Matos' scientific collection called Essencioteca were organized. The phytochemical prospection showed the presence of fixed secondary metabolites such as steroids, triterpenes, saponins, tannins and flavonoids. The yield of the essential oils from C. winterianus was higher than those from C. citratus. In the FTIR/ATR analyses, characteristic bands of functional groups present in the major components of the essential oil of each species were visualized, allowing differentiation. The results obtained indicated satisfactory applicability of the assays for quality control of the species, which showed promise in their phytochemistry, recommended to be the object of future studies that better investigate the applications of the plant drug and essential oils.