Malhas fotoconversoras afetam o crescimento vegetativo, os processos oxidativos e as composições químicas volátil e fenólica de Lippia gracilis Schauer

Abstract

Lippia gracilis Schauer, belongs to the Verbenaceae family, popularly known as rosemary-de-table, is a native and endemic plant of the semiarid region of Northeast Brazil, recognized for a long time in popular medicine as a medicinal plant, used especially as an antimicrobial and antiseptic. The objective of this work was to evaluate the effect of photoconversion meshes on vegetative growth, oxidative stress, volatile and phenolic chemical composition in Lippia gracilis Schauer plants grown in pots. Cultivation of L. gracilis in full sun and using photoconverter meshes (blue, black and red) showed significant differences in the parameters evaluated. The plant length, leaf and stem dry matter were higher in the treatments with meshes (blue, black and red), while the photosynthetic pigments showed a significant increase in the treatment with blue mesh cultivation. In volatile chemical composition, the main compounds varied in all treatments. Cultivation under black mesh favored the increase of carvacrol, thymol and (E)-caryophyllene, whereas cultivation under blue and red mesh reduced the content of p-cymene, caryophyllene oxide and myrcene. Two glycosylated flavones from the ethanol extract, orientin and isoorietin, were isolated and subsequently quantified in the extracts of the different treatments, showing differences in content, according to the change in the cultivation system, with the cultivation in full sun showing the highest averages. The same was observed in the results of non-enzymatic oxidative stress, with the cultivation under blue mesh being less efficient in terms of the production of phenolic compounds.