Estudio Fitoquimico y actividad antioxidante in vitro de hojas y flores de Passiflora manicata.

Abstract

The objective of this research was to conduct a phytochemical study of leaves and flowers of Passiflora manicata and the subsequently evaluation of their antioxidant activity. As a preliminary step to a qualitative and quantitative analysis it was necessary to check that the plant material meets quality standards. A phytochemical screening of extracts of different polarity was performed, which enable to identify its qualitatively chemical composition. By thin layer chromatography (TLC) the presumptive identification of flavonoid glycosides and aglycones was done. Through spectrophotometrically techniques it was possible to quantify the phenol and flavonoids total content of the extracts from ethyl acetate, methanol and 70 % alcohol. For the chromatographic analysis, an acid hydrolysis was done in order to quantify the aglycones coming from flavonoid glycosides. The evaluation of antioxidant activity in vitro was perfomed by radical scavenging assay with the radical 2,2 diphenyl-1-picrylhydrazyl (DPPH*); it was used as standard antioxidant Gallic acid. The results were expressed as inhibitory concentration 50 (IC50). The identified compounds in TLC were: vitexina, isoorientin, vitexin-2”-O-rhamnoside and isovitexin-2”-O-rhamnoside. Phenolic content ranged from 956.9892±81.181 to 1389.0967 ± 645.1613 mg/100 g of plant; being the hydroalcoholic extracto of leaves the one that presents a higher content of compounds. It was identified and quantified apigenin in leaves and flowers by liquid chromatography of high efficiency. The quantified apigenin in leaves of 331.9234 ± 3.097 µg/ml and for the flowers 3338.6306 ± 4.3089 µg/ml. As conclusion, the leaves have a higher antioxidant capacity compared to the flowers, so it is recommended further pharmacological studies about cicatrizing, anti-inflammatory and cytotoxic activity of Passiflora manicata leaves, in order to benefit its flavonoid content.