Contribución al estudio fitoquímico de partes aéreas de la especie vegetal Momordica Charantia (Cucurbitaceae) y evaluación de su capacidad antioxidante

Abstract

The species Momordica Charantia L. belonging to the genus Momordica of the family Cucurbitaceae commonly known as balsamina, lima bejeco, subicogen, gherkin and cucumber cimarron is a vine plant with bitter fruit; currently used as a medicinal plant, recognized for its hypoglycemic activity native to the tropical region, taking into account the importance of this species in traditional medicine, this work presents the contribution to the chemical and biological study of the aerial parts of the species Momordica Charantia , making an important contribution to the family Cucurbitaceae and especially to the genus Momordica, since it has few studies in our country. From the vegetable material collected in the municipality of Honda (Tolima) and identified in the herbarium of the National University of Colombia under collection number COL 596915 extraction was carried out using the cold maceration technique with 96% ethanol, obtaining 37.1 g (7.4% w / w) of total extract (E.EtOH.Mc.PA), where by means of the preliminary phytochemical study the presence of different secondary metabolites was determined qualitatively as: terpenes, tannins, cardiotonic glycosides and probably alkaloids being this consequent with phytochemical studies carried out on different species of the same genus such as Momordica balsamina (Mussa, 2006) or Momordica grosvenori (Takasaki et al., 2003). For the determination and chemical characterization of the secondary metabolites of the plant species Momordica charantia, a liquid-liquid fractionation was carried out continuously to the extract E.EtOH.Mc.PA with solvents of increasing polarity, obtaining the fractions of heptane (Fx.Hept.Mc .PA 1.22%), dichloromethane (Fx.DCM.Mc.PA 8.51%), ethyl acetate (Fx.AcOEt.Mc.PA 1.02%) and a hydroalcoholic residue (Fx.Hidroalc.Mc.PA 89.25%); These fractions were subjected to successive separations and purification using chromatography techniques, such as thin layer chromatography (CCD), preparative thin layer chromatography (CCDP) and column chromatography (CC), allowing the identification of two compounds called Kaguasaponin D and Momordicin II. , four mixtures of compounds, the first consisting of: an oxygenated terpene Epoxylinalool, a norisoprenoid Dihydroactinidiolide, a saturated fatty acid palmitic acid and an aliphatic triterpene identified as squalene, in the second mixture was found: a bicyclic terpenoid (3-Hydroxy) 5,6-epoxy-beta-ionone and a norisoprenoid 2-Cyclohexen-1-one-4-hydroxy-3,5,6-trimethyl-4- (3-oxo-1-butenyl), in the third mixture was found : an oxygenated terpene, linalool oxide, two phenolic compounds, cinnamic acid and benzoic acid, an indol heterocyclic compound and finally, for the fourth mixture, an oxygenated terpene was found. Eucalyptus and an esterified acid (propanoic acid, 2- ethyl-, 1- (1,1-dimethylethyl) -2-methyl-1,3-propanediol ester. The identification of the obtained mixtures was carried out by means of the coupled gas chromatography technique. to mass spectrometry, comparing the data with those reported in the NIST08 library. The determination of the antioxidant capacity was made by two methods by DPPH and ABTS, where I present 50% inhibitory effect in concentrations higher than 1000 ppm, for the total extract with an IC50 of 5734.1ppm, the fractions of ethyl acetate with an IC50 of 6178ppm and the hydroalcoholic residue with IC50 of 7251.8 ppm, by the DPPH radical method. Unlike the ABTS developed method, the ethanol extract showed an IC50 of 5513 ppm for the fractions of heptane with an IC50 of 5578ppm, the fraction of ethyl acetate with an IC50 of 4282.9ppm and a hydroalcoholic residue with an IC50 of 4375.2ppm, taking as reference the antioxidant uptake of trolox as a free radical for both methods, thus establishing the low antioxidant capacity of the aerial parts of the plant species Momordica Charantia due to the high concentrations in which it inhibits the radical.