CHROMATOGRAPHIC, INFRARED SPECTRAL AND ANTI-INFLAMMATORY STUDIES OF ETTHYL ACETATE AND METHANOL EXTRACT OF THE SEED OF D. EDULIS

Abstract

The seed powder of Dacryodes edulis were extracted using n-hexane, ethyl acetate and methanol by the cold maceration method. The crude Methanol and ethyl acetate extracts were then biologically assayed for acute toxicity (LD50) using the method of Lorke (1983). Anti-inflammatory activities of the crude were also assayed using male albino rats. The most biologically active (methanol extract) was separated using series of column chromatography (CC) and thin layer chromatography (TLC). The extractives coded DEF, DEH, DEJ and DEK, respectively were then characterized using infra-red (IR) spectroscopy and gas chromatography-mass spectrometry (GC-MS). All the results obtained were statistically analyzed using analysis of variance. The acute toxicity studies showed that even at higher concentration of 5000mg/kg, the extracts were not lethal to all the animals used. The anti-inflammatory analysis showed that the methanol extract had the highest anti-inflammatory activities. The IR for the methanol extractives showed the following λ max: (3500-3200) for the O-H stretch of alcohols and phenols, 3391.9 and 3354.6 for the N-H stretch of amines and amides, 3261.4 for the O-H stretch of carboxylic acids, 2948.3 and 2847.7 for the C-H stretch of alkanes, 1431.3 and 1386.6 for the C-H bend of alkanes and 1364.2 for C-H rocking of alkanes. Also 2836.5 for the C-H stretch of aldehydes, 2210.3 for the C=N stretch of nitriles,1736.9 1699.7 and 1013.8 for the C=O stretch of aldehydes, ketones and carboxylic acids. Equally 1643.2 and1636.9 for the C=C stretch of alkenes and 1576.7 for the C=C stretch of aromatic ring. These functional groups correspond to some of the compounds listed in the GC-MS library suggestions such as tetra- decanoic acid, hexa-decanoic acid, octadecanoic acid, vaccenic acid, catechol, 2, 4-di-tert- butylphenol and others. Presence of N-H group of amines and amides the GC-MS suggested presence of tri-(2-aminoethylamine,3,3,3-trifluoro-N-(2-fluoro-phenyl-2-(trifluoro methyl)methyl propionamide etc. The C=C of alkenes agreed with the suggested presence of cetene and bi-cyclo (10,10) tridec-1-ene and others. The non- toxic nature of the seed and its ability to reduce inflammations gives credence to its use in traditional medicine practice.