The yield and fatty oil components of the seed kernels of Annona squamosa L. (Family: Annonaceae) were determined by solvent extraction method and gas chromatography-mass spectrometry (GC-MS). Seeds were extracted with ethanol and further fractionated with n-hexane. The free radical-scavenging activities of both ethanolic and n-hexane fraction against 1, 1-diphenyl-2-picrylhydrazyl (DPPH) were determined by UV spectrophotometer at 517 nm. Phytochemical screening revealed the presence of numerous bioactive compounds including steroids, flavonoids, terpenoids, fatty acids, and different types of ester compounds. The prevailing compounds found in ethanolic fraction were n-hexadecanoic acid (10.08%), heptadecene-(8)-carbonic acid-(1) (29.68%), octadecanoic acid (3.61%), 9-octadecenoic acid (Z)-2,3-dihydroxypropyl ester (5.14%), ergost-5-en-3-ol (3.68%), stigmasta-5,22-dien-3-ol (5.93%), and y-sitosterol (8.25%). Compounds found in n-hexane fraction were mainly n-hexadecanoic acid (14.42%), 9,12-octadecadienoic acid (2.87%), cis-vaccenic acid (10.39%), 9-octadecenoic acid (7.03%), hexadecanoic acid, 2-hydroxy-1-(hydroxymethyl) ethyl ester (4%), 9-octadecenoic acid (Z)-, 2,3-dihydroxypropyl ester (13.33%), ergost-5-en-3-ol (4.04%), stigmasta-5,22-dien-3-ol, (3.beta.,22e) (6.07%), and y-sitosterol (10.87%). The crude fatty oil was converted into methyl esters and analyzed by GC-MS. Eleven compounds constituting 99.9% of the oil were identified. The presence of saturated and unsaturated fatty acids in ethanolic and n-hexane fraction of A. squamosa seed extract justify the use of this plant to treat many ailments in folk and herbal medicine. Both the fractions have shown significant antioxidant activity. The presence of phenolic compounds and unsaturated fatty acids are reported as possible contributors for antioxidant activity of seed extract.
Keywords: Annona squamosa; GC-MS; fatty oil; free radical scavenging; phytoconstituents; y-sitosterol.